WO1997017849A1

WO1997017849A1 - Triple antimicrobial composition

Info

Publication number: WO1997017849A1
Application number: PCT/US1996/018104
Authority: WO
Inventors: Shanta Modak; Lester Sampath
Original assignee: The Trustees Of Columbia University Of The City Of New York
Priority date: 1995-11-13
Filing date: 1996-11-12
Publication date: 1997-05-22
Also published as: AU7677996A; US5985931A; US5705532A

Abstract

The present invention relates to antimicrobial compositions comprising (i) less than or equal to two percent by weight chlorhexidine or chlorhexidine salt; (ii) less than or equal to .1 percent by weight of a quaternary ammonium compound, such as benzalkonium chloride; and (iii) less than or equal to two percent by weight of parachlorometaxylenol. The antimicrobial compositions of the invention may be utilized in antimicrobial detergents, soaps, creams, rinses, and emulsions for use in the medical community as well as general public use.

Description

TRIPLE ANTIMICROBIAL COMPOSITION

1. INTRODUCTION

The present invention relates to antimicrobial compositions comprising chlorhexidine, a quaternary ammonium compound and parachlorometaxylenol. It is based, at least in part, on the discovery that chlor¬ hexidine, benzalkonium chloride, and parachloro¬ metaxylenol exhibit synergistic antimicrobial activity.

2. BACKGROUND OF THE INVENTION The antimicrobial agents chlorhexidine ("CHX"; 1,6 bis(N⁵ -p-chlorophenyl-N¹ -biguanido)hexane) , benzal¬ konium chloride ("BZK") and parachlorometaxylenol ("PCMX") have been used, individually, in antimicrobial compositions. For example, the well-known antiseptic scrubs Hibiclens®, Ultradex® and Techni-care® contain 4% CHX (Hibiclens®) and 3% PCMX (Ultradex® and Technicare®) . The use of these scrubs, however, pro¬ vides less than optimal antimicrobial protection, in that neither scrub is believed to be fully effective in rapidly inactivating pathogens or in reducing skin flora for an extended period of time. Furthermore, the relatively high levels of antimicrobial agents in these preparations are frequently associated with skin irritation. Compositions which combine one or more of the foregoing antimicrobial agents with additional com¬ pounds are also known, as illustrated by the following references.

United States Patent No. 5,244,666 by Murley, issued September 14, 1993 ("the '666 patent") relates to an antiseptic scrub and wound disinfectant wherein a quaternary ammonium compound and a substituted phenolic compound are combined to produce enhanced antimicrobial activity at lower concentrations. The '666 patent states that the use of such combinations, together with degreasing emulsifiers, detergents, skin softeners and soothing agents is new. The compositions comprise about 3% (wt/wt) of a quaternary ammonium compound and about 3% of a substituted phenolic compound.

United States Patent No. 5,030,659 by Bansemir et al., issued July 9, 1991 ("the '659 patent") relates to disinfectant compositions comprising a quaternary ammonium compound, a biguanide, and a phenolic com¬ pound. The antimicrobial agent present in greatest concentration is the quaternary ammonium compound; the working examples of the '659 patent include composi¬ tions comprising 15-20% of the quaternary ammonium compound BZK.

United States Patent No. 4,900,721 by Bansemir et al., issued February 13, 1990, relates to liquid, aqueous disinfectants based on alcohol and hydrogen peroxide which comprise one or more C₂ - C₈ alcohols, hydrogen peroxide (or a compound which produces hydro¬ gen peroxide) , one or more carboxylic acids, one or more microbicidally active nitrogen-containing organic compounds (e.g.. CHX or BZK) , and one or more micro¬ bicidally active phenolic compounds (including poly- chlorinated xylenes) .

United States Patent No. 4,420,484 by Gorman et al., issued December 13, 1983, relates to combinations of antimicrobial agents (such as CHX or BZK) with poly¬ ethylene glycol surfactant and betaine or amine oxide surfactant.

United States Patents Nos. 4,125,628 and 4,022,911, by Goldhaft et al., issued November 14, 1978 and May 10, 1977, respectively, relate to combinations of a quaternary ammonium compound, a phenol or deriva¬ tive thereof, and formaldehyde.

