U.S. patent application number 13/616947 was filed with the patent office on 2013-01-10 for cyanoacrylate adhesive compositions, methods of sterilization of the compositions, and articles of manufacture containing such compositions.
This patent application is currently assigned to CHEMENCE MEDICAL, INC.. Invention is credited to Carlos R. Morales.
Application Number | 20130011589 13/616947 |
Document ID | / |
Family ID | 36074206 |
Filed Date | 2013-01-10 |
United States Patent
Application |
20130011589 |
Kind Code |
A1 |
Morales; Carlos R. |
January 10, 2013 |
Cyanoacrylate Adhesive Compositions, Methods of Sterilization of
the Compositions, and Articles of Manufacture Containing Such
Compositions
Abstract
The viscosities of 2-cyanoacrylate adhesive compositions are
adjusted by the addition of polymeric thickeners to a preferred
initial viscosity that will not increase significantly when
sterilized by heating them at a temperature of no greater than
about 110.degree. C. for no more than about 120 minutes. Articles
of manufacture are vials or squeezable tubes containing these
compositions.
Inventors: |
Morales; Carlos R.;
(Cumming, GA) |
Assignee: |
CHEMENCE MEDICAL, INC.
Alpharetta
GA
|
Family ID: |
36074206 |
Appl. No.: |
13/616947 |
Filed: |
September 14, 2012 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
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13358690 |
Jan 26, 2012 |
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13616947 |
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10944635 |
Sep 17, 2004 |
8110144 |
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13358690 |
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Current U.S.
Class: |
428/34.4 ;
428/35.7; 524/555 |
Current CPC
Class: |
A61L 2/04 20130101; Y10T
428/1352 20150115; Y10T 428/13 20150115; Y10T 428/131 20150115;
C09J 4/06 20130101; C12Q 1/22 20130101; A61L 2/28 20130101 |
Class at
Publication: |
428/34.4 ;
524/555; 428/35.7 |
International
Class: |
C09J 133/14 20060101
C09J133/14 |
Claims
1. A cyanoacrylate adhesive composition, comprising: at least one
2-cyanoacrylate monomer; and at least one polymeric thickener in an
amount establishing an initial viscosity that will not
significantly increase when the composition is sterilized at a
temperature no greater than approximately 110.degree. C. for a
period of time sufficient to sterilize the composition.
2. The composition of claim 1, in which: said initial viscosity is
in the range of about 400 to about 600 centipoises.
3. The composition of claim 1, in which: said period of time is no
greater than about 120 minutes.
4. An article of manufacture, comprising: a container packed with a
mixture of at least one 2-cyanoacrylate monomer; and at least one
polymeric thickener in an amount establishing a viscosity that will
not significantly increase when the mixture is sterilized; the
container then being sealed; and heated to a temperature of between
about 100.degree. C. and about 110.degree. C. for a period of time
between about 60 minutes and about 120 minutes.
5. An article of manufacture, comprising: a container comprised of
a material taken from the list of: (a) aluminum, (b) plastic, and
(c) glass; packed with a mixture of about 3.5% by weight of
polyoctyl-2-cyanoacrylate, about 100 ppm sulfur dioxide, and about
1000 ppm butylated hydroxyanisole (BHA), all dissolved in the
balance percentage by weight of octyl-2-cyanoacrylate monomer, then
sealed; and the sealed container heated to a temperature of between
about 100.degree. C. and about 110.degree. C. for a period of time
between about 60 minutes and 120 minutes, establishing a sterile
adhesive having a viscosity of in the range of about 400
centipoises to about 600 centipoises.
Description
PRIORITY CLAIM
[0001] This U.S. application for utility patent is a divisional of
U.S. patent application Ser. No. 13/358,690 filed Jan. 26, 2012,
which is a divisional of U.S. patent application Ser. No.
10/944,635 filed Sep. 17, 2004, now U.S. Pat. No. 8,110,144,
granted Feb. 7, 2012.
BACKGROUND OF THE INVENTION
[0002] 1. Field of the Invention
[0003] The invention relates to compositions of cyanoacrylate
monomer and polymer adhesive compositions, a process for
sterilizing them for application in the medical and veterinary
fields, and a method of assaying the sterilization of cyanoacrylate
compositions.
