WORLD INTELLECTUAL PROPERTY ORGANIZATION
Intemational Bureau
INTERNATIONAL APPLICATION PUBLISHED UNDER THE PATENT COOPERATION TREATY (PCT)
(51) International Patent Classification 7 1 (11) International Publication Number: WO 00/44287
A61B 17/00, 17/12, A61L 24/04, 31/04 _ _ .
(43) International Publication Date: 3 August 2000 (03.08.00)
(21) International Application Number: PCT/USO0/02262 (74) Agents‘ WONG: James» J- et 31-9 Ca"‘Pb6“ & Flores LU’: Suite
700, 4370 La Jolla Village Drive, San Diego, CA 92122
(22) International Filing Date: 28 January 2000 (28.01.00) (US)-
(30) Priority Data: (81) Designated States: AE, AL, AM, AT, AU, AZ, BA, BB, BG,
09/241,368 29 January 1999 (29.01.99) US BR, BY, CA, CH, CN, CR, CU, CZ, DE, DK, DM, EE,
ES, FI, GB, GD, GE, GH, GM, HR, HU, ID, IL, IN, IS, JP,
KE, KG, KP, KR, KZ, LC, LK, LR, LS, LT, LU, LV, MA,
(63) Related by Continuation (CON) or Continuation-in-Part MD, MG, MK, MN, MW, MX, NO, NZ, PL, PT, RO, RU,
(CIP) to Earlier Application SD, SE, SG, SI, SK, SL, TJ, TM, TR, "IT, TZ, UA, UG,
US 09/241,368 (CIP) US, UZ, VN, YU, ZA, ZW, ARIPO patent (GH, GM, KE,
Filed on 29 January 1999 (29.0l.99) LS, MW, SD, SL, SZ, TZ, UG, ZW), Eurasian patent (AM,
AZ, BY, KG, KZ, MD, RU, TJ, TM), European patent (AT,
BE, CH, CY, DE, DK, ES, FI, FR, GB, GR, IE, IT, LU,
(71) Applicant (for all designated States except US): PROHOLD MC, NL, PT, SE), OAPI patent (BF, BJ, CF, CG, CI, CM,
MEDICAL TECHNOLOGIES, INC. [US/US]; Suite 12, GA, GN, GW, ML, MR, NE, SN, TD, TG).
1444 Pioneer Way, El Cajon, CA 92020 (US).
(72) Inventors; and Published
(75) Inventors/Applicants (for US only): KRALL, Robert, E. With international search report.
[US/US]; 2728 Via Dieguenos, Alpine, CA 91901 (US). Before the expiration of the time limit for amending the
KERBER, Charles, W. [US/US]; 4444 Topa Topa Drive, claims and to be republished in the event of the receipt of
La Mesa, CA 91941 (US). KNOX, Kimberly [US/US]; 4444 amendments.
Topa Topa Drive, La Mesa, CA 91941 (US).
(54) Title: CYANOACRYLATES COMPRISING INHIBITORS AND AN OPACIFYING AGENT AS ADHESIVES
(57) Abstract
A composition comprising of a monomer component comprised of an alkyl cyanoacrylate and at least one inhibitor, and a second
component comprised of a resultant aggregate structure formed from an alkyl cyanoacrylate monomer, an alkyl esterified fatty acid and an
opacificant agent where said composition forms a resultant aggregate structure when said composition contacts an anionic environment. The
composition is useful for filling an existing space, e.g., the lumen of a blood vessel, a space created by a transiently placed extemal device,
e.g., a catheter or like device, a space created by a procedure, e.g., an excision or implantation of an object, e.g., a stent. The composition
is also useful for adhering tissue to tissue, or adhering tissue to a device. The composition has the property of polymerizing when it comes
in contact with an anionic environment, or when it is deployed in situ in an existing space.
FOR THE PURPOSES OF INFORMATION ONLY
Codes used to identify States party to the PCT on the front pages of pamphlets publishing intemational applications under the PCT.
Albania ES Spain LS Lesotho SI Slovenia
Armenia FI Finland LT Lithuania SK Slovakia
Austria FR France LU Luxembourg SN Senegal
Australia GA Gabon LV Latvia SZ Swaziland
Azerbaijan GB United Kingdom MC Monaco TD Chad
Bosnia and Herzegovina GE Georgia MD Republic of Moldova TG Togo
Barbados GH Ghana MG Madagascar TJ Tajikistan
Belgium GN Guinea MK The former Yugoslav TM Turkmenistan
Burkina Faso GR Greece Republic of Macedonia TR Turkey
Bulgaria I-IU Hungary ML Mali TT Trinidad and Tobago
Benin IE Ireland MN Mongolia UA Ukraine
Brazil IL Israel MR Mauritania UG Uganda
Belarus IS Iceland MW Malawi US United States of America
Canada IT Italy MX Mexico UZ Uzbekistan
Central African Republic JP Japan NE Niger VN Viet Nam
Congo KE Kenya NL Netherlands YU Yugoslavia
Switzerland KG Kyrgyzstan N0 Norway ZW Zimbabwe
Cote d’Ivoire KP Democratic People’s NZ New Zealand
Cameroon Republic of Korea PL Poland
China KR Republic of Korea PT Portugal
Cuba KZ Kazakstan R0 Romania
Czech Republic LC Saint Lucia RU Russian Federation
Germany LI Liechtenstein SD Sudan
Denmark LK Sri Lanka SE Sweden
Estonia LR Liberia SG Singapore
WO 00/44287 PCT/US00/02262
CYANOACRYLATES COMPRISING INHIBITORS AND AN OPACIFYING AGENT AS
ADHESIVES
FIELD OF THE INVENTION
This invention relates to cyanoacrylate
compositions useful as medical devices.
5 BACKGROUND OF THE INVENTION
Cyanoacrylate tissue adhesives have been in
clinical endovascular use since the 1970's. Liquid
acrylics are extremely useful as endovascular embolic
agents because of their ability to create permanent
10 vascular occlusion. They may, however, be difficult to
use technically as they have a variable and sometime
unpredictable polymerization time based on the operator
selection of an acrylic mix with either iodinated oil or
glacial acetic acid. The appropriate choice of
15 polymerization time depends on a number of variables,
including the transit time between arterial and venous
elements in the embolic target, the target volume, the
architecture of the target, for example, a fistula versus
nidus, which affects the relative endovascular
20 turbulence, and the method of injection (bolus, full
column, or wedge—flow arrest). Typical complications
associated with the use of liquid acrylics for
embolization occur when there is occlusion of normal
arterial branches or acrylic penetration into critical
25 venous outflow channels. Additionally, reflux of acrylic
around the delivery catheter tip can result in permanent
endovascular catheter adhesion, which may require
permanent catheter implantation. Overzealous attempts at
withdrawal can produce catheter fracture (and resultant
30 embolization of flow-directable distal catheter segment),
vascular damage with resultant dissection/occlusion, or
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avulsion of the involved vascular pedicle (with resultant
subarachnoid hemorrhage).
Alkyl alpha cyanoacrylates are a homologous
series of organic molecules which polymerize and can
adhere to moist living tissues. The methyl homolog has
been used in homeostasis and non—suture closure since
1960,
usefulness.
but its histoxicity severely limited its clinical
The synthesis of longer alkyl chain homologs
and the evaluation of these in various animal species
have shown that the histoxicity of cyanoacrylates could
be diminished without sacrificing their hemostatic and
tissue bonding properties. Extensive animal studies have
been completed using n-butyl and isobutyl homologs, and
preliminary human trials have been undertaken.
Polymerization speed is another function of
chain length. It has been reported that homologs with
six or more carbon atoms on the alkyl chain polymerize
almost immediately upon contact with moist tissues. The
n—butyl and isobutyl monomers require from four to 15
while the methyl homolog remains as a monomer
The
seconds,
for 30 to 55 seconds. ability to wet and spread
easily over the surface of an anticoagulated blood film
is common to homologs with alkyl chains containing four
The ethyl and propyl derivatives
or ITIOIE carbon atoms.
wet and spread poorly, and the methyl not at all.
Since the advent of NBCA (n—butyl—2—
cyanoacrylate), there has been very little advancement in
the science of "superglue" embolization of vascular
structures, primarily arteriovenous malformations (AVMs).
Certain properties of superglue are advantageous for
embolization, such as adhesion, the ability transform
from a liquid or solid state and rapid polymerization.
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However, these properties can be detrimental when present
to an excessive degree, in particular, adhesion which can
result in permanent catheter fixation. Rapid
polymerization allows the material to set in flowing
blood without passing through small channels into venous
structures. However, rapid polymerization may also
release amounts of heat that can cause damage to the
brain tissue.
surrounding tissue, for example,
Hydrophilic catheter coatings have been
developed in the hope of reducingthe risk of inadvertent
catheter
endovascular fixation during embolization due to
reduced bond strength between the hydrophillically coated
catheter and the adhesive. However, micro catheter
cyanoacrylate adhesion remains a problem during
intravascular embolization. Inadvertent gluing of the
catheter tip onto the artery is a well recognized and
distressing complication. Vessel rupture or occlusive
embolization of a detached catheter tip may occur if
excessive force is used to attempt to retrieve the
catheter. permanent intra vascular catheter
Fortunately,
fixation is usually well tolerated, nonetheless this
remains a highly undesirable event. An in vitro study
has shown that recently available hydrophilic micro
catheter coatings decrease catheter adhesion of both pure
normal butyl cyanoacrylate and mixtures of normal butyl
cyanoacrylate and ethiodized oil. Although
hydrophilically coated catheters have the potential of
decreasing the occurrence of inadvertent endovascular
the level of operator proficiency and
the actual
catheter fixation,
experience, and perhaps most importantly,
adhesive composition that is used stills play a major
role in these events.