United States Patent No. 3,639,632 by McNamara et al., issued February 1, 1972, relates to a synergistic antimicrobial composition containing 1,1'-hexamethyl- enebis [5 ~(2-ethylhexyl)biguanide] dihydrochloride and 4-chloro-2-hydroxyphenyl, 2,4-dichlorophenyl ether.

Larson et al., 1992, J. Emergency Med. iχ>: 7-11 discloses that in the presence of blood, topical anti- microbial products containing alcohol were associated with greater initial reductions in colonizing flora.

The number of antimicrobial preparations which have been developed illustrates the continuing search for a composition that rapidly and effectively provides antimicrobial activity without substantial adverse effects, such as skin irritation.

3. SUMMARY OF THE INVENTION

The present invention relates to antimicrobial compositions comprising (i) less than or equal to two percent by weight chlorhexidine or chlorhexidine salt; (ii) less than or equal to .1 percent by weight of a quaternary ammonium compound, such as benzalkonium chloride; and (iii) less than or equal to two percent by weight of parachlorometaxylenol. The antimicrobial compositions of the invention may be utilized in anti¬ microbial detergents, soaps, creams, rinses, and emulsions for use in the medical community as well as general public use; they offer the advantages of effective antimicrobial activity at low concentrations of each of the active ingredients.

4. DETAILED DESCRIPTION OF THE INVENTION

The present invention relates to antimi- crobial compositions comprising (i) less than or equal to two percent by weight chlorhexidine or chlorhexidine salt; (ii) less than or equal to .1 percent by weight of a quaternary ammonium compound, such as benzalkonium chloride; and (iii) less than or equal to two percent by weight of parachlorometaxylenol. In a preferred, nonlimiting embodiment of the invention, where the composition is to be used as an antimicrobial scrub, the concentration of chlorhexidine or chlorhexidine salt is between one and two percent (inclusive) . In alternate nonlimiting embodiments of the invention, the concentrations of chlorhexidine or chlorhexidine salt in the compositions are between .05 and .1 percent by weight (inclusive), and, in specific embodiments, equal to 0.05 percent or 0.1 percent by weight. The term "chlorhexidine" refers to non-salt compositions of chlorhexidine, including chlorhexidine free base. Chlorhexidine salts that may be used according to the invention include but are not limited to the following: chlorhexidine diphosphanilate, chlor¬ hexidine digluconate, chlorhexidine diacetate, chlor- hexidine dihydrochloride, chlorhexidine dichloride, chlorhexidine dihydroiodide, chlorhexidine diper- chlorate, chlorhexidine dinitrate, chlorhexidine sul¬ fate, chlorhexidine sulfite, chlorhexidine thiosulfate, chlorhexidine di-acid phosphate, chlorhexidine difluoro- phosphate, chlorhexidine diformate, chlorhexidine dipropionate, chlorhexidine di-iodobutyrate, chlorhexidine di-n-valerate, chlorhexidine dicaproate, chlorhexidine malonate, chlorhexidine succinate, chlorhexidine malate, chlorhexidine tartrate, chlorhexidine dimonoglycolate, chlorhexidine ono- diglycolate, chlorhexidine dilactate, chlorhexidine di- α-hydroxyisobutyrate, chlorhexidine diglucoheptonate, chlorhexidine di-isothionate, chlorhexidine dibenzoate, chlorhexidine dicinnamate, chlorhexidine dimandelate, chlorhexidine di-isophthalate, chlorhexidine di-2- hydroxynapthoate, and chlorhexidine embonate. Compositions may alternatively comprise less than 2 percent (preferably .025-.l%) polyhexamethylene biguanide ("PHMB") . Quaternary ammonium compounds that may be used according to the invention include, but are not limited to, benzalkonium chloride (BZK) , benzethoniu chloride, other benzalkonium or benzethonium halides, cetyl- pyridinium chloride, dequalinium chloride, N-myristyl- N-methylmorpholinium methyl sulfate, poly[N-[3-

