Synergistic Mixtures Of Diphenylbismuth Acetate And The Zinc Salt Of 1-hydroxy-2-pyridine Thione Effect As Antibacterial And Antifungal Agents

Abstract

Mixtures of the heavy metal salts of 1-hydroxy-2-pyridinethione and either diphenylbismuth acetate, bismuth trichloride, bismuth formic iodide, or bismuth subgallate, provide synergistic antibacterial and antifungal activity, especially against Pseudomonas aeruginosa; compositions containing said mixture exhibit this same antibacterial and antifungal effectiveness.

Parent Case Text

REFERENCE TO RELATED APPLICATION

This application is a continuation of my copending application Ser. No. 98,085, filed Dec. 14, 1970, for "SYNERGISTIC MIXTURES OF DIPHENYLBISMUTH ACETATE AND THE ZINC SALT OF 1-HYDROXY-2-PYRIDINETHIONE AND COMPOSITIONS CONTAINING SAME", now abandoned.

Description

BACKGROUND OF THE INVENTION

1. Field of the Invention

This invention relates to improved mixtures of antibacterial and antifungal agents and compositions containing said mixtures. More particularly, it relates to such mixtures which give improved activity against more resistant bacteria such as Pseudomonas aeruginosa.

Prior Art

U.S. Pat. No. 3,239,411, issued Mar. 8, 1966, teaches that various organo-bismuth compounds, such as diphenylbismuth acetate, are effective antibacterial and antifungal agents for use against a wide variety of gram-positive and gram-negative organisms. Similarly, the heavy metal salts of 1-hydroxy-2-pyridinethione are known. See, e.g., U.S. Pat. No. 2,809,971. The use of zinc pyridinethione as an antibacterial agent has been disclosed in various soap, detergent and cosmetic preparations. See, e.g., U.S. Pat. Nos. 3,412,033; 3,281,366; and 3,235,455.

SUMMARY OF THE INVENTION

The present invention is directed toward synergistic combinations of the heavy metal salts of 1-hydroxy-2-pyridinethione and either phenylbismuth acetate, bismuth trichloride, bismuth formic iodide, or bismuth subgallate. This synergism is present in all proportions of these classes of antibacterial compounds. It is most evident in the preferred ratio of from 1:9 to 9:1, the most preferred ratio being 80:20, and the most preferred mixture being diphenylbismuth acetate:zinc 1-hydroxy-2-pyridinethione.

The synergism of these mixtures is evident against a wide variety of bacteria, yeast and fungal species, but it is most impressive against Pseudomonas aeruginosa (Ps.a.), which is extremely difficult to inhibit. Ps.a. is currently a problem in many hospitals due to its inherent resistance to most antibacterial agents. At the same time, the mixtures will also display their synergistic activity against the common organisms such as Staphylococcus epidermidis (S.ep.), Streptococcus faecalis (St. f.), and Escherichia coli (E.c.). Other bacteria which are controlled by the mixture are disclosed hereinafter in the examples.

It has also been found that the above-disclosed combination of antibacterial agents possesses synergistic antibacterial properties whereby a lasting antibacterial and antifungal effect is obtained particularly in soap and non-soap synthetic detergent compositions, and other products where an antibacterial action is desired. Such compositions containing the synergistic combination of the present invention in amounts of from about 0.2% to about 3%, preferably about 1%, are particularly effective.

The term "soap" as used herein is meant to designate alkali metal soaps such as the sodium and potassium salts of the higher fatty acids of naturally occurring plant or animal esters, e.g., palm oil, coconut oil, babassu oil, soybean oil, castor oil, tallow, whale and fish oils, grease and lard and mixtures thereof. Sodium and potassium soaps can be made by direct saponification of the fats and oils or by the neutralization of the fatty acids which are prepared in a separate manufacturing process. Examples of suitable soaps are the sodium, potassium, ammonium and alkylolammonium salts of higher fatty acids (C.sub.10 - C.sub.20). Particularly useful are the sodium and potassium salts of the mixtures of fatty acids derived from coconut oil and tallow, i.e., sodium or potassium tallow and coconut soap.