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There exists a continuing unmet need for a
composition that has the correct amount of cohesiveness,
produces a robust rubbery casting, is tolerated by the
body, can trigger the appropriate amount of tissue
5 inflammation response and is radiopaque.
It has now been surprisingly found that such a
composition exists that has the requisite combination of
properties in cohesion, stability, body tolerance, low
catheter adhesion and radiopacity.
10 SUMMARY OF THE INVENTION
A composition comprising of a monomer component
comprised of an alkyl cyanoacrylate and at least one
inhibitor, and a second component comprised of a
resultant aggregate structure formed from an alkyl
15 cyanoacrylate monomer, an alkyl esterified fatty acid and
an opacificant agent where said composition forms a
resultant aggregate structure when said composition
contacts an anionic environment. the composition is
useful for filling an existing space, e.g., the lumen of
20 a blood vessel, or the sac of an aneurysm, a space
created by a transiently placed external device, e.g., a
catheter or like device, a space created by a procedure,
e.g., an excision or like procedure or implantation of an
object, e.g., a stent or like device, or a space created
25 by the composition; the composition is also useful for
adhering tissue to tissue, or adhering tissue to a
device. The composition has the property of polymerizing
when it comes in contact with an anionic environment, or
when it is deployed in situ in an existing space, e.g.,
30 the lumen of a blood vessel, or the sac of an aneurysm, a
space created by a transiently placed external device,
e.g., a catheter or like device, a space created by a
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procedure, e.g., an excision or like procedure or
implantation of an object, e.g., a stent or like device,
or a space created by the composition.
BRIEF DESCRIPTION OF THE DRAWINGS
5 No drawing are included.
DETAILED DESCRIPTION OF THE INVENTION
The present invention provides a composition
comprising of a monomer component comprised of an alkyl
cyanoacrylate, at least one inhibitor and a second
10 component that functions as a opacificant agent and
polymerization retardant. The composition is useful for
filling, occluding, partially filling or partially
occluding an unfilled volume or space in a mass (“a
space”). In particular, the composition is useful for
15 filling an existing space, e.g., the lumen of a blood
vessel, or the sac of an aneurysm, a space created by a
transiently placed external device, e.g., a catheter or
like device, a space created by a procedure, e.g., an
excision or like procedure or implantation of an object,
20 e.g., a stent or like device, or a space created by the
composition; the composition is also useful for adhering
tissue to tissue, or adhering tissue to a device. The
composition has the property of polymerizing when it
comes in contact with an anionic environment, or when it
25 is deployed in situ in an existing space, e.g., the lumen
of a blood vessel, or the sac of an aneurysm, a space
created by a transiently placed external device, e.g., a
catheter or like device, a space created by a procedure,
e.g., an excision or like procedure or implantation of an
30 object, e.g., a stent or like device, or a space created
by the composition.
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Another aspect of the present embodiment is
where the second component is comprised of a halogenated
oil. Preferred are iodinated and brominated oils, such
as Ethiodol, Lipiodol and Pantopaque. Most preferred is
Ethiodol.
One embodiment of the present invention is
where the second component is Ethiodol.
Another aspect of the present embodiment is
where the second component is comprised of a resultant
aggregate structure, i.e., an oligomer or polymer, formed
from a composition of alkyl cyanoacrylate monomer, an
alkyl esterified fatty acid and an opacificant agent.
Another aspect of the present embodiment is
where the monomer component is comprised of an alkyl
cyanoacrylate monomer, and at least two inhibitors, a
preferred aspect is where the monomer component is
comprised of an alkyl cyanoacrylate and at least three
inhibitors, an especially preferred aspect is where the
monomer component is comprised of 2—hexyl cyanoacrylate
and at least one inhibitor. An especially preferred
aspect is where the monomer component is comprised of
2—hexyl cyanoacrylate and at least two inhibitors. A
most especially preferred aspect is where the monomer
component is comprised of 2—hexyl cyanoacrylate, and
three inhibitors, particularly, most especially preferred
is the aspect where one of the inhibitors is selected
from hydroquinone, p—methoxyphenol or phosphoric acid. A
most especially preferred aspect is where the monomer
component is comprised of 2—hexyl cyanoacrylate, and
three inhibitors, where the three inhibitors are
hydroquinone, p-methoxyphenol and phosphoric acid. The
quantity of inhibitors used is measured in terms of parts
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per million of alkyl cyanoacrylate. Preferably,
hydroquinone is in the range of about 50 to 150 parts per
million (PPM), p—methoxyphenol in the range of about 50
to 150 PPM, and phosphoric acid in the range of about 125
to 375 PPM, more preferred is hydroquinone in the range
of about 75 to 125 PPM, p~methoxyphenol in the range of
about 75 to 125 PPM, and phosphoric acid in the range of
about 187.5 to 312.5 PPM,
hydroquinone in the range of about 95 to 105 PPM,
and most preferred is
p—methoxyphenol in the range of about 95 to lO5 PPM, and
phosphoric acid in the range of about 200 to 300 PPM.
An especially preferred embodiment of the
present invention is a composition comprised of the
present monomer component, and a second component
comprising of a resultant aggregate structure, i.e., an
oligomer or polymer, formed from 2-hexyl cyanoacrylate
monomer, an alkyl esterified fatty acid and an
opacificant agent, most especially preferred is where the
alkyl esterified fatty acid is ethyl myristate, also most
especially preferred is where the opacificant agent is
gold.
Another embodiment of the present invention
provides a method for filling, occluding, partially
filling or partially occluding an unfilled volume or
space in a mass. The types of unfilled volumes or spaces
within the scope of the present invention includes, but
are not limited to the following instances.
For example, one aspect of the present
embodiment is a method of filling, occluding, partially
filling or partially occluding an existing space, such
as, a lumen of a passageway in the body, e.g., a blood
a duct, or a fistula. Examples of
vessel, an aneurysm,
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the types treatments covered by this method of use,
include but are not limited to the following. The
present invention is useful as a method of treating
arteriovenous malformations (AVM) where the blood
vessel(s) that feed the AVM are occluded thereby cutting
off the blood supply to the AVM.
is useful as a method to ablate diseased or undesired
The present invention
tissue by cutting off the tissue’s blood supply. In
particular, the present invention is useful as a method
supply, where
occluded
of treating a tumor having a discrete blood
the blood vessel(s) that feed the tumor are
thereby cutting off the blood supply to the tumor
resulting in diminished growth or death of the tumor.
The present invention is useful as a method of preventing
or mitigating the development of an aneurysm by creating
a partial occlusion at a location in the blood vessel
selected to modify the fluid dynamics within the vessel
to mitigate the formation or development of an aneurysm.
The present invention is useful as a non—surgical method
symptomatic uterine leiomyomas by
This method has
of treating
embolizing/occluding the uterine artery.
been reported using a non alkyl cyanoacrylate composition
in J.Vascular and Intervention Radiology, lO:89l—894,
July—August 1999. The present invention is useful as a
method of sterilizing a female mammal by occluding the
fallopian tubes thereby preventing the passage of the
eggs from the ovaries to the uterus. The use of an
occluding agent to sterilize a female mammal is disclosed
5,989,580 “Method of Sterilizing
in U.S. Patent No.
Female Mammals,” herein incorporated by reference. The
methods disclosed in this patent can be advantageously
applied using the compositions of the present invention,
and are within the scope of the present invention. The
present invention is useful for obliterating the left
atrial appendage. The left atrial appendage is derived
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from the left wall of the primary atrium. It has been
observed that patients with atrial fibrillation have a
predilection for thrombus to form in the in the left
atrial appendage. A review of this condition and the
current status of treatment is disclosed in the article,
“Left Atrial Appendage: structure, function, and role in
et. al. The present
thromboembolism” N.M. Al—Saady,
invention provides an advantageous method of obliterating
the left atrial appendage.
Another aspect of the present embodiment is a
method of filling, occluding, partially filling or
partially occluding a space created by an external
device, such as, a catheter balloon. Examples of the
types of treatments covered by this method of use
include, but are not limited to the following. The
present invention is useful as a method of treating an
aneurysm by filling the space within the aneurysm with a
composition of the present invention, where the
composition polymerizes in the space within the aneurysm,
thereby preventing the rupture of the aneurysm. This
treatment can be effected using the present invention
catheter
with any number of catheters, catheter coils,
wires or catheter balloons commercially available.
Examples of such devices are commercially available from
For instance, Micro Therapeutics, Inc., 2
California 92618,
SOUICGS .
markets a line of
Goodyear, Irvine,
medical devices, such as, the Rebarm Micro Catheter,
Equinox“ Occlusion Balloon System and Silverspeedm
guidewires. U.S. 5,882,334
“Balloon/delivery Catheter Assembly with Adjustable
Similarly, Patent No.
Balloon Positioning,” assigned to Target Therapeutics,
Inc., and incorporated herein by reference, is directed
to a catheter assembly for delivering compositions, such
as, those of the present invention.
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Another aspect of the present embodiment is a
method of filling, occluding, partially filling or
partially occluding a space created or resulting from a
procedure, such as with the excision of tissue, or
insufflation. Examples of the types of treatments
covered by this method of use include, but are not
limited to the following. The present invention is
useful as a method of treating or mitigating capillary
oozing.