(dimethylammonio)propyl]-N'-[3-(ethyleneoxyethelene dimethylammonio)propyl]urea dichloride], alpha-4-[l- tris(2-hydroxyethyl)ammonium chloride-2-butenylJ-omega- tris(2-hydroxyethyl)ammonium chloride, alpha-4-[l- tris(2-hydroxyethyl)ammonium chloride-2-butenyl]poly[l- dimethyl ammonium chloride-2-butenyl]-omega-tris(2- hydroxyethyl)ammonium chloride, poly[oxy¬ ethylene(dimethyliminio)ethylene(dimethyliminio)- ethylene dichloride], ethyl hexadecyl dimethyl ammonium ethyl sulfate, dimethyl ammonium ethyl sulfate, dimethylethylbenzyl ammonium chloride, dimethylbenzyl ammonium chloride, and cetyldimethylethyl ammonium bromide. In preferred nonlimiting embodiments, the quaternary ammonium compound is benzalkonium chloride. In particularly preferred nonlimiting embodiments of the invention, where the composition is to be used as an antimicrobial scrub, the concentration of benzal¬ konium chloride is less than or equal to .1 percent. In alternate embodiments, the concentration of benzal- konium chloride is between 0.005 and 0.01 percent by weight (inclusive) .

The compositions of the invention may further comprise an organic solvent that aids in the dissolu¬ tion of the antimicrobial agents, for example, isopro- panol or propylene glycol. The amount of isopropanol in the compositions of the invention is preferably between -6-

2.5 and 5 percent by weight (inclusive). In specific preferred embodiments, the amount of isopropanol is 5 percent by weight.

In preferred embodiments of the invention, where the composition is to be used as an antimicrobial scrub, the amount of parachlorometaxylenol is less than or equal to 2 percent. In alternate embodiments, the amount of parachlorometaxylenol is between .05 and .25 percent by weight, inclusive. In yet another embodiment, the present invention provides for a scrub base that is believed to enhance the effectiveness of antimicrobial agents. This base comprises 10-15 percent of a pluronic copolymer sur¬ factant, including but not limited to pluronic F87; 1-5 percent of an amine oxide foaming agent, including but not limited to lauryl dimethylamine oxide; 0.2-0.25 percent of a foam enhancer such as, but not limited to, glucamate DOE 120; one or more antimicrobial agent; and water, wherein the pH has been adjusted to 5.5-6.0 with a mild acid such as, but not limited to, gluco- nolactone, lactic acid, salicylic acid, citric acid or gluconic acid. Suitable antimicrobial agents include, but are not limited to, parachlorometaxylenol, phenoxy- ethanol, povidone iodine, chlorhexidine or a chlor- hexidine salt, benzalkonium chloride, and combinations thereof. Compounds such as isopropanol or propylene glycol may also be used to improve the solubility of antimicrobial agent.

It has surprisingly been found that, contrary to the teachings of the prior art, a non-ionic surfactant such as Pluronic F87 is compatible with parachloro¬ metaxylenol. The prior art generally teaches the use of amphoteric or anionic surfactants in parachloro¬ metaxylenol formulations. The compositions of the invention may be incorporated into a variety of products, including, but not limited to hand disinfectants, hand soaps, topical creams, antiseptic rinses or soaks, and antiseptic towlettes. Likewise, they may be incorporated as preservatives, for example, in cosmetics. Such products may be prepared according to methods known in the art. The present invention provides for the following specific, preferred, nonlimiting embodiments:

The present invention provides for an antimi- crobial scrub having the following composition: 2 grams parachlorometaxylenol; 2 grams chlorhexidine diglu- conate; 0.1 gram benzalkonium chloride; 5.0 ml isopro¬ panol; 12.5 grams pluronic F87; 1.8 grams lauryl dimethylamine oxide; 0.25 grams glucamate DOE; 1 gram D-glucanolactone; and 75.35 grams deionized water; wherein the pH is adjusted to between 5.5-6.0 with D- glucanolactone. In related embodiments, 2-10 percent cocamidopropyl betaine may be added to the above- identified composition. In another related embodiment, the present invention provides for an antimicrobial scrub having the following composition: 2 grams parachloro¬ metaxylenol; 2 grams chlorhexidine digluconate; 0.1 gram benzalkonium chloride; 10 grams propylene glycol; 12.5 grams pluronic F87; 1.8 grams lauryl dimethylamine oxide; 0.25 grams glucamate DOE; 1 gram D-glucano¬ lactone; and 75.35 grams deionized water; wherein the pH is adjusted to between 5.5-6.0 with D-glucano¬ lactone. In related embodiments, 2-10 percent cocami- dopropyl betaine may be added to the above-identified composition.