[0004] 2. Background
[0005] It is known to use 2-cyanoacrylate esters as adhesives for
bonding tissue in medical or surgical procedures performed upon the
human or animal body. 2-cyanoacrylate esters polymerize rapidly,
and often instantaneously, upon contact with tissue or body fluid.
In these applications, the adhesive composition can be used to
close wounds, as well as for covering and protecting surface
injuries such as lacerations, abrasions, burns, sores and other
open surface wounds. To be used in medical and veterinary fields,
2-cyanoacrylates must be sterilized. This is generally done in
sealed containers to provide sterility, and from a practical
perspective, to protect the compositions from moisture and
premature polymerization. Previous sterilization methods involved
either the use of ionizing radiation, including e-beam and gamma
ray irradiation, dry heat at elevated temperatures (160.degree.
C.), or chemical sterilization such as with ethylene oxide.
[0006] When an adhesive composition is applied to a surface to be
closed or protected, it is usually in its monomeric form, and the
resultant polymerization produces the desired adhesive bond.
However, at ordinary temperatures, the monomeric form of the
adhesive has a low viscosity which results in the adhesive
spreading into undesired areas. Therefore, it is desirable to
increase the viscosity of the composition to prevent this unwanted
flow. In order to achieve an increased viscosity, thickening agents
can be added to the monomeric composition.
[0007] The previous methods of sterilization are undesirable in
that the high temperatures required for the previous dry heat
sterilization processes or irradiation could cause premature
polymerization of the monomers. In addition, many polymers that
could be used as thickeners underwent degradation resulting in loss
of viscosity when exposed to typical dry heat conditions of
160.degree. C. This significantly limits the formulators ability to
formulate adhesive compositions which have the desirable stability
and flow characteristics, and which can be sterilized.
BRIEF SUMMARY OF THE INVENTION
[0008] The present invention is directed to a method of sterilizing
2-cyanoacrylate compositions, including heating the composition in
a device at a temperature of from about 70.degree. C. to about
140.degree. C. for an effective amount of time. In another aspect,
the invention includes sterilized 2-cyanoacrylate ester
compositions for use in medicine or surgery, the compositions being
disposed in sealed aluminum containers and being sterilized at a
temperature of between about 70.degree. C. and about 140.degree. C.
The compositions can be disposed in sealed aluminum, tin, stainless
steel tubes or pouches or glass containers. Preferably, the
2-cyanoacrylate compositions are adjusted to an initial viscosity
of 400 to 600 centipoises by the addition of polycyanoacrylate
thickeners, and are sterilized in a preferred method by heating
them at a temperature of no greater than about 110.degree. C. for
no more than about 120 minutes. Articles of manufacture are vials
or squeezable tubes made of compatible glass, aluminum, or
plastic.
[0009] In yet another aspect, the invention is directed to a method
for assaying the sterilization of cyanoacrylate compositions.
DETAILED DESCRIPTION OF THE INVENTION
[0010] As embodied and described herein, the present invention
provides a novel method of sterilizing 2-cyanoacrylate ester
compositions using a combination of chemical and heating means, and
the resulting novel compositions. The combination of monomeric
2-cyanoacrylate, heat and time have a lethal effect on microbials,
rendering sterilized compositions when the appropriate
sterilization condition is achieved and when the method is applied
to 2-cyanoacrylates in sealed containers.
[0011] As used herein, the following terms have the following
meanings:
[0012] The term "cyanoacrylate adhesive composition" or
"cyanoacrylate adhesive compositions" refers to polymerizable
formulations comprising polymerizable cyanoacrylate ester monomers.
The term aldose is intended to refer to both common disaccharides
and monosaccharides.
[0013] In the method of the invention, 2-cyanoacrylate adhesive
compositions are sterilized through an unexpected and heretofore
unknown combination of heat and time, sterilizing at temperatures
significantly lower than previously thought to be effective.