Another aspect of the present embodiment is a
method of filling, occluding, partially filling or
partially occluding a space created by the placement or
implantation of an object,
such as, a medical device.
Examples of the types of uses covered by this method of
use include, The
but are not limited to the following.
present invention is useful as a method of restoring the
normal fluid dynamics at the peripheral edges of a
vascular stent by filling the dead spaces between the
stent and the lumen wall created by the implantation of
the stent.
Another aspect of the present embodiment is a
method of filling, occluding, partially filling or
partially occluding a space created by the composition
itself, such as, where the composition is used as a
bulking agent. Examples of the types of uses covered by
this method of use include, but are not limited to the
following. For example, a method of recreating the
normal contours to skin following an adverse event, such
as, physical trauma.
Another embodiment of the present invention
provides a method of affixing therapeutics,
chemotherapeutics, radiation delivery devices, gene
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therapy compositions to a desired location where the
active agents can be advantageously maintained in
proximity to the desired location. The active agent is
then release gradually as the resultant aggregate
structure from the composition of the present invention
is biodegraded. the composition of the
Alternatively,
present invention can be modified to allow for a specific
rate of delivery. This use is particularly beneficial in
the treatment of tumors that are ideally treated by
localized dosages of chemotherapy or radiation. An
advantage of this method is that the patient would not be
subjected to as large of a dose of the therapeutic or
if the therapeutic or
Another
radiation as would be necessary,
radiation was administered on a systemic basis.
advantageous use the present invention is for the
delivery of DNA compositions used in gene therapy. A
long standing problem in the gene therapy arts has been
the inability of practitioners to deliver the DNA
therapeutic to the locales in the body most ideally
suited for the treatment. The present invention provides
a method of affixing the DNA composition at a desired
site, where the active agent is then slowly released over
a period time as the composition of the present invention
biodegrades. Alternatively, a composition of the present
invention can be modified to release the active agent in
a controlled delivery manner.
Another embodiment of the present invention
provides a method of utilizing magnetically controlled
particles inbedded in a composition of the present
invention to deploy the composition to a desired
“Magnetic Probe for the Stereotaxic Thrombosis
J.F., et. al,
1967 April,
location,
of Intracranial Aneurysms,” Alksne, Journal
of Neurology, Neurosurgery and Psychiatry,
30(2):l59—62; “Magnetically Controlled Focal
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Intravascular Thrombosis in Dogs” Alksne, J.F., et. al,
1966 Nov, 25(5):5l6—25;
“Thrombosis of Intracranial Aneurysms - An experimental
Journal of Neurosurgery,
approach utilizing magnetically controlled iron
particles” Alksne, J.F., et. al, Radiology 1966 Feb.
86(2):342—3
Another embodiment of the present invention
provides a method of adhering, joining, connecting or
affixing a first section of tissue to a second section of
tissue. Examples of the types of uses covered by this
method of use include, but are not limited to the
following. The present invention is useful as a method
of adhering, joining, or connecting two blood vessels,
anastimosis, where blood vessels are quickly and
e.g.,
efficiently adhered, under surgical
The
joined or connected,
conditions without the use of sutures or staples.
present invention is useful as a method of treating
primary wounds or wounds that require immediate
intervention, such as, trauma wounds, where the
compositions of the present invention are used to
temporarily close the wound to minimize the lost of
fluids due to evaporation, and to mitigate infection.
Another embodiment of the present invention
provides a method of adhering, joining, connecting, or
affixing tissue to a non—tissue surface, such as a
medical device. Examples of the types of uses covered by
this method of use include, but are not limited to the
following. The present invention is useful as a method
of implanting or securing venous valves, replacement
heart valves, or stents at their desired location.
The aforementioned uses are possible because
the compositions of the present invention remain in a
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controllable state for a period of time in excess of 1
second after being deployed from an administration
device. This property allows the practitioner to
incrementally maneuver the deployment of the composition
to its most ideal location, even when the composition has
been partially deployed distal the the deployment device.
For instance, the compositions of the present
invention have adequate cohesion to maintain its
continuity once it is outside of the deployment device.
Without adequate cohesion the composition would break
into smaller aggregates dispersing into the blood flow.
For instance, the compositions of the present
invention have appropriate adhesion properties so that
when desired a deployed composition adheres to the
immediate location where it is deployed so that the
resultant aggregate of the monomer is placed where it is
desired.
The compositions of the present invention have
such that, the practitioner can
polymerization rate,
effect the desired amount of penetration of the
composition into a particular type of space. A
composition that polymerizes too quickly would hinder
penetration, conversely a composition that polymerizes
too slowly would make it difficult to precisely place the
polymerized composition resultant aggregate of the
monomer .
Another embodiment of the present invention
provides a method for selectively creating an embolic
duct, fistula or
blockage in the lumen of a blood vessel,
other like body passageways.
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Another embodiment of the present invention
provides a method of treating arteriovenous malformation
(AVM)
DEFINITIONS
As used herein the terms "adhesion" or
"adhesive" means the characteristic or tendency of a
material to be attracted to the surface of a second
material. Adhesion occurs as the result of interactions
between two materials. Depending on the characteristics
of the second material relative to the first material,
For a single material,
the
adhesion may or may not occur.
e.g., the composition of the present invention,
presence of adhesion is demonstrated by a material
sticking to the wall of a lumen of blood vessel, i.e.,
there is adhesion between the material and the lumen
wall.
demonstrated for the same material where a micro—catheter
Conversely, the absence of adhesion is
tip used to deposit the material can be removed from the
material, i.e., there is little adhesion between the
material and micro—catheter tip.
As used herein the term "alkyl" refers to a
carbon chain of one to sixteen carbon atoms, where the
carbon atoms can be linear or branched.
As used herein the term “anionic environment”
or “an—ionic environment” refers to an environment that
is non—ionic. This an environment that is devoid of
charged ions, or where the charged ions are complexed
with other molecules which effectively neutralize their
For example, a solution of water and a sugar,
and blood,
charge.
is an anionic environment.
such as, dextrose,
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As used herein the term "lower—alkyl" refers to
a carbon chain of one to eight carbon atoms, where the
carbon atoms can be linear or branched. Examples of
lower-alkyl moieties include but are not limited to
5 methyl, ethyl, n—butyl, isobutyl, pentyl, n—hexyl,
2—hexyl, n-heptyl, 2-heptyl, n—octyl and 2—octyl.
As used herein the term "branched alkyl" refers
to a carbon chain of one to sixteen carbon atoms where
the carbon chain contains at least one secondary or
10 tertiary substituted carbon atom.
As used herein the term "branched lower—alkyl"
refers to a carbon chain of one to eight carbon atoms
where the carbon chain contains at least one secondary or
tertiary substituted carbon atom, for example, 2—hexyl,
15 isobutyl, 2—heptyl and 2—octyl.
As used herein the term "cohesion" or
"cohesive" means the characteristic or tendency of a
material to stick together to itself. For example, this
characteristic is demonstrated by a material or
20 composition remaining intact as a single mass when
introduced into a stationary fluid, or a fluid stream in
motion, such as, blood. Lack of cohesive integrity
results in the composition breaking up into multiple
smaller subunits.
25 As used herein the term "embolic agent" refers
to a non—naturally occurring composition introduced into
a body cavity or the lumen of a blood vessel, duct,
fistula or other like body passageways for the purpose of
forming an embolic block.
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As used herein the term "embolic block" or
"embolic blockage" or occlusion refers to the end result
from the administration of a composition useful as an
embolic agent. The resulting embolic block mechanically
blocks, the lumen of a blood
totally or partially,
duct, fistula or other like body passageways; or
in a like manner forms an occlusion within a cavity,
vessel,
such
as an aneurysm .
As used herein the term "alkyl cyanoacrylate
monomer" refers to the chemical entity of the general
structure H2C=C(CN)—C(O)O—R, where R is an alkyl moiety of
one to sixteen carbon atoms, linear or branched,
saturated or unsaturated, having the physical
characteristic of being able to form the corresponding
alkyl cyanoacrylate.
As used herein the term "alkyl cyanoacrylate
polymer" means an oligomer or polymer resulting from the
polymerization of a alkyl cyanoacrylate monomer.
As used herein the term "alkyl esterified fatty
acid" means a fatty acid derivatized to form an ester
functional group with a alkyl moiety, such as ethyl
These compounds are formed with an alkyl
butyl,
and carboxylic acids with alkyl
myristate.
moiety, such as, methyl, ethyl, propyl, pentyl,
hexyl, heptyl, and octyl;
side chains ranging from l carbon, i.e., acetic acid,
through to and including 17 carbons atoms in length, such
as, proprionic, butyric, isobutyric, valeric, isovaleric,
pivalic, lauric, myristic, palmitic and stearic acids.
As used herein the term "opacificant agent" is
compound or composition which selectively absorbs or
deflects radiation making the material visible under
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x—ray, or any like imaging technique. Typically such
agents include, iodinated oils, and brominated oils, as
well as commercially available compositions, such as
Lipiodol and Ethiodol. These commercially
Pantopaque,
available compositions acts as opacificant agents, and
also dilute the amount of liquid monomer thereby slowing
the rate of polymerization. In addition certain metals,
such as, gold, platinum, tantalum, titanium, tungsten and
barium sulfate and the like, have properties enabling
them to act as opacificant agents.