In another specific embodiment, the present invention provides for an antimicrobial scrub having the following composition: 3 percent parachloro- metaxylenol; 1 percent phenoxyethanol; 10 percent propylene glycol; 10 percent pluronic F87; 1.8 percent lauryl dimethylamine oxide; 0.25 percent glucamate DOE 120; 1 percent D-gluconolactone; and 73 percent deionized water. In a related embodiment, this scrub may further comprise 0.1 percent benzalkonium chloride. In still further related embodiments, such a scrub, with or without benzalkonium chloride, may further comprise 2-10 percent coca idopropyl betaine.

In another specific embodiment, the present invention provides for an antimicrobial scrub having the following composition: 5 percent povidone iodine; 10 percent propylene glycol; 1 percent phenoxyethanol; 10 percent pluronic F87; 1.8 percent lauryl dimethamine oxide; 0.25 percent glucamate DOE 120; 1 percent D- gluconolactone; and 71 percent deionized water. In yet another specific embodiment, the present invention provides for an antimicrobial scrub having the following composition: 5 percent povidone iodine; 10 percent propylene glycol; 10 percent Pluronic F87; 1.8 percent lauryl dimethylamine oxide; 0.25 percent glucamate DOE; 1 percent D-gluconolactone; and 72 percent deionized water.

In another specific embodiment, the present invention provides for an antimicrobial scrub having the following composition: 3 percent parachloro- metaxylenol; 10 percent propylene glycol; 1 percent phenoxyethanol; 10 percent pluronic F87; 1.8 percent lauryl dimethamine oxide; 0.25 percent glucamate DOE 120; 1 percent D-gluconolactone; and 71 percent deionized water. In yet another specific embodiment, the present invention provides for an antimicrobial scrub having the following composition: 3 percent parachloro¬ metaxylenol; 10 percent propylene glycol; 10 percent Pluronic F87; 1.8 percent lauryl dimethylamine oxide; 0.25 percent glucamate DOE; 1 percent D-gluconolactone; and 72 percent deionized water. The compositions of the invention may further comprise quaternaries such as isostearyl ethylimidonium ethosulfate ("ISIES") , polyoxyethylene dihydroxypropyl linoleaminium chloride ("SL-5") . and bishydroxyethyl dihydroxypropyl stearaminium chloride ("TG") , and phospholipids such as cocamidopropyl phosphatidyl PG- dimonium chloride ("PTC") , linoleamidopropyl phospha¬ tidyl PG-dimonium chloride ("EFA") , and stearami- dopropyl phosphatidyl PG-dimonium chloride and cetyl alcohol ("SV") , obtainable from Mona Industries, Paterson, New Jersey.

The usefulness of the present invention is demon¬ strated by the following examples, set forth as exam¬ ples only, and not by way of limitation. It should be noted that the concentrations of active agents are lower than those used in currently available products, thereby diminishing the risk of skin irritation, but providing effective antimicrobial protection.

5. EXAMPLES: SYNERGISM OF PCMX. CHX AND BZK

Table 1 shows the results when various concentra¬ tions of PCMX in 2.5% isopropanol ("ISOPR") were exposed to Staphylococcus aureus bacteria. To produce each sample, 0.1 ml of a ten-fold concentrated anti- microbial solution was added to 0.9 ml of TSB broth containing 20% serum and IO⁷ colony forming units (CFU) of Staphylococcus aureus . After one minute, a 50 microliter aliquot from each sample was diluted to a volume of 10 ml with LTSB drug inactivating medium (5% Tween 80, 2% lecithin, 0.6% sodium oleate, 0.5% sodium thiosulfate, 0.1% protease peptone and 0.1% tryptone), and then 0.5 ml of the diluted culture was plated on trypticase soy agar plates. The plates were incubated at 37°C for 24 hours, and then colony counts per mil- liliter of the original 1 ml antimicrobial containing culture were determined. Table 1

Sample Al Bl Cl Dl El Fl

%PCMX 0 .01 .02 .03 .04 .05

%ISOPR 2.5 2.5 2.5 2.5 2.5 2.5

CFU/ml lxlO⁷ 8xl0⁶ 4X10⁶ 3.5X10⁶ 1.8X10⁵ lxlO⁶

Table 1 demonstrates that as the concentration of PCMX was increased from 0 to .05%, a reduction of CFU by approximately a factor of ten was observed.

