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The invention relates to a medical glove such as a surgeon's or examination
glove which contains an antimicrobial inner layer.
BACKGROUND OF THE INVENTION
Typically, several steps are required to insure that surgeon's gloves are
free of bacteria or other microorganisms during surgery. Prior to donning
the gloves, the surgeon must scrub his hands thoroughly with a strong
bactericidal soap and a brush or sponge in an attempt to eliminate or
drastically reduce inimical microorganisms from his hands. Using sterile
techniques, he dons surgeon's gloves which have been presterilized in the
package. Assuming the steps are strictly adhered to, the surgeon's gloves
do not convey bacteria into the wound site. However, after the most
rigorously maintained sequence of scrubbing and proper donning, the
surgeon's hand quickly becomes covered with bacteria inside of the sterile
gloves. The bacteria are present deep in the pores of the skin and cannot
be removed by scrubbing. After the hands are scrubbed and gloves are
donned, bacteria percolate out of the pores and quickly reinfest the
hands. Although these bacteria seldom present any hazard to the surgeon,
they can create a hazard to the patient being operated on if the integrity
of the glove is compromised. Sometimes the gloves will have a pinhole from
time of manufacture, or the gloves are snagged during donning, or the
gloves are punctured by an instrument or a bone fragment. Because the
hands perspire inside the gloves, a reservoir of bacteria laden liquid is
usually present and is easily transferred through any rupture of the
rubber film into the wound site. Conversely, infected fluids from the
patient can transfer through a damaged glove onto the surgeon's hands.
Strong germicides cannot be residual on the hands when the gloves are
donned because they often irritate or sensitize the surgeon's hands.
SUMMARY OF THE INVENTION
The invention provides a medical glove comprising an outer elastomeric body
in the shape of a hand, said glove having an inner coating that contains
an antimicrobial agent, said inner coating being capable of slowly
releasing said antimicrobial agent in an amount and over a period of time
sufficient to maintain an essentially germ-free bacteria-free and
fungus-free environment within said glove after the glove has been donned.
A principal object of the invention is to provide a surgical glove which
provides greater safety to the patient and to the surgeon than
contemporary gloves.
The surgeon's glove of the invention comprises an outer glove body, as
worn, with an inner layer containing an antimicrobial material.
A feature of the antimicrobial containing inner layer is the permeability
of the layer to perspiration to allow transport of the antimicrobial to
microbes on the hand.
Another feature of the bound antimicrobial is the lower tendency to
sensitize or irritate the hands as a result of slow migration of the
active agent from the inner layer to the hand.
Another feature of the antimicrobial containing inner layer is one of
economics. The active agents are expensive, and because the inner layer is
a minor portion of the glove, the glove of this invention is more
economical than it would be if the active agents were incorporated in the
entire glove.
A further feature of the invention is the option of allowing the
antimicrobial to be applied to the inside of the glove or to both the
inside and the outside of the glove.
THE PRIOR ART
Gloves have been employed as carriers to dispense or administer medicaments
or cosmetic agents to the skin of the wearer. The following U.S. Patents
are typical of such disclosures:
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Schneiderman No. 4,567,065
Buchalter No. 3,896,807
Cozza et al. No. 3,384,083
Migliarese No. 3,347,233
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These disclosures differ in principle from this invention in that it is not
the purpose of the gloves of this invention to serve as a means for
administering a medically active agent to the wearer. Rather, it is the
intent of this invention to provide a means for maintaining, as far as is
practical, the sterility of a surgeon's glove by providing small amounts
of an antimicrobial agent to the hand/glove interface.
DETAILED DESCRIPTION OF THE INVENTION
As used herein, "antimicrobial" refers to a composition having fungicidal,
bactericidal, and/or bacteriostatic properties.
Natural rubber surgical gloves are commonly produced by employing a dip
process. Glazed or bisque porcelain or plastic molds in a configuration
duplicating the human hand are dipped into compounded natural rubber latex
to result in a thin rubber glove. To establish a predictable, reproducible
rubber layer on the molds, a coagulant layer is first dipped onto the
clean molds. These coagulant coated molds are dipped into the latex
compound, which gels into a layer. The rubber gel is leached in water to
extract a large percentage of the soluble components of the compound.
After leaching, the gloves are dried and cured.
The finished rubber gloves would have too much surface tack to allow
removal from the molds without ancillary treatments or additives to the
process. A common approach utilizes inert or nontoxic powders in the
coagulant and in a post-dip applied after the gloves are dried and cured.
A common powder that is suspended in the coagulant is calcium carbonate.