As used herein the term "polymerization" refers
to the chemical process where identical monomer units
react chemically to form larger aggregates of said
monomeric units as oligomers or polymers.
As used herein the term "polymerization
retardant" means an agent that can stop or slow down the
rate of polymerization. Examples of such agents are pure
phosphoric acid, and 85% phosphoric acid. Certain
opacificant agents, such as Pantopaque, Lipiodol and
Ethiodol can also function as a polymerization retardant
by diluting the amount of liquid monomer and hence
slowing polymerization rate.
As used herein the term “a space” refers to an
unfilled volume or cavity in a mass. Examples of such
spaces, include but are not limited by the following, an
existing space within a mass, such as, the lumen of a
blood vessel, the sac of an aneurysm; a space created by
a transiently placed external device, such as, a catheter
such as,
or like device; a space created by a procedure,
an excision or like procedure; a space created by
implantation of an object, such as, a stent or like
device; or a space created by the composition.
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As used herein the term "stability" refers to
the ability of a monomer component to resist degradation
or polymerization after preparation but prior to use.
As used herein the term "inhibitor agent"
refers to an agent which stabilizes a monomer composition
by inhibiting polymerization. Within the context of the
current invention, this term refers to agents that
stabilize and inhibit polymerization by various
mechanisms. By altering the amounts of one or more
inhibitor agents, the rate of polymerization can be
controlled. Inhibitor agents have different modes of
activity, for example, hydroquinone acts primarily to
inhibit high energy free radicals; p—methoxyphenol acts
primarily to inhibit low energy free radicals; and
phosphoric acid influences the rate of anionic
polymerization.
As use herein the term “Neuracryl M” refers to
the composition comprising of a monomer component (“Ml”)
comprised of 2—hexyl cyanoacrylate, hydroquinone,
p—methoxyphenol and phosphoric acid, and a second
component (“M2”) comprising of a resultant aggregate
structure formed from 2—hexyl cyanoacrylate monomer,
the term "M1"
and the
ethyl myristate and gold. As noted above,
refers to the monomer component of Neuracryl M,
term "M2" refers to the second component of Neuracryl M.
As used herein the term “deployment device”
refers a device used to deploy compositions, such as,
those of the present invention. Examples of such
devices, include but are not limited to the following.
Irvine, California
the Rebarm Micro
Inc., 2 Goodyear,
Micro Therapeutics,
92618,
Catheter,
markets medical devices, such as,
Equinox” Occlusion Balloon System and
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Silverspeedm guidewires, that are used in conjunction for
treating conditions such as those within the present
invention. The devices disclosed in U.S. Patent No.
5,882,334 “Balloon/delivery Catheter Assembly with
5 Adjustable Balloon Positioning,” incorporated herein by
reference, directed to a catheter assembly for delivering
compositions.
Nomenclature
The compound 2—hexyl cyanoacetate is depicted
10 as follows, and also as Formula 3 in Schemes A and B.
The compound 2—hexyl cyanoacrylate is depicted
as follows, and also as Formula 5 in Scheme B.
O
CH /
zfi/“\O
CN
The present invention is a composition formed
from alkyl cyanoacrylate monomeric units, such as,
15 n-butyl, isobutyl, and 2—hexyl cyanoacrylate with at
least one inhibitor agent, such as hydroquinone,
p—methoxyphenol and phosphoric acid. The composition
forms into its resultant aggregate structure, i.e., an
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when it comes in contact with an
The
oligomer or polymer,
anionic environment, such as, blood or tissue.
resultant aggregate composition has characteristics which
makes it particularly well suited as an embolic agent.
The composition of the present invention
possess the following properties, which are desirable in
an embolization agent.
1) The composition can be prepared and maintained as a
monomeric component and second component until needed.
2) The composition has the ability to reliably and
predictably change from a liquid state to a solid state,
for its introduction and controlled
duct,
which is essential
placement into the lumen of vessel, fistula or
other like body passageways.
3) The composition has low viscosity, which is essential
for its administration by syringes and micro—catheters or
other like devices.
4) The composition has cohesive characteristics such that
when the composition in administered into an anionic
fluid environment, such as blood, the composition forms a
single aggregate structure.
5) The composition has adhesive characteristic such that
duct,
but not to the degree where
it attaches to the lumen of vessel, fistula or
other like body passageways,
the device depositing the composition will become fixed
to it before the practitioner can remove it.
6) The composition causes mild tissue inflammation,
sufficient to cause scarring, but not so severe to cause
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the formation of pus. Scar formation is necessary to
maintain the functionality of the embolic block after the
composition has biodegraded, or otherwise eliminated from
the lumen.
7) The composition is sufficiently stable to
biodegradation to allow for scarring to occur.
8) The composition is radiopaque. Although not necessary
for its function as an embolic agent, radiopacity allows
the embolic block to be observed with x—ray or other such
imaging techniques.
9) The rate of heat released during polymerization of the
composition is low enough such that the heat does not
adversely effect surrounding tissues that may be heat
sensitive, such as brain tissue.
10) The composition and its biodegradation products are
sufficiently non—histotoxic and non—cytotoxic so that its
presence is well tolerated in the body.
The composition of the present invention is
used by combining the monomer component and second
the invention
duct,
component. Upon mixing of the components,
is administered into the lumen of a blood vessel,
fistula or other like body passageways. The
characteristics of the present invention permit its
accurate placement in the lumen. Contact with an anionic
environment, such as blood, or tissue causes the
composition to polymerize. The size of the resultant
embolic block formed is determined by the amount of
composition administered.
The characteristics of the composition of the
invention can be modified for a specific purpose or
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environment for which the embolic agent is intended to be
utilized. For example, changes in the length and
isomeric configuration of the alkyl side chains can alter
the brittleness of the resultant aggregate of
cyanoacrylate monomers. Alkyl chains that result in the
formation of smaller aggregates tend to be less brittle,
while larger aggregates tend to be less flexible. In
addition, by combining monomers with different alkyl side
chains the characteristics of the resultant polymer can
be modified to what is optimal for a desired application.
Cyanoacrylates generate heat as they change
The amount and rate of
from monomeric to polymeric form.
heat released, if excessive, can have a detrimental
effect on the living tissue proximate to the vessel.
Control of the amount and rate at which heat is release
during polymerization is critical to the utility of
composition.
Preparation of the Monomer Component
The monomer component of the present invention
is prepared by forming the desired precursor ester from
the corresponding alkyl alcohol and cyanoacetic acid
resulting in the desired alkyl cyanoacetate as depicted
in Scheme A. The starting materials for this reaction
are commercially available, for example from Aldrich
Chemical Company, Sigma Chemical Company or Fluka
Chemical Company, or can be prepared following procedures
known to those of ordinary skill in the art.
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o 0
cN~)J\oH + R-0” ——> CNAO-R
1 2 3
Sdmnelk
The compound of Formula 2 can be any alkyl alcohol, where
R is from one to sixteen carbons, including but not
limited to alcohols based on alkyl groups, such as,
methyl, ethyl, propyl, butyl, pentyl, hexyl, heptyl,
5 heptyl, octyl, nonyl, deca, undeca, dodeca, trideca,
tetradeca, pentadeca and hexadeca, where the preceding
moieties are linear (e.g., n—propyl, n—butyl, n—pentyl)
or variously branched, such as sec—butyl, iso—butyl,
tert-butyl, iso—propyl, 2—butyl, 2—pentyl, 2-hexyl,
10 2—heptyl, 2—octyl and the like. Particularly
advantageous alcohols are those disclosed in U.S. Patent
3,728,375 entitled "Cyanoacrylate Adhesive Compositions",
which is hereby incorporated by reference. Especially
preferred are n—butyl, iso—butyl and 2-hexyl alcohols.
15 About 1 molar equivalents of the compounds of
Formula 1 and Formula 2 are combined in a solvent like
toluene at about 100 ml/molar equivalents. To this
mixture is added a catalytic amount (about 1.0 x 10'4
molar equivalents) of p-toluene sulfonic acid. The
20 mixture is stirred and heated to reflux. The preparation
ideally yields the desired alkyl cyanoacetate at a purity
level of about 95%. The experimental conditions can be
readily modified by one of ordinary skill in the art
without deviating from the present invention. Aspects
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such as, solvent selection, reaction time,
temperature
and choice of reagents are well within the skill of one
of ordinary skill in the art. If necessary, the material
can be further purified using multiple distillations and
purification techniques and procedures known to those of
such as water extraction,
and the like.
ordinary skill in the art,
vacuum distillation, column chromatography,
Preparation of alkyl cyanoacrylate
The desired alkyl cyanoacrylate monomer
component of the present invention is synthesized from
the alkyl cyanoacetate by reacting the it in a Knoevengel
type reaction as depicted in Scheme B.
O Q 0
+ /u\ ____,
CNAO-R H H CH2 0"‘
CN
3 4 5
SdrnbB
About 1 molar equivalents of formaldehyde (Formula 4),
which is prepared from paraformaldehyde, and piperidine
(at about 0.33 ml/molar equivalents) are combined in a
solvent, such as methanol (at about 166 ml/molar
equivalents). To this mixture is added about 1 molar
equivalents of previously prepared alkyl cyanoacetate
(Formula 3) in a dropwise manner. The reaction mixture
is refluxed with stirring yielding the desired alkyl
The reaction mixture
cyanoacrylate polymer (Formula 5).
is further processed with about 0.2 to 0.7 molar
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equivalents, preferably about 0.2 to 0.6 molar
equivalents of phosphorous pentoxide yielding the desired
alkyl cyanoacrylate. Care must be taken during
purification steps to prevent the compound of Formula 5
from polymerizing; To this end the system is treated
with trace amounts of sulfur dioxide, and receiver flasks
are treated with hydroquinone and 85% phosphoric acid.