Table 2 shows the results of experiments in which .05% chlorhexidine was added to the compositions tested in Samples Al - Fl, as described in Table 1. The cor¬ responding samples, containing .05% chlorhexidine, are designated A2 - F2.

Table 2

Sample A2 B2 C2 D2 E2 F2

%PCMX 0 .01 .02 .03 .04 .05

%CHX .05 .05 .05 .05 .05 .05

%ISOPR 2.5 2.5 2.5 2.5 2.5 2.5

CFU/ml 8X10⁶ 2X10⁵ 7xl0⁴ 7xl0³ 0 0

Table 2 demonstrates that .05% CHX, used alone, had very little effect on the number of CFU present in control sample Al (lxlO⁷ CFU) , in that control sample A2 exhibited 8xl0⁶ CFU. Similarly, sample Bl, which contained .01% PCMX, exhibited 8xl0⁶ CFU. However, the combination of .01% PCMX and .05% CHX in sample B2 resulted in an approximately 40- fold drop in the number of CFU relative to control A2 (to 2xl0⁵ CFU) . Moreover, although .03% PCMX reduced the number of CFU by a factor of 3 relative to control Al to 3.5xl0⁶ (sample Dl) , the combination of .03% PCMX and .05% CHX decreased the number of CFU by approximately a factor of 1000 relative to control A2 (to 7xl0³ CFU, sample D2) . The combination of .04% PCMX and .05% CHX eliminated all CFU (sample E2) . This data demonstrates the synergistic antimicrobial activity of PCMX and CHX, and is corroborated by data presented in Table 3, which combines the amount of PCMX contained in samples Al-Fl with .1% CHX, in corresponding samples A3 - F3.

Table 3

Sample A3 B3 C3 D3 E3 F3

%PCMX 0 .01 .02 .03 .04 .05

%CHX .1 .1 .1 .1 .1 .1

%ISOPR 2.5 2.5 2.5 2.5 2.5 2.5

CFU/ml 9X10⁵ 7X10⁴ 4xl0⁴ 1.2X10³ 0 0

Experiments have also demonstrated the synergistic activity of BZK with PCMX and CHX. Table 4 shows the results of experiments in which .01% BZK was added to the compositions of samples Al and B2 - F2, thereby testing .01% BZK used alone or in combination with .05% CHX and .01 - .05% PCMX in samples A4 - F4. Of note, a control sample for the samples set forth in Table 4, which contained 2.5% ISOPR and no antimicrobial, exhibited 1.2xl0⁷ CFU (not set forth in Table 4). Table 4

Sample A4 B4 C4 D4 E4 F4

%PCMX 0 .01 .02 .03 .04 .05

%CHX 0 .05 .05 .05 .05 .05

%BZK .01 .01 .01 .01 .01 .01

%ISOPR 2.5 2.5 2.5 2.5 2.5 2.5

CFU/ml 4xl0⁶ 8xl0² 0 0 0 0

Table 4 shows that despite the fact that .01% BZK alone (sample A4; 4xl0⁶ CFU) decreased the number of CFU by a factor of only 3 relative to the control sample (1.2X10⁷ CFU), and sample B2 (.01% PCMX + .05% CHX) decreased the number of CFU by a factor of approximately 40 relative to control A2, sample B4 (.01% PCMX + .05% CHX + .01% BZK) exhibited an approximately 10,000- fold decrease in the number of CFU relative to control A4. This data demonstrates the synergistic antimicrobial activity of low concentra¬ tions of PCMX, CHX, and BZK, and is corroborated by the data presented in Table 5, which combines the same amounts of PCMX and CHX with .005% BZK in samples A5 - F5.

Table 5

Sample A5 B5 C5 D5 E5 F5

%PCMX 0 .01 .02 .03 .04 .05

%CHX 0 .05 .05 .05 .05 .05

%BZK .005 .005 .005 .005 .005 .005

%ISOPR 2.5 2.5 2.5 2.5 2.5 2.5

CFU/ml 5X10⁶ 1.2X10³ 0 0 0 0

The experiments described in Tables 1 - 5 were then repeated, except that the amount of isopropanol was increased to 5%

Table 6 depicts the results of experiments in which the amount of isopropanol in samples Al - Fl (Table 1) were increased to 5%.