Previous dry heat sterilization methods have required temperatures
of at least 160.degree. C. to 180.degree. C. Heating times at these
temperatures were from 2 hours at 160.degree. C. to 30 minutes at
180.degree. C. Under the present invention, the 2-cyanoacrylate
adhesive compositions can be sterilized at temperatures from about
70.degree. C. to about 140.degree. C. As would be expected, the
time required to effect sterilization will vary depending on the
temperature selected to accomplish the sterilization. At
140.degree. C., sterilization requires approximately 30 minutes. At
70.degree. C., sterilization requires about 600 minutes. Required
heating times for intermediate temperatures are reported in Tables
2 and 3. Ultimately sterilization times for any composition can be
readily determined by one skilled in the art by standard test
methods without undue experimentation.
[0014] Typical sterilization times are listed in Table 1.
TABLE-US-00001 TABLE #1 sterilization heating times 70.degree. C.
600 minutes 80.degree. C. 480 minutes 90.degree. C. 300 minutes
100.degree. C. 120 minutes 110.degree. C. 90 minutes 120.degree. C.
60 minutes 130.degree. C. 60 minutes 140.degree. C. 30 minutes
[0015] According to the assay method of the invention,
sterilization of cyanoacrylate compositions can be assayed for the
effectiveness of a given temperature and sterilization time.
Samples containing formulated n-butyl cyanoacrylate and 2-octyl
cyanoacrylate in sealed borosilicate glass and aluminum tubes were
inoculated with Bacillus subtilis lyophilized spores at a
concentration of 1.times.10.sup.+6 per ml of formulation. In other
embodiments, spores can be introduced into the cyanocrylate
adhesive compositions prior to sterilization using commercially
available biological indicators or spore test strips. Among the
commercially available biological indicators which may be used are:
bacterial spores on a stainless steel disc, bacterial spores on a
steel wire, bacterial spores on steel coupons, bacterial spores on
borosilicate paper and bacterial spores on woven cotton threads.
Among the species of spores which may be chosen for use in the
commercially available biological indicators are Bacillus subtilis
and Geobacillus stearothermophilus. Commercially available
biological indicators may be obtained from any commercial supplier,
such as Raven Labs. Some inoculated glass vials and tubes samples
were kept at room temperature without sterilization as positive
controls, while the rest of the samples were sterilized at
temperatures ranging from 70 to 140.degree. C. with different time
exposures. Samples were sent to a microbiology laboratory for
determination of the presence or absence of growth after the
sterilization procedure was completed to assay the effectiveness of
the process conditions.
[0016] In accordance with the present invention it is preferred to
utilize microorganisms which may be killed by the sterilization
process but which show significant resistance to this process. The
term microorganism refers to bacteria, fungi, yeast, protozoa
algae, viruses and protozoa. Bacterial spores are very resistant to
heat and chemicals; more so than vegetative bacterial cells,
therefore the spores are often used to monitor sterilization
procedures. A preferred organism for monitoring dry heat
sterilization is Bacillus subtilis.
[0017] The spores represent a resting stage in the life cycle of
the Bacillus genus. The resting spore contains a large number of
active enzymes which allow the transformation from dormant cell to
vegetative cell. The germination process, or the return to the
vegetative state, has been described as a time-ordered sequence
involving activation, triggering, initiation and outgrowth.
Activation is reversible and involves an increase in the rate and
extent of germination. Triggering is irreversible and is the result
of spore contact with the germinant. Initiation involves the loss
of heat resistance, release of dipicolinic acid and calcium, loss
of refractility and absorbance. Outgrowth results in formation of
the vegetative cell.
[0018] In accordance with the present invention a cyanoacrylate
composition test sample comprising at least one sterility test
strip, or lyophilized spores is utilized. While reference is made
to "spores" as a test microorganism it should be understood that
microorganisms other than spore formers may be used in conjunction
with the present invention. The spore strips utilized with the
present invention are preferably constructed of materials which are
inert to the microorganisms and inert to cyanoacrylate monomer. A
variety of commercial spore strips is readily available and can be
utilized with the present invention. The spore strips can contain
more than one type of microorganism.