After initial purification, the desired alkyl
cyanoacrylate is further purified using multiple
distillations, or other purification techniques known to
such as,
and the like.
those of ordinary skill in the art, vacuum
distillation, spinning band column,
Formulation
The monomer component of the present invention
comprises of at least one alkyl cyanoacrylate and at
least one inhibitor agent. Typical inhibitors
appropriate for cyanoacrylates are, for example,
hydroquinone, p—methoxyphenol, pure phosphoric acid, and
alkyl carboxylic acids, where the alkyl moiety ranges
from 1 carbon, e.g., acetic acid, through to 15 and 17
carbons atoms in length, palmitic and stearic
i.e.,
acids, respectively; and phosphoric acid at varying
percentage solutions. Preferably hydroquinone,
p—methoxyphenol, and phosphoric acid are used,
individually or in combination.
Different inhibitors have different physical
characteristics and thereby functions to alter the final
hydroquinone
properties of the composition. For example,
is primarily an inhibitor for high energy free radicals;
p—methoxyphenol is primarily an inhibitor for low energy
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free radicals; and phosphoric acid acts to control or
inhibit anionic polymerization and the rate of such
polymerization.
The quantity of inhibitors used is measured in
terms of parts per million of alkyl cyanoacrylate. For
for 2—hexyl cyanoacrylate, hydroquinone is in
(PPM),
example,
the range of about 50 to 150 parts per million
p-methoxyphenol in the range of about 50 to 150 PPM, and
phosphoric acid in the range of about 125 to 375 PPM,
more preferred is hydroquinone in the range of about 75
to 125 PPM, p-methoxyphenol in the range of about 75 to
125 PPM,
to 312.5 PPM,
and phosphoric acid in the range of about 187.5
and most preferred is hydroquinone in the
range of about 95 to 105 PPM, p-methoxyphenol in the
range of about 95 to 105 PPM,
range of about 200 to 300 PPM.
and phosphoric acid in the
The second component functions as an
opacificant agent and a polymerization retardant.‘ To
this end, the second component can be an iodinated oil,
such as Ethiodol, or a brominated oil. Typically the
iodinated oil is mixed as some percent of the total
volume of the final composition. The percentage solution
of iodinated oil used will influence the polymerization
rate and opacity of the composition. Generally
advantageous ranges are from about 17% to 66%, preferably
about 33%.
Alternatively, the second component can be a
composition comprising, a opacificant material, such as
gold, platinum, tantalum, titanium, tungsten and barium
sulfate and the like; an alkyl cyanoacrylate polymer
where the.
material, and an alkyl esterified fatty acid,
for example, alkyl butyrate to 17
fatty acids have 3,
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carbons, for example, alkyl stearate, preferred are,
alkyl laurate, alkyl myristate, alkyl palmatate, and
alkyl stearate, most preferred is alkyl myristate, and
most especially prefereed is ethyl myristate.
5 The opacificant material is used in a fine
powder form, typically, with individual particles sized
no larger than about 7 microns in diameter, preferably
about 5 microns, most preferred about 2 microns and most
especially preferred is 1 micron or smaller.
10 The amount of opacificant material used
relative to alkyl cyanoacrylate polymer will vary
according to the specific materials. Factors that
influence the determination of the ratio include the
amount and size of the particles that are being coated by
15 the alkyl cyanoacrylate polymer. For example, for
2—hexyl cyanoacrylate and gold, 2 g of 2—hexyl
cyanoacrylate is used per 100 g of powdered gold
(particle size of about 5 i 2 microns) being coated. The
amounts vary accordingly with the opacificant material
20 being coated by the alkyl cyanoacrylate. The alkyl
cyanoacrylate and opacificant material are mechanically
mixed by processing the alkyl cyanoacrylate into small
particulate masses, and mixing with the finely powdered
opacificant material. The alkyl cyanoacrylate polymer
25 coated material is then stored in an esterified fatty
acid, which serves as a medium where the alkyl
cyanoacrylate polymer coated material is maintained prior
to use, and as a medium, which when contacted with the
monomer component will not interfere with the
30 polymerization of the composition. The unsealed storage
containers, preferably appropriately sterilized bottles
and caps or the like, with the cyanoacrylate polymer
suspension is then treated with ethylene oxide, or
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alternatively ketene. This treatment should occur no
later than about 48 hours after completion of the coating
process, preferably within 24 hours. The treatment
process provides sterilization and stabilization of the
5 alkyl cyanoacrylate polymer coated material and follows
standard procedures for ethylene oxide use, i.e.,
positioning the containers so that they are amply exposed
to the gas for a sufficient period of time.
Polymer M
10 The characteristics of the composition of the
invention can be modified for a specific application or
environment in which the composition is intended to be
utilized. For example, changes in the length and
isomeric configuration of the alkyl side chains can alter
15 the brittleness of a polymer formed from a cyanoacrylate
monomer. Alkyl chains that result in the formation of
smaller aggregates tend to be less brittle, while larger
aggregates tend to be less flexible. Another method of
modifying the characteristics of a polymer is to use a
20 composition comprising of two or more types of alkyl
cyanoacrylate monomers in combination with the
appropriate inhibitors.
For example, a composition comprised of a
monomer component comprising of 2—hexyl cyanoacrylate,
25 hydroquinone, p—methoxyphenol and phosphoric acid; and a
second component comprising of 2—hexyl cyanoacrylate
polymer, gold, and ethyl myristate results in Polymer M.
A qualitative survey of Polymer M is shown in
Table A. The physical characteristics disclosed are
30 readily recognized by those of ordinary skill in the art
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as being relevant to the applications for which the
polymers are used.
Table A
Characteristics Polymer M
5
polymerization profile polymerizes to semi—solid
to soft—solid on contact
with tissue or blood
10
Polymer M has excellent cohesion properties.
15 When introduced into a stationary fluid, or a fluid
stream in motion, such as, the lumen of a blood vessel or
other like passageway, the composition tend to stick
together to itself remaining intact as a single mass or
aggregate. This permits the composition to be discretely
20 deployed or placed at the desired location without the
hazard of having potions of the composition breaking away
and depositing at undesired locales. Polymer M has
viscosity properties that permit the injection of the
liquid composition into a lumen of a blood vessel, duct,
25 fistula or passageway in the body without using excessive
pressure.
With these properties Polymer M is ideally
suited for applications where the composition must
penetrate further into anionic environment before
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arriving at the point of final placement. A preferred
use is the treatment of arteriovenous malformations, also
“AVM”. Polymer M is also ideally suited for the
known as
treatment of longer type urinary fistulas, this is
because preferred treatment requires greater penetration
into cavity space by the liquid composition. Additional
applications suited for Polymer M are creating a tubal
occlusion, For example, a
and surgical adhesions.
composition of the present invention is applied to raw
intraperitoneal tissue to prevent the tissue from
adhering to itself or other tissue.
Administration
The composition of the present invention are
administered with any type of commercially available
needle, catheter devices, or stereotaxic placement
devices, preferably in conjunction with imaging
technology that provides the practitioner with guidance
as to the placement of the composition. Such devices and
methods are readily known to those of ordinary skill in
art. For example in U.S. Patent 5,925,683 “Liquid
Embolic Agents”, herein incorporated by reference, there
is disclosed a method for introducing liquid embolic
agents/solutions into the human body to form precipitated
embolic occlusion masses, and also how this method is
used for treating hepatic tumors using portal vein
embolism. In U.S. Patent 5,702,361 “Method for
Embolizing Blood Vessels”, herein incorporated by
reference, there is disclosed a method of embolizing a
vascular site in a patient’s blood vessel comprising of
introducing, via a catheter, at the vascular site to be
emobolized a non—particulate agent or a plurality of such
via a catheter, to said vascular
agents, and delivering,
site a polymer composition comprising a biocompatible
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polymer, a biocompatible solvent and contrast agent,
wherein the delivery is conducted under conditions where
the polymer precipitate forms in situ at the vascular
site resulting in the embolizing of the blood vessel and
where the non—particulate agent is encapsulated within
the precipitate. Additional devices applicable to the
present invention are those disclosed in U.S. Patent No.
5,882,334 “Balloon/delivery Catheter Assembly with
Adjustable Balloon Positioning,” incorporated herein by
reference, directed to a catheter assembly for delivering
Further, Inc.,
Irvine, California 92618,
the Rebarm Micro Catheter,
compositions. Micro Therapeutics,
2 Goodyear, markets medical
devices, such as, Equinox“
Occlusion Balloon System and Silverspeedm guidewires,
that are approved by the U.S. Food and Drug
Administration for use in treating conditions such as
those within the present invention.
The compositions of the present invention can
be used advantageously in conjunction with any
embolization method that employs an embolizing agent,
occluding agent, or such composition that creates an
embolic block, or occlusion.