Table 6

Sample A6 B6 C6 D6 E6 F6

%PCMX 0 .01 .02 .03 .04 .05

%IS0PR 5 5 5 5 5 5

CFU/ml lxlO⁷ 4X10⁶ 2X10⁶ 1.5X10⁵ 9X10⁵ 8X10⁵

The number of CFU in samples A6 - F6 were sub¬ stantially the same (perhaps slightly less) than those exhibited by samples Al - Fl.

Table 7 depicts the results of experiments in which the amount of isopropanol in samples, which otherwise correspond to samples A2 - F2 (Table 2) , was increased to 5%. Table 7

Sample A7 B7 C7 D7 E7 F7

%PCMX 0 .01 .02 .03 .04 .05

%CHX .05 .05 .05 .05 .05 .05

%ISOPR 5 5 5 5 5 5

CFU/ml lxlO⁶ 1.5x10^s 3.5X10⁴ 1.6xl0³ 0 0

The data presented in Table 7 again demon¬ strates the synergistic relationship between CHX and PCMX. Further, the increase in the concentration of ISOPR from 2.5 to 5% seems to have slightly decreased the number of CFU. These results are further corro¬ borated by data presented in Table 8, which relates to samples essentially the same as samples A3 - F3 (Table 3) , except that the amount of isopropanol was increased from 2.5 to 5%.

Table 8

Sample A8 B8 C8 D8 E8 F8

%PCMX 0 .01 .02 .03 .04 .05

%CHX .1 .1 .1 .1 .1 .1

%ISOPR 5 5 5 5 5 5

CFU/ml 9xl0⁵ 4.5X10⁴ 1.5X10³ 0 0 0

Table 9 presents the results of experiments in which the amount of isopropanol, in samples corres¬ ponding to samples A4 - F4 (Table 4) , was increased from 2.5% to 5%. A control sample for the samples set forth in Table 9, containing 5% ISOPR and no anti- microbial exhibited 1.2xl0⁷ CFU (not shown in Table 9). Table 9

Sample A9 B9 C9 D9 E9 F9

%PCMX 0 .01 .02 .03 .04 .05

%CHX 0 .05 .05 .05 .05 .05

%BZK .01 .01 .01 .01 .01 .01

%ISOPR 5 5 5 5 5 5

CFU/ml 1.5X10⁶ 2.6X10² 0 0 0 0

This data corroborates the synergistic relationship between CHX, PCMX, and BZK and further shows that an increase in the amount of isopropanol to 5% decreased CFU slightly. This conclusion is further supported by the results depicted in Table 10, where samples otherwise corresponding to samples A5 - F5 (Table 5) contained 5%, rather than 2.5%, isopropanol.

Table 10

Sample A10 B10 CIO D10 E10 F10

%PCMX 0 .01 .02 .03 .04 .05

%CHX 0 .05 .05 .05 .05 .05

%BZK .005 .005 .005 .005 .005 .005

%ISOPR 5 5 5 5 5 5

CFU/ml 1.5X10⁶ 1.2X10³ 0 0 0 0

The synergistic effectiveness of low concen- trations of CHX and PCMX (in 5% isopropanol) in the presence of blood was also demonstrated, as shown in Table 11. Table 11

Antimicrobial CFU/ml

None (control) 3xl0⁶

.5% CHX lxlO⁵

1% CHX 1X10⁴

.125% PCMX lxlO⁶

.25% PCMX 1.4X10⁴

.5% PCMX 0

.5% CHX + .25% PCMX 0

1% CHX + .125% PCMX 0

6. EXAMPLE: COMPARISON OF SCRUBS PREPARED ACCORDING TO THE INVENTION

The following antimicrobial scrubs were tested for antimicrobial effectiveness.