[0019] To assay the sterilized samples and controls, the
compositions including the biological indicators are transferred
into containers filled with an aqueous aldose solution, shaken, and
transferred into a quantity of nutrient medium in an aseptic
container. Transferring the samples to an aldose solution serves to
emulsify the cyanoacrylate monomer without causing it to polymerize
as it would upon exposure to water alone. Aldoses which act to
emulsify the cyanoacrylate include without limitation, dextrose,
lactose, arabinose, mannose, galactose, rhamnose, fructose, sucrose
and glucose. In one embodiment of the invention, the aldose is
dextrose. The concentration of the aldose solution may be from
about 2% to about 50% on a weight/weight basis. A preferred range
for the concentration of the aldose solution is from about 3% to
about 15%. A more preferred aldose concentration is from about 5%
to about 10% weight/weight. The nutrient medium supports the
germination of spores and growth of any viable microorganisms. The
nutrient medium contains a protein substrate for the proteases
liberated during spore germination and during subsequent microbial
growth. The nutrient medium preferably comprises an aqueous
solution or suspension of nutrient components (including the
protein substrate) needed in order to promote the growth of viable
microorganisms that may exist after the sterilization process. One
example of a suitable culture medium is a protein-containing
microbiological broth such as tryptic soy broth (TSB) and/or TSB
with specific protein additives, such as, for example, casein.
Formulations for culture media are well-known to those in the
art.
[0020] The mixture of microorganisms, cyanoacrylate, aldose and
nutrient medium are then sealed within a containing means. The
samples are then incubated for a predetermined period of time at
from about 28.degree. C. to about 37.degree. C. Any microorganisms
not killed during the sterilization process begin to germinate and
grow during the incubation period. In a preferred embodiment the
microorganisms are incubated for at least about seven days.
Thereafter the sample is examined to detect the presence of growth
by different methods, such as visual examination of the samples
followed by microscope Gram stain examination, addition of an
enzymatic indicator such as tetrazolium salts followed by UV
spectrophotometric analysis, or direct UV spectrophotometric
analysis of incubated samples. In one embodiment, after visual
examination a gram stain smear is prepared to look for gram
positive rods which would confirm growth. In another embodiment,
growth can be determined by the addition of enzymatic biological
indicator such as tetrazolium salts, wherein bacterial activity is
determined by development of color which may be measured
quantitatively with an ultraviolet spectrophotometer at 257 nm. In
yet another embodiment, a sample without enzymatic indicator is
analyzed under a spectrophotometer at a wavelength of 480 nm to
determine growth.
[0021] The method of the invention can be applied in principle to
any 2-cyanoacrylate ester monomer. The 2-cyanoacrylate is
preferably an aliphatic cyanoacrylate ester and preferably an
alkyl, cycloalkyl, alkenyl, alkoxyalkyl, fluoroalkyl, fluorocyclic
alkyl or fluoroalkoxy 2-cyanoacrylate ester. The alkyl group may
contain from 2 to 12 carbon atoms, and is preferably a C.sub.2 to
C.sub.8 alkyl ester, and is most preferably a C.sub.4 to C.sub.8
alkyl ester. Suitable 2-cyanoacrylate esters include without
limitation, the ethyl, n-propyl, iso-propyl, n-butyl, pentyl,
hexyl, cyclohexyl, heptyl, n-octyl, 2-ethylhexyl, 2-methoxyethyl
and 2-ethoxyethyl esters. Any of these 2-cyanoacrylate monomers may
be used alone, or they may be used in mixtures.
[0022] The 2-cyanoacrylate monomers of the invention can be
prepared by any of the methods known in the art. U.S. Pat. Nos.
2,721,858, 3,254,111 and 4,364,876, each of which is hereby
incorporated in its entirety by reference, disclose methods for
preparing 2-cyanoacrylates. For example, cyanoacrylates for the
instant invention were prepared by reacting cyanoacetate with
formaldehyde in the presence of heat and a basic condensation
catalyst to give a low molecular weight polymer. A depolymerization
step followed under heat and vacuum in the presence of acidic and
anionic inhibitors, yielding a crude monomer that could be
distilled under vacuum and in the presence of radical and acidic
inhibitors. The distilled 2-cyanoacrylate monomers are then
formulated with radical and acidic inhibitors depending upon their
application and to provide the necessary stability.