The compositions of the present are used to
particular advantage in conjunction with commercially
available stereotaxic devices which facilitate the
for
precise deposition of the composition, such as,
forming an occlusion within a cavity that is to be
filled,
that is the source of blood supply for a tumor.
or for forming an occlusion in a blood vessel
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Utility
The present invention is useful for filling,
occluding, partially filling or partially occluding an
unfilled volume or space in a mass (“a space”). In
particular, the composition is useful for filling an
existing space, e.g., the lumen of a blood vessel, or the
sac of an aneurysm, a space created by a transiently
placed external device,'e.g., a catheter or like device,
a space created by a procedure, an excision or like
e.g.,
procedure or implantation of an object, a stent or
e.g.,
or a space created by the composition; the
like device,
composition is also useful for adhering tissue to tissue,
or adhering tissue to a device. The composition has the
property of polymerizing when it comes in contact with an
anionic environment, or when it is deployed in situ in an
existing space, e.g., the lumen of a blood vessel, or the
sac of an aneurysm, a space created by a transiently
placed external device, a catheter or like device,
e.g.,
a space created by a procedure, an excision or like
e.g.,
procedure or implantation of an object, a stent or
e.g.,
like device, or a space created by the composition.
The present invention is useful as an embolic
agent that selectively creates an embolic blockage in the
duct, fistula or other like body
lumen of a blood vessel,
passageways.
The present invention can be prepared and
maintained as a monomeric component and second component
until needed. It has the ability to reliably and
predictably change from a liquid state to a solid state,
which is essential for its introduction and controlled
duct, fistula or
placement into the lumen of vessel,
other like body passageways. The composition has low
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viscosity, which is essential for its administration by
syringes and micro—catheters or other like devices.
The cohesive characteristics of the invention
are such that when the composition in administered into
an anionic fluid environment, such as blood, the
composition forms a single aggregate structure.
Additionally, the adhesive characteristics are such that
the composition attaches to the lumen of vessel, duct,
fistula or other like body passageways, but not to the
degree where the device depositing the composition will
become fixed to it before the practitioner can remove it.
The present invention causes mild tissue
inflammation, sufficient to cause scarring, but not so
severe to cause the formation of pus. Scar formation is
desirable as the scar tissue is necessary to maintain the
functionality of the embolic block after the composition
has biodegraded, or otherwise eliminated from the lumen.
The composition is sufficiently stable to biodegradation
to allow for scarring to occur.
The present invention is radiopaque. Although
this characteristic is not necessary for its function as
an embolic agent, radiopacity allows the embolic block to
be observed with x—ray or other such imaging techniques.
The rate of heat released during polymerization
of the present invention is low enough such that the heat
does not adversely effect surrounding tissues that may be
heat sensitive, such as brain tissue.
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The present invention and its biodegradation
products are sufficiently non—histotoxic and non-
cytotoxic so that its presence is well tolerated in the
body.
The composition of the present invention is
useful for filling, occluding, partially filling or
partially occluding an unfilled volume or space in a mass
(“a space”).
The present invention provides a method for
filling, occluding, partially filling or partially
occluding an unfilled volume or space in a mass. The
types of unfilled volumes or spaces within the scope of
the present invention includes, but are not limited to
the following instances.
For example, the present invention is used as a
method of filling, occluding, partially filling or
partially occluding an existing space, such as, a lumen
of a passageway in the body, a blood vessel, a
duct,
e.g.,
or a fistula. Examples of the types
an aneurysm,
treatments covered by this method of use, include but are
not limited to the following. The present invention is
useful as a method of treating arteriovenous
(AVM)
the AVM are occluded thereby cutting off the blood supply
to the AVM.
to ablate diseased or undesired tissue by cutting off the
malformations where the blood vessel(s) that feed
The present invention is useful as a method
In particular, the present
tissue’s blood supply.
invention is useful as a method of treating a tumor
having a discrete blood supply, where the blood vessel(s)
that feed the tumor are occluded thereby cutting off the
blood supply to the tumor resulting in diminished growth
or death of the tumor. The present invention is useful
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as a method of preventing or mitigating the development
of an aneurysm by creating a partial occlusion at a
location in the blood vessel selected to modify the fluid
dynamics within the vessel to mitigate the formation or
development of an aneurysm. The present invention is
useful as a non-surgical method of treating symptomatic
uterine leiomyomas by embolizing/occluding the uterine
artery. This method has been reported using a non alkyl
cyanoacrylate composition in the Journal of Vascular and
Interventional Radiology, 10:89l—894, July-August 1999.
The present invention is useful as a method of
sterilizing a female mammal by occluding the fallopian
tubes thereby preventing the passage of the eggs from the
The use of an occluding agent to
Patent No.
ovaries to the uterus.
sterilize a female mammal is disclosed in U.S.
5,989,580 “Method of Sterilizing Female Mammals,” herein
incorporated by reference. The methods disclosed in this
patent can be advantageously applied using the
compositions of the present invention, and are within the
scope of the present invention.
The present invention is an embolic agent that
provides a method for selectively creating and placing an
embolic blockage which mechanically blocks, totally or
duct, fistula or
partially, the lumen of a blood vessel,
other body passageway. In particular, the current
invention is particularly useful in blocking, totally or
partially, or diverting the flow of blood through the
lumen.
The present invention can be advantageously
used to block blood flow to certain tissues or areas.
the present invention can be used to treat
(AVM).
For example,
arteriovenous malformation An AVM is a collection
of abnormal blood vessels which are neither arteries or
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These vessels are packed closely together to form
Blood flow into the AVM nidus is
veins.
the nidus of the AVM.
through thinned, enlarged, tortuous vessels and is
rapidly shunted into draining veins because the nidus
contains no arterioles or capillaries to provide high
resistance. Clinical symptoms experienced because of
AVMs are bleeding, re—direction of blood from nearby
or seizures.
normal structures, The primary clinical
problem associated with cerebral AVM is the potential for
lethal hemorrhage. The current standard of care for
treating AVMS is surgical removal, high energy radiation
or embolization with particular devices.
Further, the present invention can be used for
treating cancer by diverting or blocking blood flow to
tumors, the present invention is particularly useful for
treating tumors in areas that are not easily accessible
brain tumors.
for surgical intervention, for example,
Other advantageous uses of the present
invention are for aortopulmonary closure; treatment of
artery pseudoaneursym; hepatic artery vascular occlusion
and for temporary vascular occlusion during co-
treatment of other
administration of cytotoxic drugs;
types of vessels, for example, the composition can be
used for creating tubal occlusions, fallopian tube
occlusions, vas deferens occlusions, and urinary
occlusions.
The present invention provides a method of
filling, occluding, partially filling or partially
occluding a space created by a transiently placed
external device, such as, a catheter balloon. Examples
of the types of treatments covered by this method of use
include, but are not limited to the following. The
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present invention is useful as a method of treating an
aneurysm by filling the space within the aneurysm with a
composition of the present invention, where the
composition polymerizes in the space within the aneurysm,
thereby preventing the rupture of the aneurysm. This
treatment can be effected using the present invention
with any number of catheters, catheter coils, catheter
wires or catheter balloons commercially available.
Examples of such devices are commercially available from
For instance, Micro Therapeutics, Inc., 2
California 92618,
the Rebar“ Micro Catheter,
sources .
Goodyear, Irvine, markets a line of
medical devices, such as,
Equinox“ Occlusion Balloon System and Silverspeedm
guidewires. U.S. Patent No. 5,882,334
“Balloon/delivery Catheter Assembly with Adjustable
Similarly,
Balloon Positioning,” assigned to Target Therapeutics,
Inc., and incorporated herein by reference, is directed
to a catheter assembly for delivering compositions, such
as, those of the present invention.
The present invention also provides a method of
filling, occluding, partially filling or partially
occluding a space created or resulting from a procedure,
such as with the excision of tissue, or insufflation.
Examples of the types of treatments covered by this
method of use include, but are not limited to the
following. The present invention is useful as a method
of treating oozing capillaries following an excision
procedure.
The present invention further provides a method
of filling, occluding, partially filling or partially
occluding a space created by the placement or
a medical device.
implantation of an object, such as,
Examples of the types of uses covered by this method of
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use include, but are not limited to the following. The
present invention is useful as a method of restoring the
normal fluid dynamics at the peripheral edges of a
vascular stent by filling the dead spaces between the
stent and the lumen wall created by the implantation of
the stent.
Still another advantageous use is the
controlling and smoothing the blood flow around stents.
A major complication from the balloon angioplasty and the
use of stents is disruption of the smooth flow of blood
past and around the stent which can lead to the formation
of blood clots and their associated complications. The
composition of the present invention can be used to
modify and make regular the slip streams of blood through
and adjacent to the stent to mitigate or alleviate the
cause of the turbulence, and such turbulence causing
states.
The present invention further provides a method
of filling, occluding, partially filling or partially
occluding a space created by the composition itself, such
as, where the composition is used as a bulking agent.
Examples of the types of uses covered by this method of
For
use include, but are not limited to the following.
example, a method of recreating normal external contours,
such as following physical trauma.
Administration
The monomer component and second component of
the present invention are combined just prior to use.
The composition of the present invention is administered
using any type of deployment device. The term
“deployment device” refers to a device used to deploy
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fluids or compositions similar to those of the present
catheter devices, catheter
or the like.
invention, such as, a needle,
balloon, stereotaxic placement devices,
Methods for using these devices are readily known to one
of ordinary skill in the art, and such devices are
commercially available. Such devices and methods are
of ordinary skill in art. For
5,925,683 “Liquid Embolic Agents”,
readily known to those
example in U.S. Patent
herein incorporated by reference, there is disclosed a
method for introducing liquid embolic agents/solutions
into the human body to form precipitated embolic
occlusion masses, and also how this method is used for
treating hepatic tumors using portal vein embolism. In
U.S. Patent 5,702,361 “Method for Embolizing Blood
Vessels”, herein incorporated by reference, there is
disclosed a method of embolizing a vascular site in a
patient’s blood vessel comprising of introducing, via a
catheter, at the vascular site to be emobolized a non-
particulate agent or a plurality of such agents, and
delivering, via a catheter, to said vascular site a
polymer composition comprising a biocompatible polymer, a
biocompatible solvent and contrast agent, wherein the
delivery is conducted under conditions where the polymer
precipitate forms in situ at the vascular site resulting
in the embolizing of the blood vessel and where the non~
particulate agent is encapsulated within the precipitate.