Scrub A. 3% PCMX

1% phenoxyethanol

10% propylene glycol

10% pluronic F87 1.8% lauryl dimethylamine oxide

0.25% glucamate DOE 120

1% D-gluconolactone

73% deionized water

Scrub B. Scrub A + 0.1% BZK

Scrub C. 3% PCMX

5% isopropanol 12.5% pluronic F87 1.8% lauryl dimethylamine oxide

0.25% glucamate DOE 120 1.0% D-glucanolactone 76.45% deionized water To assess antimicrobial effectiveness, 0.1 ml of each scrub was mixed with 0.9 ml of a culture of

Staphylococcus aureus in TSB containing 10% serum, at 10⁶ CFU per ml. After 15 seconds, a 50 microliter aliquot was removed and diluted to 10 ml using drug inactivating medium (LTSB, see above), and 0.5 ml of the diluted culture was plated onto trypticase soy agar. After incubation at 37° C for 24 hours, colony counts were determined, and the results are shown in Table 12.

Table 12

Scrub CFU/ml

A 0

B 0

C 6 X 10³

Hibiclens 3 x 10⁴

Technicare 6 X 10⁵

Ultradex 1 X 10^s

Control 3 X IO⁶

7. EXAMPLE: ENHANCED ACTIVITY IN NEW SCRUB BASE Various antimicrobial agents and compositions were combined in the following base (made to a volume of 100 ml with deionized water) :

5% isopropanol 12.5% pluronic F87 1.8% lauryl dimethylamine oxide

0.25% glucamate DOE 120 1.0% D-glucanolactone These compositions were tested for antimicrobial effectiveness using the same method set forth in Section 6, above. The results are shown in Table 13.

The scrub base appeared to enhance the effectiveness of PCMX in particular. Table 13

Scrub Base + antimicrobial CFU/ml

2% chlorhexidine digluconate

+ 2% PCMX + 0.1% BZK 0

2% PCMX 1.2 X IO⁴

3% PCMX 6.0 x 10³

2% chlorhexidine digluconate 7.0 x IO⁴

4% chlorhexidine digluconate 1.0 x io⁴ 0.1% BZK 1.5 x IO⁶

3% PCMX + 0.1% BZK 5.0 X IO²

Hibiclens 3.0 x IO⁴

Technicare 6.0 x IO⁵

Ultradex 1 x IO⁵ Control 7.0 x IO⁶

8. EXAMPLE: NEW SCRUB BASE WITH PROPYLENE GLYCOL

Using the same methodology for antimicrobial testing set forth above, the effectiveness of the following scrub was tested, and compared to a com¬ mercially available scrub containing povidone iodine (Betadine®, which contains 10 percent povidone iodine) Scrub D:

5% povidone iodine 10% propylene glycol

1% phenoxyethanol 10% Pluronic F87 1.8% lauryl dimethylamine oxide 0.25% glucamate DOE 120 1% D-gluconolactone

71% deionized water Table 14 Scrub CFU/ml

Scrub D 0

Betadine 3.0 x IO² Control 1.7 x 10⁶

9. EXAMPLE: SCRUB COMPRISING POLYHEXAMETHYLENE BIGUANIDE

Using the same methods set forth in example section 5, above, the rate of kill of compositions comprising PHMB, PCMX, BZK and PXE were tested. As demonstrated by Table 15, synergy was observed between BZK, PHMB, and PCMX at respective concentrations of 0.01%, 0.05%, and 0.05%. Synergy was also observed among 0.1% PXE + 0.05% PHMB + 0.05% PCMX.

Table 15 Rate of Kill of Polvhexamethylene (PHMB) . Parachloro- metaxylenol (PCMX. , Benzalkonium Chloride (BZK.. and

Phenoxyethano1 (PXE. Sinσly and in Combination vs

Staphvclococcus aureus.

ANTIMICROBIALS CONCENTRATION % CFU/mL

PHMB 0.1 4.0 X IO⁶

PHMB 0.05 2.0 X IO⁶

PHMB 0.025 5.0 X IO⁶

PCMX 0.1 1.6 X IO³

PCMX 0.05 5.0 X IO⁶

PXE 0.1 2.0 X IO⁷

BZK 0.02 2.0 X IO⁷

PHMB + PCMX 0.05 + 0.05 2.6 X IO⁴

PHMB + PCMX 0.025 + 0.025 6.0 X IO⁵

PHMB + PCMX 0.05 + 0.05 2.2 X IO³

+ BZK + 0.1

PHMB + PCMX 0.05 + 0.05 1.9 X IO³

+ PXE + 0.1

PHMB + PCMX 0.025 + 0.025 1.1 X IO⁵

+ PXE + 0.1

Control none 2.0 X 10'

Various publications are cited herein, the disclosures of which are hereby incorporated by reference in their entireties.