[0023] The 2-cyanoacrylate compositions of the invention may in
some embodiments contain a thickening agent to increase the
viscosity of the composition. This thickening agent may be a
polymer. The thickening agent may be selected from the group
consisting of without limitation, poly alkyl-2-cyanoacrylates, poly
cycloalkyl-2-cyanoacrylates, poly fluoroalkyl-2-cyanoacrylates,
poly fluorocycloalkyl-2-cyanoacrylates, poly
alkoxyalkyl-2-cyanoacrylates, poly
alkoxycycloalkyl-2-cyanoacrylates, poly
fluoroalkoxyalkyl-2-cyanoacrylates,
polyalkoxycyclofluoroalkyl-2-cyanoacrylates, poly vinyl acetate,
poly lactic acid and poly glycolic acid. In order to obtain optimum
solubility of the polymer in the monomer, the polymer is often
chosen to be a polymer of the monomer or one of the monomers which
comprise the 2-cyanoacrylate composition. Preferably, the polymer
is soluble in the monomer composition at ambient temperature.
Preferred polymers include polymers of octyl 2-cyanoacrylate, vinyl
acetate lactic acid, or glycolic acid. The preferred weight average
molecular weight of the polymers is from about 300,000 to about
2,000,000. More preferably, the polymer molecular weight is from
about 500,000 to about 1,600,000.
[0024] Cyanoacrylate polymers of the invention can be prepared by
slow addition of the monomer to a mixer containing 0.1% bicarbonate
deionized water. Water is then decanted away, and the polymer is
rinsed several times with deionized water and decanted again.
Following steps include neutralizing the polymer with 0.1 N HCl,
rinsing with deionized water, drying on a vacuum heated oven at
temperature of less than 80.degree. C. and grinding the polymer to
fine particles.
[0025] The amount of thickening agent that is added to the monomer
composition is dependent upon the molecular weight of the polymer
and the desired viscosity for the adhesive composition. The
thickening agent typically is added at from about 1% to about 25%
by weight of the composition. Preferably it is added at from about
1% to about 10%. More preferably it is added at from about 1% to
about 5%. A typical viscosity of the composition is from about 25
to about 3000 centipoises, as measured by a Brookfield viscometer
at 25.degree. C. Preferably, the viscosity is between from about 50
to 600 centipoises at 25.degree. C. The specific amount of a given
thickening agent to be added can be determined by one of ordinary
skill in the art without undue experimentation.
[0026] The 2-cyanoacrylate compositions may contain one or more
acidic inhibitors in the range from 1 to 1,000 ppm. Such acidic
inhibitors include without limitation: sulfur dioxide, nitrogen
oxide, boron oxide, phosphoric acid, ortho, meta, or
para-phosphoric acid, acetic acid, benzoic acid, cyanoacetic acid,
tri-fluoroacetic acid, tribromoacetic acid, trichloroacetic acid,
boron trifluoride, hydrogen fluoride, perchloric acid, hydrochloric
acid, hydrobromic acid, sulfonic acid, fluorosulfonic acid,
chlorosulfonic acid, sulfuric acid, and toluenesulfonic acid.
[0027] The 2-cyanoacrylate compositions may contain one or more
free radical polymerization inhibitors in the range from 0 to
10,000 ppm. Examples such radical inhibitors include, without
limitation, catechol, hydroquinone, hydroquinone monomethyl ether
and hindered phenols such as butylated hydroxyanisol, butylated
hydroxytoluene (2,6-di-tert-butyl butylphenol and 4methoxyphenol),
4-ethoxyphenol, 3 methoxyphenol, 2-tert-butyl-4 methoxyphenol, and
2,2 methylene-bis-(4-methyl-6-tert-butylphenol).
[0028] The 2-cyanoacrylate compositions may contain single or
mixtures of plasticizers such as tributyl acetyl citrate, dimethyl
sebacate, diethyl sebacate, try-ethyl phosphate,
tri-(2ethylhexyl)phosphate, tri-cresyl phosphate, glyceryl
triacetate, glyceryl tributyrate, dioctyl adipate, isopropyl
myristate, butyl stearate, trioctyl trimellitate, and dioctyl
glutarate. The plasticizers may be added to the compositions in
proportions of less than 50% w/w of the formulation.