The calcium carbonate isolates the rubber film from the mold, facilitating
removal of the finished gloves. It also becomes a residual antiblocking
agent on the exterior surface of the finished gloves. The powder applied
after the glove is cured is commonly epichlorohydrin cross-linked
cornstarch which becomes an antiblock and donning assist on the inside of
the finished gloves. Both of the aforementioned powders are believed to be
bioabsorbable if left in a wound site.
Some of the antimicrobials employed in the invention have an affinity for
the aforementioned cross-linked cornstarch. Because of this trait,
excellent antimicrobial activity is obtained on the inside of gloves
dipped into a starch slurry containing such antimicrobials, and this
comprises one aspect of the invention, namely, a surgical glove having a
layer of cross-linked starch on the inner surface thereof, wherein the
starch has absorbed thereon an effective amount of an antimicrobial agent.
Salts of chlorhexidine, 1,6-di(4-chlorophenyl diguanido)hexane are
bactericides which exhibit affinity for cross-linked cornstarch. These
salts are adsorbed on the surface of cross-linked cornstarch and will
release slowly therefrom in the presence of moisture such as perspiration.
Typical salts of chlorhexidine are the dihydrochloride, dihydroiodide,
diperchlorate, dinitrate, dinitrite, sulphate, sulphite, thiosulphate,
di-acid phosphate, difluorophosphate, diformate, diacetate, dipropionate,
di-isobutyrate, di-n-valerate, dicaproate, malonate, succinate, malate,
tartrate, dimonoglycolate, monodiglycolate, dilactate,
di-.alpha.-hydroxyisobutyrate, digluconate, diglucoheptonate,
di-isethionate, dibenzoate, dicinnamate, dimandelate, di-isophthalate,
di-2-hydroxynapthoate, and embonate.
Another fmaily of antimicrobials that can be used in the invention are the
biguanides or salts thereof such as polyhexamethylene biguanide
hydrochloride ("PHMB"). PHMB is commercially available as COSMOCIL CQ from
ICI Americas, Inc. The use of PHMB in the adhesive layer of an incise
drape to render the drape antimicrobial is described by Brown in U.S. Pat.
No. 4,643,181.
Chlorinated phenols of the type described in U.s. Pat. Nos. 2,919,200 and
3,308,488 to Dubin et al. and Schoonman, respectively, which are
compounded into synthetic yarns to render the yarns antimicrobial, are
anti-bacterial agents having a decomposition temperature above the curing
temperature of the elastomers that can be used with relative safety in
contact with human skin. Such chlorinated phenols kill disease producing
microorganisms including bacteria and fungi. Specifically, the
antibacterial agents disclosed by Dubin et al., i.e.,
2,2'-thiobis(4,6-dichlorophenol) and
2,2'-methylenebis(3,4,6-trichloro)phenol may be employed. Even more
preferably, because of its overall properties, an antimicrobial agent
which can be utilized to fulfill the purposes of the invention is
2,4,4'-trichloro-2'-hydroxyphenyl ether, which has a USAN nonproprietary
designation of triclosan. This material is marketed under the trade name
"Irgasan DP-300" by the CIBA-GEIGY Corporation. Other antibacterial or
fungicidal agents that are safe for use in contact with the skin may also
be used. Such additional agents include nitrophenyl acetate, phenyl
hydrazine, and polybrominated salicylanilides, such as
5,4'-dibromosalicylanilide and 3,5,4'-tribromosalicylanilide.
Several types of antimicrobials have been disclosed above which can be
employed in the invention. The scope of the invention should not be
limited to the specifically disclosed materials, but also includes their
functional equivalents. Any antimicrobial that has low toxicity and low
sensitization potential at effective use concentrations can be employed in
the invention.
Because it is not the intent of the gloves of this invention to administer
the active ingredient to the wearer of the glove, the inner coating is
free of any additive materials that would tend to deliver the active
ingredient to the wearer. The types of additive materials that are
excluded include vehicles that would cause the active antimicrobial
ingredient to pass through the skin of the wearer such that the active
ingredient would be delivered systemically, and additive materials that
would tend to enhance the adhesion or persistence of the active
antimicrobial ingredient on the skin of the wearer. Preferably, the inner
coating is free of all non-standard materials except for the antimicrobial
agent. (By "non-standard" materials is meant materials that are not
normally present on the inner surface of a medical glove.)