Claims

Claims 1. An antimicrobial composition comprising (i) less than or equal to two percent of an antimicrobial agent selected from the group consisting of chlorhexidine and a chlorhexidine salt; (ii) less than or equal to .1 percent of a quaternary ammonium compound; and (iii) less than or equal to 2 percent parachlorometaxylenol.

2. The composition of claim 1, wherein the quaternary ammonium compound is benzalkonium chloride.

3. The composition of claim 1, which comprises chlorhexidine.

4. The composition of claim 3, wherein the concentration of chlorhexidine is 2 percent by weight and the concentration of parachlorometaxylenol is 2 percent by weight.

5. A composition comprising: (a) an antimicrobial agent: (b) 10-15 percent of a pluronic copolymer surfactant; (c) 1-5 percent of an amine oxide foaming agent; and (d) 0.2-0.25 percent of a foam enhancer.

6. The composition of claim 5, wherein the pluronic copolymer is pluronic F87.

7. The composition of claim 5, wherein the amine oxide foaming agent is lauryl dimethylamine oxide.

8. The composition of claim 6, wherein the amine oxide foaming agent is lauryl dimethylamine oxide.

9. The composition of claim 5, wherein the foam enhancer is glucamate DOE 120.

10. The composition of claim 6, wherein the foam enhancer is glucamate DOE 120.

11. The composition of claim 7, wherein the foam enhancer is glucamate DOE 120.

12. The composition of claim 8, wherein the foam enhancer is glucamate DOE 120.

13. The composition of claim 5, wherein the antimicrobial agent is a mixture of (i) 2 percent of an antimicrobial selected from the group of chlorhexidine and a chlorhexidine salt; and (ii) 2 percent parachlorometaxylenol.

14. The composition of claim 6, wherein the antimicrobial agent is a mixture of (i) 2 percent of an antimicrobial selected from the group of chlorhexidine and a chlorhexidine salt; and (ii) 2 percent parachlorometaxylenol.

15. The composition of claim 7, wherein the antimicrobial agent is a mixture of (i) 2 percent of an antimicrobial selected from the group of chlorhexidine and a chlorhexidine salt; and (ii) 2 percent parachlorometaxylenol.

16. The composition of claim 8, wherein the antimicrobial agent is a mixture of (i) 2 percent of an antimicrobial selected from the group of chlorhexidine and a chlorhexidine salt; and (ii) 2 percent parachlorometaxylenol. -23 -

17. The composition of claim 9, wherein the antimicrobial agent is a mixture of (i) 2 percent of an antimicrobial selected from the group of chlorhexidine and a chlorhexidine salt; and (ii) 2 percent parachlorometaxylenol.

18. The composition of claim 10, wherein the antimicrobial agent is a mixture of (i) 2 percent of an antimicrobial selected from the group of chlorhexidine and a chlorhexidine salt; and (ii) 2 percent parachlorometaxylenol.

19. The composition of claim 11, wherein the antimicrobial agent is a mixture of (i) 2 percent of an antimicrobial selected from the group of chlorhexidine and a chlorhexidine salt; and (ii) 2 percent parachlorometaxylenol.

20. The composition of claim 12, wherein the antimicrobial agent is a mixture of (i) 2 percent of an antimicrobial selected from the group of chlorhexidine and a chlorhexidine salt; and (ii) 2 percent parachlorometaxylenol.

21. A composition comprising: (a) parachlorometaxylenol: (b) 10-15 percent of a non-ionic pluronic copolymer surfactant; (c) 1-5 percent of an amine oxide foaming agent; and (d) 0.2-0.25 percent of a foam enhancer.

22. A composition comprising: (a) povidone iodine: (b) 10-15 percent of a non-ionic pluronic copolymer surfactant; (c) 1-5 percent of an amine oxide foaming agent; and (d) 0.2-0.25 percent of a foam enhancer.

23. An antimicrobial composition comprising (i) less than or equal to two percent of polyhexamethylene biguanide; (ii) less than or equal to .1 percent of a quaternary ammonium compound; and (ϋi) less than or equal to 2 percent parachlorometaxylenol.

24. The composition of claim 23 wherein the amount of polyhexamethylene biguanide is about .025-.1 percent.