[0029] The 2-cyanoacrylate compositions may contain small amounts
of dyes like the derivatives of anthracene and other complex
structures. Some of these dyes include, without limitation,
1-hydroxy-4-[4-methylphenylamino]-9,10 anthracenedione (D&C
violet No. 2), disodium salt of
6-hydroxy-5-[(4-sulfophenyl)axo]-2-naphthalene-sulfonic acid
(FD&C Yellow No. 6,),
9-(o-carboxyphenyl)-6-hydroxy-2,4,5,7-tetraiodo-3H-xanthen-3-one
disodium salt monohydrate (FD&C Red No. 3),
2-(1,3dihydro-3-oxo-5-sulfo-2-indole-2-ylidine)-2,3-dihydro-3-oxo-1H-indo-
le-5-sulfonic acid disodium salt (FD&C Blue No. 2), and
[phthalocyaninato (2)] copper added in proportions of less than
50,000 ppm.
[0030] The sterilized cyanoacrylate adhesive compositions of the
invention may be packaged in a container made of any suitable
material. Suitable materials must be heat stable and resistant up
to the sterilization temperature, must provide an adequate barrier
to atmospheric moisture and be compatible with the cyanoacrylate
monomer or monomers. Materials meeting these requirements include
metals and borosilicate type I glass. Suitable metals can include
without limitation aluminum, tin, and stainless steel. Metals can
have different forms like pouches and tubes. Glass can be used as
vials, breakable tubes or any other shape, and contained inside
tubes made out of the same material, or combinations or materials
including plastics. Particularly preferred materials are aluminum
and type I glass. Preferred aluminum tubes comprise a nozzle which
is hermetically sealed by a pierceable membrane of aluminum and are
filled at their end remote from the nozzle prior to closure of the
open end by tight crimping. The glass vials used in this invention,
are made out of borosilicate type I glass and sealed with a
threaded phenolic cap with a silicone/Teflon septum or sealed with
an aluminum crimp cap and a silicone/Teflon septum. In the result,
therefore, preferred embodiments of the invention reside in a
substantially hermetically sealed aluminum container, e.g. an
aluminum tube, containing a sterile 2-cyanoacrylate composition or
type I glass vials hermetically sealed with a phenolic threaded cap
and a silicone/Teflon septum.
EXAMPLES
Example 1
Sample Testing: (Sterility Test Method for all Samples)
[0031] The method was tested by first performing the USP
bacteriostasis and fungi stasis test on glass vials and aluminum
tubes. The sterility test was performed by obtaining spores of
Bacillus subtilis var. niger suspended in irrigation water at a
concentration of 2.3.times.10.sup.+8/ml. Aliquots of 0.48 ml of
these spores were placed in glass serum bottles, lyophilized and
then reconstituted with 50 ml of n-butyl or 2-octylcyanoacrylate
compositions to obtain a volume of 50 ml of inoculated spore
solution with a concentration of 2.times.10.sup.+6/ml. These
cyanoacrylate spore solutions were used to fill the tubes and vials
for the sterilization trials at different temperatures and time and
for the non-sterilized (standard biological indicators) control
vials and tubes. Each tube and vial was filled with a volume of 0.5
to 0.6 ml of a cyanoacrylate composition that rendered a spore
concentration of 2.times.10.sup.+6/ml. Non-sterilized biological
indicators and sterilized spores inoculated samples at different
temperatures and time were transferred to a 5% dextrose USP
solution, shaken and transferred to soy casein digested broth
(SCDB) and incubated at 35-37.degree. C. for at least seven days. A
vial of lyophilized spores with no cyanoacrylate was tested for
population verification. The vial was transferred to sterile
purified water and vortexed for 10 minutes. Serial dilutions of
10.sup.+4, 10.sup.+5, and 10.sup.+6 were plated in duplicate using
soy casein digested broth (SCDB) and incubated for 48 hours at
35-37.degree. C. The 10.sup.+6 dilution yielded duplicate plates in
the countable range. The final calculations showed there were
6.1.times.10.sup.+6 CFU/ml, or 3.1.times.10.sup.+7 CFU/vial.