Additional devices applicable to the present invention
5,882,334
“Balloon/delivery Catheter Assembly with Adjustable
are those disclosed in U.S. Patent No.
Balloon Positioning,” incorporated herein by reference,
directed to a catheter assembly for delivering
Further, Micro Therapeutics, Inc.,
Irvine, California 92618,
the Rebarm Micro Catheter,
compositions.
2 Goodyear, markets medical
devices, such as, Equinox“
Occlusion Balloon System and Silverspeedm guidewires,
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that are approved by the U.S. Food and Drug
Administration for use in treating conditions such as
those within the present invention.
The composition of the present invention are
administered with any type of commercially available
catheter devices, or stereotaxic placement
needle,
devices, preferably in conjunction with imaging
technology that provides the practitioner with guidance
as to the placement of the composition. The compositions
of the present invention can be used advantageously in
conjunction with any embolization method that employs an
or such composition
embolizing agent, occluding agent,
that creates an embolic block, or occlusion, or otherwise
in effect is used for filling, occluding, partially
filling or partially occluding an unfilled volume or
space in a mass (“a space").
EXAMPLES
The following examples are given to enable
those of ordinary skill in the art to more clearly
understand and to practice the present invention. The
examples should not be considered as limiting the scope
of the invention, but merely as illustrative and
representative thereof.
EXAMPLE 1
PREPARATION OF 2-HEXYL CYANOACETATE
A 5 liter, 24/40 ground glass jointed flask was
configured with a reflux condenser, Dean—Stark trap, and
The reaction vessel was
(Aldrich
football magnetic stirring bar.
charged with the 1,275.0 g of cyanoacetic acid
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1,581.5 g of 2-hexanol (Aldrich Chemical
and 3.0 g of p-toluenesulfonic acid (Aldrich
and 1,500 of toluene (Aldrich Chemical
Chemical Co.),
Co.)
Chemical Co.),
Co.). The reaction mixture was stirred and heated to
Water was formed as a byproduct of the reaction
The
reflux.
and was collected during the course of the reaction.
reaction was continued until there was a period of over
30 minutes where no water was produced. The amount of
water collected was 230 ml and indicated that the
reaction had completed with a 85.2% theoretical yield.
The reaction mixture was allowed to cool to room
temperature.
The reaction mixture was stirred and 500 ml of
a saturated baking soda (sodium bicarbonate) solution was
The reaction mixture was
The
gradually added to the mixture.
stirred vigorously until the frothing stopped.
reaction mixture was poured into a six liter separatory
funnel, to which an additional 500 ml of water was added.
The aqueous phase
The pH of the
The funnel was vigorously agitated.
was separated and saved as Reaction Water.
aqueous layer was measured to insure that the pH was
Another 500 ml of water was added to the organic
The
over 8.
phase reaction mixture in the separatory funnel.
contents of the funnel were again agitated, the aqueous
and organic phases were allowed to settle, and the
aqueous phase separated and also saved as Reaction Water.
This washing procedure was repeated two additional times.
The organic phase was moved to a 5—liter flask. The
flask was configured with a distillation condenser. The
and the remaining
The
reaction mixture was heated to reflux,
water was separated from the mixture and discarded.
apparatus was reconfigured for vacuum fractional
the toluene and 2-hexanol in
distillation. Initially,
the mixture were removed by reducing the pressure of the
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apparatus to about 5 Torr, and then by heating the
mixture to 60° with stirring. After the solvents were
removed, the pressure was further reduced to less than
1 Torr and gradually increased heat until the desired
2—hexyl cyanoacetate began to distill off. The heat was
adjusted so that the product was recovered at a rate of 2
(70.76%
and was halted when
drops/sec. The recovery collected 1921.1 g
yield)
no more material came out of the distillation unit.
of the 2—hexyl cyanoacetate,
Gas
chromatographic analysis of the purity of the 2—hexyl
cyanoacetate indicated that the product was 98.3% pure,
which was well above 95% purity requirement for
proceeding to the next procedure.
If the purity of the 2—hexyl cyanoacetate had
been below 95%, the material could have be purified by
vacuum distillation, or using any like technique for
purification known to those of ordinary skill in the art.
EXAMPLE 2
PREPARATION OF 2-HEXYL CYANOACRYLATE
A 5—liter three—necked flask was configured
with a reflux condenser, Dean-Stark trap, an addition
funnel and a mechanical stirrer with a glass paddle in a
Paraformaldehyde 272.4 g and
The
5—liter heating mantle.
methanol 1,500 ml were combined in the flask.
reaction mixture was heated to reflux and stirred for a
3 ml
period of 1 hr until the solution began to cleared.
of piperidine was washed into the reaction mixture with
followed by 1521.9 g of
The
methanol, 2—hexyl cyanoacetate
added in a dropwise fashion. resulting reaction was
exothermic, and the heat was adjusted to maintain the
reaction mixture at reflux temperature. The reaction
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mixture was refluxed for an additional 30 minutes after
the conclusion of the addition. Methanol was distilled
from the reaction mixture and collected through the Dean-
(98%)
The reaction
Stark trap until 1420 ml of the original methanol
was recovered (compensating for spillage).
mixture was halted overnight at this point.
The reaction vessel was configured with a
and placed under
The
vacuum apparatus to collect residues,
high vacuum to remove remaining volatile materials.
vacuum was gradually increased until less than 10 Torr
was reached. The apparatus was heated until all the
solvent had been removed. Once the solvent was removed,
75 g of phosphorous pentoxide was added to the mixture
taking care to minimize its exposure to air. The heat
was discontinued, and the mixture was stirred for one
hour. The apparatus was then flooded with sulfur
dioxide. The pressure was reduced to less than 10 Torr
and heated slowly, the flow of sulfur dioxide was
adjusted for a constant low—level flow of gas into the
apparatus.
A 1 liter flask was washed with concentrated
sulfuric acid, three times with water, and once with
ultra pure water. The flask was oven dried for one hour
at 110°C and was allowed to cool to room temperature. 10
drops of 85% phosphoric acid and approximately 25-50 mg
of hydroquinone was added to the 1 liter flask. The
flask was fitted as the receiver flask to the
distillation apparatus. The pressure of the distillation
was reduced to less than 10 Torr. The reaction mixture
was heated and stirred until the distillation began.
418 g of 2—hexyl cyanoacrylate was collected at a 25%
yield. The distillation was halted when the temperature
rose above 110°C.
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EXAMPLE 3
Purification of 2—Hexyl Cyanoacrylate
The 2—hexyl cyanoacrylate was purified in a two
step process. The compound was first by vacuum
5 distillation, and then further purified by spinning band
column.
Vacuum Distillation
A vacuum distillation apparatus was configured
with a 2 L flask, magnetic stirrer, fraction cutter, a
10 10" Vigreux column a clasien head, condenser, thermometer
and a 100 ml forecut receiving flask. 10 drops of 85%
phosphoric acid and 10 mg of hydroquinone was added to
the forecut flask. The unpurified 2—hexyl cyanoacrylate
was place into the distillation flask and the pressure of
15 the unit was reduced to just under 1 Torr. The material
was stirred and gradually heated until product was being
distilled and collected at a rate of one drop per minute.
After 35 ml of distillate was collected, a second 2 L
receiving flask that had been prepared by acid washing,
20 followed by the addition of 25 drops of 85% phosphoric
acid and 20 mg hydroquinone was placed to receive the
distillate. The distillation rate was gradually increase
till the product was being collected at a rate of 2-3
drops per second. When the distillation head temperature
25 rose 2°C above that used to collect the main fraction,
the distillation was completed. Heat was discontinued,
and the material was allow to cool under dry air by air
filtered through a drying tube.
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Spinning Band Column Purification
The spinning band column (B/R Instrument Corp.,
9119 Centreville Road, Easton, Maryland 21601,
Model 9600) is a long jacketed silvered column fitted
with a 30/50 socket joint at the bottom. A magnetic
stirring bar was added to the 5 L socket joint flask,
which was then filled with the product to be purified. A
heating mantle is supported on a magnetic stirrer that is
raised and lowered with a laboratory jack to fit to the
column. On the upper right hand side of the column there
was another 30/50 male socket joint for a 100 ml
All flasks and joints were greased with
When
receiving flask.
high vacuum grease to assure a good vacuum seal.
assembled, a glass temperature probe was inserted into
the 10/15 joint of the flask, and a metal Tempora probe
was inserted inside the glass probe. The 29/42 joint
containing the stopcock was greased and placed into the
flask and connected to a sulfur dioxide gas line. The
pressure of the system was gradually reduced down to just
under 1 Torr of pressure.