In another aspect of the invention, an antimicrobial may be incorporated in
a surface layer on the gloves that are manufactured with powder-free
processes, as discussed below. Surgical gloves made without powder on the
inner surface must have that surface modified to allow donning. A method
is described in U.S. Pat. Nos. 4,070,713 and 4,143,109. This approach
necessitates the application of a low coefficient of friction ("C.O.F.")
elastomeric coating to the inside of the gloves. These coatings can by any
low C.O.F. plastic or elastomer with adequate adhesion to the natural
rubber substrate and with physical stress/strain properties, i.e.,
tensile, modulus, and elongation compatible with the substrate,
Elastomeric coatings applicable to this approach are carboxylated styrene
butadiene latices, carboxylated butadiene acrylonitrile latices,
sulfo-brominated butyl latices, polyurethane latices, vinyl acrylate
latices, polyurethane solvent solutions, and several block copolymers as
solvent solutions. Block copolymers which can be used include
styrene/butadiene/styrene, styrene/isoprene/styrene and
styrene/butylene/styrene. The examples given are not intended to limit or
to suggest that only these elastomers can be used to fulfill the concept
of this variation.
In the experimental section below, the antimicrobial activity of the
particular variation of antimicrobial gloves was determined in the
following manner. One tenth of a milliliter of each of the test
suspensions of particular bacteria in 0.1 percent peptone growth medium
were applied to the antimicrobial containing side of a two-inch square
piece of the glove which had been placed in a petri dish. The glove had
been presterilized in a sealed package by exposure to gamma radiation. The
petri dish is then placed in a high humidity (95%) incubator at 35.degree.
C. for the particular exposure times. Controls, when used, were identical
to the treated gloves except for the absence of the antimicrobial active
ingredient. At the end of the exposure period, 20 mL of neutralizer
solution was added to each petri dish containing a glove sample (2-inch
square piece). The petri dishes containing the neutralizer were swirled in
order to inactivate the antimicrobial and to remove the viable organisms
from the surfaces of the glove samples. After 10 seconds of swirling,
aliquots of the neutralizer medium were taken for enumeration of the
viable organisms using the standard pour plate technique. (Reference: P.
Gerhardt et al., MANUAL OF METHOD FOR GENERAL BACTERIOLOGY, Chapter 11,
page 185, American Society for Microbiology, Washington, D.C., 1981.) The
colonies were counted to determine the log.sup.10 for surviving bacteria
after each exposure time.
EXAMPLE 1
Natural rubber surgical gloves were manufactured in a conventional manner.
After the drying and curing ovens, the following mixture was dipped or
sprayed on the glove as an aqueous slurry:
1.0 g of 50% active silicone emulsion LE-46HS
2.5 g of 20% chlorhexidine gluconate
8.0 g of a 50% slurry of epichlorohydrin cross-linked cornstarch
The 50% cross-linked starch slurry contained 2.5 g of Gelvatol 20-60
polyvinyl alcohol and a total of 86 g of deionized water. The mixture is
dipped or sprayed onto the warm gloves as they exit the ovens. After the
mixture dries, the gloves are stripped from the forms. The gloves are
reversed during stripping, which places the antimicrobial, starch powder,
and silicone mixture on the inside of the gloves. Results of an evaluation
of the bactericidal activity of the coated side of the glove are shown in
Table I, below.
EXAMPLE 2
Natural rubber surgical gloves were manufactured in a conventional manner.
A post dip of the following mixture was applied after the curing ovens, as
described in Example 1: 1.0 g of 50% active silicone emulsion LE-46HS, 2.5
g of 20% active PHMB, and 8 g of a 50% slurry of cross-linked cornstarch.
The 50% slurry of cross-linked cornstarch contained National 1142:140
cross-linked starch and 2.4 g of Gelvatol 20-60 polyvinyl alcohol in 86 g
of deionized water. The latter was dipped onto the gloves. Results of the
evaluation of the bactericidal properties of the coated glove are shown
below in Table I.
EXAMPLE 3
Using conventional procedures for making surgical gloves, the natural
rubber substrate is formed on the glove mold. After the gelled natural
latex compound has been leached, and prior to drying and curing, the
following solution is dipped over the substrate.
Dissolve 15 g of Estane 5707, polyurethane elastomer, in 20 g of
tetrahydrofuran, 20 g of toluene, 25 g of 1,4-dioxane, and 20 g of
N,N-dimethylformamide (DMF). To the resultant solution, blend in 2.25 g of
aqueous 20% PHMB. Results of the antibacterial testing are displayed in
Table I, below.
EXAMPLE 4
As a control, gloves were prepared as outlined in Example 1, omitting only
the antimicrobial.