Polymer Preparation: (Polymer Method for Samples Containing
Polymer)
[0032] 2-OCA polymer was made by adding drop by drop 30 grams of
2-OCA monomer to a blender containing 1000 ml of 0.1% sodium
bicarbonate deionized water while swirling. Bicarbonate water with
the polymer was vacuum filtered on a Kitasato with a Fisherbrand
#Q5 quantitative filter paper, rinsed five times with 500 ml
aliquots of deionized water and decanted. The polymer was
neutralized with 500 ml of 0.1 N hydrochloric acid. The neutralized
polymer was rinsed with three aliquots of 500 ml, decanted, dried
in a vacuum oven at 80.degree. C., and after drying was finely
ground with a mixer.
Sample Composition Preparation:
[0033] The sample of 2-OCA containing polymer was made by mixing
2-octyl cyanoacrylate (stabilized with 100 ppm of SO.sub.2, 1000
ppm of butylated hydroxyanisole) with 3.5% of 2-OCA polymer. The
polymer was dissolved in the formulated 2-OCA by heating and mixing
in a round glass flask equipped with a paddle shaft and mixer at a
temperature no higher than 80.degree. C. and obtaining a viscosity
of 567 cp (measured with a Brookfield DV-II at 25.degree. C.).
Then, the composition was inoculated with lyophilized Bacillus
subtilis spores to produce a minimum concentration of
1.times.10.sup.+6 which were filled in aluminum tubes and glass
type I glass threaded vials. Tubes were sealed by crimping with a
Kentex automatic tubes filler and sealer. The glass vials were
filled with an Eppendorf automatic pipette and sealed with threaded
phenol caps and silicone/Teflon septa. Some inoculated glass and
tube samples were not sterilized and were used as positive standard
biological indicators to indicate livable spores. The rest of the
inoculated and sealed tubes and vials were exposed to the
experimental temperatures and time stipulated in the sterilization
testing protocol conditions.
Tables #2-3 shows example results.
TABLE-US-00002 TABLE #2 2-OCA sterilization example packed in glass
vials with pre-sterilization viscosity of 567 cp Sterilization Type
of Incubation Number Number of Sterilization time Media temperature
samples days of Number of Viscosity @ .degree. C. minutes 400 ml
.degree. C. tested incubated positives 25.degree. C. sterile 90 240
SCDB 30-35 3 7 1 566 100 120 SCDB 30-35 3 7 0 569 100 180 SCDB
30-35 3 7 0 562 110 60 SCDB 30-35 3 7 0 526 110 120 SCDB 30-35 3 7
0 452 120 60 SCDB 30-35 3 7 0 418 120 90 SCDB 30-35 3 7 0 N/A 130
60 SCDB 30-35 3 7 0 343 130 120 SCDB 30-35 3 7 0 N/A 140 30 SCDB
30-35 3 7 0 110 140 45 SCDB 30-35 3 7 0 N/A
Table #2 above shows minimum sterilization temperatures, incubation
temperature, incubation time and the results obtained for samples
of Bacillus subtilis spores inoculated 2-OCA containing 3.5% 2-OCA
polymer (567 cp), 100 ppm SO.sub.2 and 1000 ppm BHA.
TABLE-US-00003 TABLE #3 2-OCA sterilization example packed in
aluminum tubes with pre-sterilization viscosity of 567 cp
Sterilization Type of Incubation Number Number of Sterilization
time Media temperature samples days of Number of Viscosity @
.degree. C. minutes 400 ml .degree. C. tested incubated positives
25.degree. C. sterile 90 240 SCDB 30-35 3 7 2 565 100 120 SCDB
30-35 3 7 0 566 100 180 SCDB 30-35 3 7 0 570 110 60 SCDB 30-35 3 7
0 526 110 120 SCDB 30-35 3 7 0 435 120 60 SCDB 30-35 3 7 0 405 120
90 SCDB 30-35 3 7 0 N/A 130 60 SCDB 30-35 3 7 0 351 130 120 SCDB
30-35 3 7 0 N/A 140 30 SCDB 30-35 3 7 0 102 140 45 SCDB 30-35 3 7 0
N/A
Table #3 above shows minimum sterilization temperatures, incubation
temperature, incubation time and the results obtained for samples
of Bacillus subtilis spores inoculated 2-OCA containing 3.5% 2-OCA
polymer (567 cp), 100 ppm SO.sub.2 and 1000 ppm BHA. Note the sharp
drop in the viscosities of the compositions tested and shown in
Tables 2 and 3 as temperature passes 110.degree. C. The average
viscosity drop from the base viscosity (567 cp) in the last column
in each table going from row 4 to row 5 is 14.45%.