Operation of the spinning band column was
controlled by a microprocessor. The column was
programmed to operate under the following conditions, the
water cooling temperature was set to 15°C, the column’s
motor turns on at 24°C, equilibration time was 2 min,
open temperature 28°C, close temperature 90°C, mantle rate
24°C,
90°C.
flow of sulfur dioxide was leaked into the system.
reflux ratio 20 to 1 and pot temperature to end run
Just prior to beginning the distillation a small
The
temperature of the flask was monitored during the
distillation to ensure that the temperature at no time
rose above lOO°C. The distillate was collected in the
receiver flask at the end of the distillation.
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The contents in the flask of the spinning band
column were allowed to cool for 30 min. A second high
vacuum distillation apparatus configured identically to
the vacuum distillation apparatus first used in this
procedure was setup using a 2 L round bottom flask. To
0.0275 g
The
this flask was added 0.0269 g of hydroquinone,
of p—methoxyphenol, and 0.0794 g of phosphoric acid.
residue for pot of the spinning band column was added to
the 2 L round bottom flask of the vacuum distillation
apparatus. The contents of the flask was stirred and the
pressure of the unit was reduced to just less than
1 Torr. A small stream of sulfur dioxide was leaked into
the apparatus as the distillation continued. A receiver
flask was prepared by adding 10 mg hydroquinone and 15
drops of 85% phosphoric acid. A forecut fraction of
86.3 g was collected at the rate of 2-6 drops per minute.
The main fraction was collected in a receiver similarly
prepared as the forecut fraction flask. 1620.1 g of main
fraction product was collected at a rate of 20-25 drops
per minute. The material was then re—distilled by the
spinning band column under the previous conditions.
The purity of the 2—hexyl cyanoacrylate was
determined by gas chromatography. The gas chromatograph
was configured as follows,
HP 5890 Gas Chromatograph with HP Chemstation
Software.
Column Description: Supelco Nukol (60 meter,
I.D.—O.32 mm, film thickness—l micron).
Instrument Parameters: Method 1
Injector Temperature: 220°C
Detector Temperature: 280°C
Head Pressure: 15 PSI
Air Pressure: 35 PS1
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Hydrogen Pressure: 20 PSI
Aux: 60 PSI
Initial Oven Temperature: 140°C for 20 min.
Ramp: 5°C/min.
5 Final Oven Temperature: 200°C for 50 min.
A Splitless System.
Injection Volume: 1.0 micro liter
1.0069 g of the 2—hexyl cyanoacrylate was mixed
thoroughly with 2 drops of 1-hexanol (0.0044 g), was
10 analyzed and impurities were found to be at an acceptable
for use. The 2—hexyl cyanoacrylate was sufficiently pure
to use for product.
EXAMPLE 4
FORMULATION OF THE MONOMER COMPONENT
15 The monomer component was formulated with the
following materials 2—hexyl cyanoacrylate 1249.9 g,
hydroguinone 0.0764 g, p—methoxyphenol 0.0874 g and
phosphoric acid 0.1693 g. The hydroquinone and
p—methoxyphenol were kept under reduced pressure in a
20 dessicator over a drying agent. The pure phosphoric acid
was particularly deliquescent and care was taken not
permit water contamination. The calculated molar
quantities and PPM of each material were as follows,
Material Moles ggm
25 2—hexyl cyanoacrylate 6.8964 999,547
hydroquinone 0.000694 100
p—methoxyphenol 0.000704 102
phosphoric acid 0.001726 250
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Overall purity of the formulation was determined by gas
chromatograph to be less than 1%, using 1—hexanol as an
internal standard.
Instrument Description: HP589O Gas
5 Chromatograph with HP chemstation
software.
Column Description: Supelco Nukol (60 meters-
length,'I.D., 0.32 mm, Film Thickness 1
micron)
10 Instrument Parameters: Method 1
Injector Temperature: 220°C
Detector Temperature: 280°C
Head Pressure: 15 PSI
Air Pressure: 35 PSI
15 Hydrogen Pressure: 40 PSI
Aux.: 60 PSI
Initial Oven Temperature: 140°C for 20 min.
Ramp: 5°C/min.
Final Oven Temperature: 200°C for 50 min.
20 A Splitless System:
Injection Volume: 1.0 microliter
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EXAMPLE 5
PREPARATION OF THE
2-HEXYL CYANOACRYLATE POLYMER COMPONENT
(“the Second Component”)
5 Ethyl myristate was obtained commercially from
1O
15
20
25
30
Aldrich Chemical Company at 97% purity. Prior to use,
the ethyl myristate was further purified by vacuum
distillation to 99.8% purity following standard routine
chemical procedures.
Six 3 ml syringes were fill with purified
2—hexyl cyanoacrylate. 500 mg of sodium bicarbonate and
250 ml of ultra pure water were placed into a Waring
blender. The lid of the blender was adjusted so that the
contents of the syringes could be emptied dropwise into
the center of blender while the blender was stirring.
With the speed of the blender set to high, each of the
syringes were emptied in a dropwise fashion into the
stirring blender. When the addition was completed, the
lid of the blender was closed and the mixture was stirred
for another minute. The solution was decanted from the
blender leaving just solid material in the blender.
Residual solid material that was inadvertently removed
with the decanted solution was recovered by filtration,
washed with ultra pure water and placed back into the
blender.
of the blender was rinsed with ultra pure water back with
An additional 250
Solid material adhering to the inside portion
the rest of the solids in the blender.
ml of ultra pure water was added into the blender, and
the water and solid mixture was blended for 1 minute.
Following the last procedure, water solution was decanted
large coarse fritted glass funnel filter that
The solid
through a
recovered solid material in the solution.
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methanol prior to be added back
to the rest of the solid material. The walls of the
methanol to collect all the
the blender. 250 ml of Methanol
material was washed with
blender were rinsed with
solid material back into
was added to the blender. The solids were blended for
one minute. The solid material is filtered from the
methanol. Any residual solid material in the blender is
washed with methanol and combined with the solid material
filtered from the methanol. The solid material on the
filter was placed under a low vacuum to remove the rest
of the methanol. The solid material was moved
quantitatively to a lOO ml round bottom standard tapered
flask.
remove the remaining methanol.
The flask was placed under reduced pressure to
2 g of the solid material
was combined with 100 g of powdered gold. The mixture
was placed into a standard laboratory blender and blended
for one minute. The blender was agitated constantly
during the blending to ensure that the gold did not
settle during the blending. 1.020 g portions of the
blended material were placed into previously cleaned and
To each bottle was added 500 mg of
The filled bottles were
prepared bottles.
ethyl myristate at 99.8% purity.
kept under a Laminar flow hood. The unsealed bottles
were arranged in trays for immediate ethylene oxide
sterilization by Sharp Coronado Hospital, Sterile
Processing Department under standard conditions.
EXAMPLE 6
COMPARISON OF CATHETHER ADHESION FORCE
FOR 2-HEXYL CYANOACRYLATE (NEURACRYL M) AND
n-BUTYL CYANOACRYLATE (HISTOACRYL) COMPOSITIONS
The present invention is also known by the name
of Neuracryl M, where Neuracryl Ml corresponds to the
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monomer component, and Neuracryl M2 corresponds to the
second component comprising of the gold coated 2—hexyl
acrylate. This example demonstrates differences in
adhesion between the two cyanoacrylates by measuring the
amount of force required to remove a catheter from
various compositions of Neuracryl and Histoacryl.
Histoacryl is commercially available from Braun GmbH. It
is similar to Neuracryl M in that it is a polymer
composition also based on a cyanoacrylate structure,
i.e., n—butyl cyanoacrylate. However, the force required
to withdraw a catheter from Histoacryl is greater than
that required for Neuracryl M, and in this key aspect,
Neuracryl M possesses a surprising and unexpected
advantage over Histoacryl.
The force resulting from catheter adhesion was
determined for Neuracryl M1 and M2 (mixed), pure
Neuracryl Ml, Neuracryl Ml mixed with 33% Ethiodol,
Neuracryl Ml mixed with 50% Ethiodol, pure Histoacryl,
Histoacryl mixed with 33% Ethiodol, and Histoacryl mixed
with 50% Ethiodol were measured and compared.
All the mixtures were injected through a
TurboTracker micro catheter device (Medi—tech/Boston
MA).
immediately prior to use to prevent separation of the
Scientific, Watertown, All mixtures were prepared
components or contamination. The catheter tips were
placed at the bottom of 10 mm deep by 5 mm diameter wells
filled with 0.2 mL of heparinized human whole blood.
Through the micro catheter, 0.15 mL of each embolic
mixture was injected into each well, surrounding the tip
of the micro catheter. Mixtures containing Histoacryl
were allowed to polymerize for 1 minute, and those
containing Neuracryl for 3 minutes. The microcatheters
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were then extracted from the polymerized cyanoacrylates
(Model 1000 Materials
MA)
at a constant speed of 8.3 mm/sec
Testing System; Instron, Canton, and the forces
required for extraction were measured and recorded
25-lb capacity; Interface
Scottsdale, AZ).
(Minibeam Force Transducer,
Advanced Force Measurement, Five
samples of each mixture were tested. Comparison of the
results was performed using the Student t test.
Successful mesurements of the peak forces
required for the extraction of the catheters from the
polymerized cyanoacrylates were obtained for six of the
seven mixtures tested. A wide range of peak forces were
required to extract the microcatheters from the various
mixtures. The force of extraction for the Neuracryl M1
and 50% Ethiodol mixture was less than 0.05 Newtons and
beyond the ability of the apparatus to obtain precise
measurements. The peak forces required to extract the
microcatheters from either Histoacryl mixed with 33%
Ethiodol (1.44 N i 0.33)
(P