EXAMPLE 5
Gloves are dipped as described in Example 3. The following polyurethane
latex compound is overdipped prior to the dry and cure ovens:
To 50 g of 30% cationic urethane latex Neorez XP-7058, add 1.5 g of 30%
cetyl trimethyl ammonium bromide, 0.6 g of 20% chlorhexidine gluconate,
and 2.36 g of cross-linked starch 1142:140. Results of the antibacterial
testing are shown below in Table I.
EXAMPLE 6
Gloves are dipped as described in Example 3. The following hypalon latex
compound is overdipped prior to the dry and cure ovens:
To 200 g of 50% HYP-605 latex (chlorosulfonated polyethylene), add 5 g of
40% amphoterge SB (an amphoteric surfactant), 6 g of 50% pentaerythritol
solvent, 4.33 g of 60% zinc oxide, 3.63 g of 55% dipentamethylene thiuram
hexasulfide, 30 g of 50% Vedoc VP-180 urethane powder (used as an
encapsulated low C.O.F. donning powder), 20 g of 50% Witcobond XW modified
epoxy resin film forming polymer, 3 g of
2,4,4'-trichloro-2'-hydroxydiphenyl ether (triclosan), 1.33 g of 38% EDTA,
and 3.00 g of diethylene glycol solvent. Results of the antibacterial
testing are shown below in Table I.
EXAMPLE 7
As a control for one of the powder-free concepts, gloves were dipped as
described in Example 6, omitting only the antimicrobial. Results of the
antibacterial testing are shown below in Table I.
TABLE I
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BACTERIAL % KILL
Count/% Kill
Example Initial Count
10 Min. 30 Min.
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Example 1
160,000 0/100% 0/100%
Example 2
140,000 0/100% 0/100%
Example 3
130,000 15/99.988% 0/100%
Example 4
180,000 120,000/33.3%
130,000/27.8%
Control
Example 5
140,000 85,000/39.3%
36,000/74.3%
Example 6
200,000 61,000/61.88%
5,100/96.81%
Example 7
160,000 120,000/25.0%
16,000/90%
Control
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The Example 7 control is most properly compared only with Example 6 (which
used the same latex coating on the inner surface of the glove).
Apparently, this latex coating itself has mild antimicrobial activity.
In order to determine the order of magnitude of the rate of release of the
antimicrobial agent from the coating in the medical glove, the following
experiments were performed:
By procedures analogous to those described above in Examples 3-7, surgical
gloves having low C.O.F. coatings containing antimicrobial agents were
coated with the following aqueous mixtures:
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Example 8
Parts, by Parts, by
Material weight, dry
% Solids weight, wet
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Deionized water
-- -- 206.535
Witcobond W-212.sup.(1)
100 29.6 337.84
Chlorhexidine gluconate
3 20.0 15.0
Geon 213.sup.(2)
15 50.0 30.0
Amphoterge SB.sup.(3)
0.125 10.0 1.25
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Example 9
Parts, by Parts, by
Material weight, dry
% Solids weight, wet
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Deionized water
-- -- 297.25
Neorez R-967.sup.(4)
30.0 40.0 75.0
Neorez R-962.sup.(5)
70.0 34.0 205.88
Vedoc VP-180.sup.(6)
17.65 50.0 35.3
Triclosan 6.0 100.0 6.0
Propylene glycol
6.0 100.0 6.0
Versene 100.sup.(7)
1.0 38.0 2.64
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.sup.(1) An aqueous dispersion of fully reacted urethane polymer.
.sup.(2) A calender grade polyvinyl chloride resin
.sup.(3) A sulfonated amphoteric surfactant. CFTA adopted name is
"Amphoteric 13". The Geon 213 and Amphoterge SB were premixed prior to
addition to the aqueous mixture.
.sup.(4) and .sup.(5) Colloidal dispersions of high molecular weight
aliphatic urethane polymers
.sup.(6) An aqueous polyester urethane polymer powder mixture
.sup.(7) Na salt of EDTA
The gloves prepared as described above in Examples 8 and 9 were tested for
extraction of the antimicrobial agents in the following manner:
Fifty ml of physiological saline was placed in each sample glove. The
gloves were hung in a 100.degree. F. oven to simulate body temperature,
and aliquots of saline were removed from each glove after 30 minutes and
after 1, 2, and 4 hours. The removed samples were analyzed by a
spectrophotometer for extracted antimicrobial agent. The results are
reported below as ppm of extracted antimicrobial agent in the saline:
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Example 8 Example 9
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30 min. 3.0 <0.5
1 hr. 3.1 <0.5
2 hrs. 4.6 .about.0.8-1.0
4 hrs. 6.9 .about.0.8-1.0
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