Example II
Sample Composition Preparation
Sample IIA:
[0034] A sample of n-butyl cyanoacrylate (n-BCA) with a viscosity
of 2.8 cp (measured with a Brookfield DV-II at 25.degree. C.)
containing 100 ppm of SO.sub.2 and 1000 ppm of butylated
hydroxyanisole (BHA) was prepared for this example. Then, the
composition was inoculated with biological indicator standards such
as borosilicate spore discs, cotton threads and spore wires with a
spore concentration of 1.times.10.sup.+6 Geobacillus
stearothermophilus. The spore inoculated composition was filled in
type I glass threaded vials with an Eppendorf automatic pipette and
sealed with threaded phenol caps and silicone/Teflon septa. Some
inoculated glass vials were not sterilized and were used as
positive standard biological indicators to indicate livable spores.
The rest of the inoculated sealed vials were exposed to the
experimental temperatures and times stipulated in the sterilization
testing protocol conditions.
Table #4 shows example results.
TABLE-US-00004 TABLE #4 n-BCA monomer sterilization example in
glass vials with pre-sterilization viscosity of 2.8 cp
Sterilization Type of Incubation Number Number of Sterilization
time Media temperature samples days of Number of Viscosity @
100.degree. C. minutes 400 ml .degree. C. tested incubated
positives 25.degree. C. sterile borosilicate 240 SCDB 55-60 3 7 0
2.9 disc Cotton 240 SCDB 55-60 3 7 0 2.8 threads SS wires 240 SCDB
55-60 3 7 0 2.8 Positive NO SCDB 55-60 3 2 3 2.8 control
borosilicate disc Positive NO SCDB 55-60 3 2 3 2.9 Control cotton
threads SS wires NO SCDB 55-60 3 2 3 2.8
Table #4 above shows sterilization temperatures, incubation
temperature, incubation time and the results obtained for samples
of Geobacillus stearothermophilus spores inoculated n-BCA
containing, 100 ppm SO.sub.2 and 1000 ppm BHA.
Sample IIB:
[0035] A sample of n-butyl cyanoacrylate (n-BCA) with a viscosity
of 2.8 cp (measured with a Brookfield DV-II at 25.degree. C.)
containing 100 ppm of SO.sub.2 and 1000 ppm of butylated
hydroxyanisole (BHA) was prepared for this example. Then, the
composition was inoculated with biological indicator standards
cotton threads with a spore concentration of 1.times.10.sup.+6
Bacillus subtilis. The spore inoculated composition was filled in
type I glass threaded vials with an Eppendorf automatic pipette and
sealed with threaded phenol caps and silicone/Teflon septa. Some
inoculated glass vials were not sterilized and were used as
positive standard biological indicators to indicate livable spores.
The rest of the inoculated sealed vials were exposed to the
experimental temperatures and times stipulated in the sterilization
testing protocol conditions.
Tables #5 shows example results.
TABLE-US-00005 TABLE #5 n-BCA monomer sterilization example in
glass vials with pre-sterilization viscosity of 2.8 cp
Sterilization Type of Incubation Number Number of Sterilization
time Media temperature samples days of Number of Viscosity @
100.degree. C. minutes 400 ml .degree. C. tested incubated
positives 25.degree. C. sterile Cotton 240 SCDB 55-60 3 7 1 2.8
threads Positive NO SCDB 55-60 3 2 3 2.8 Control cotton threads
Table #5 above shows sterilization temperatures, incubation
temperature, incubation time and the results obtained for samples
of Bacillus subtilis spores inoculated n-BCA containing 100 ppm
SO.sub.2 and 1000 ppm BHA.
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