Anionic synthetic detergents which can be used with the antibacterial combinations of the present invention can be broadly defined as the water-soluble salts, including the alkali metal, ammonium and substituted ammonium salts, of organic sulfuric reaction products having in their molecular structure an alkyl radical containing from about 8 to about 22 carbon atoms and a radical selected from the group consisting of sulfonic acid and sulfuric acid ester radicals.

Important examples of the synthetic detergents which can be used with the compositions of the present invention are the following: alkali metal (e.g., sodium and potassium) ammonium and substituted ammonium (e.g., lower alkyl ammonium) salts of the following: alkyl sulfates, especially those obtained by sulfating the higher alcohols produced by reducing the glycerides of tallow or coconut oil; random paraffin sulfonates, in which the alkyl group contains from about 8 to about 22 carbon atoms, prepared by treating random paraffin hydrocarbons in sulfur dioxide and chlorine in the presence of light followed by treating with a base; branched or linear alkyl benzene sulfonates, in which the alkyl group contains from about 8 to about 18 carbon atoms, preferably from about 10 to about 14 carbon atoms, especially those of the types described in U.S. Pat. No. 2,220,099, and 2,477,383; sodium alkyl glyceryl ether sulfonates, especially those ethers of the higher alcohols derived from tallow and coconut oil; coconut oil fatty acid monoglyceride sulfates and sulfonates; sulfuric acid esters of the reaction product of one mole of a higher fatty alcohol (e.g., tallow or coconut alcohols) and from about 1 to about 6, preferably about 3 moles of ethylene oxide; alkyl phenol ethylene oxide ether sulfates with about 4 units of ethylene oxide per molecule and in which the alkyl radicals contain about 9 carbn atoms; the reaction product of fatty acids esterified with isethionic acid and neutralized with sodium hydroxide where, for example, the fatty acids are derived from coconut oil; fatty acid amides of the methyl taurine in which the fatty acids, for example, are derived from coconut oil; sulfonated olefins of U.S. Pat. No. 3,332,880; and other known others the art, a number being specifically set forth in U.S. Pat. Nos. 2,486,921, 2,486,922 and 2,396,278.

The nonionic synthetic detergents which can be used with the antibacterial combinations of the present invention may be broadly defined as compounds produced by the condensation of alkylene oxide groups (hydrophilic in nature) with an organic hydrophobic compound which may be aliphatic or alkyl-aromatic in nature. The length of the hydrophilic or polyoxyalkylene radical which is condensed with any particular hydrophobic group can be readily adjusted to yield a water-soluble compound having the desired degree of balance between hydrophilic and hydrophobic elements.

For example, a well-known class of nonionic synthetic detergents is made available on the market under the trade name of "Pluronic." These compounds are formed by condensing ethylene oxide with a hydrophobic base formed by the condensation of propylene oxide with propylene glycol. The hydrophobic portion of the molecule which, of course, exhibits water insolubility has a molecular weight of from about 1,500 to about 1,800. The addition of polyoxyethylene radicals to this hydrophobic portion tends to increase the water solubility of the molecule as a whole and the liquid character of the products is retained up to the point where polyoxyethylene content is about 50% of the total weight of the condensation product.

Other suitable nonionic synthetic detergents include:

1. The polyethylene oxide condensates of alkyl phenols, e.g., the condensation products of alkyl phenols having an alkyl group containing from about 6 to 12 carbon atoms in either a straight chain or branched chain configuration, with ethylene oxide, the said ethylene oxide being present in amounts equal to 10 to 60 moles of ethylene oxide per mole of alkyl phenol. The alkyl substituent in such compounds may be derived from polymerized propylene, diisobutylene, octane, or nonane, for example.

2. Those derived from the condensation of ethylene oxide with the product resulting from the reaction of propylene oxide and ethylene diamine -- products which may be varied in composition depending upon the balance between the hydrophobic and hydrophilic elements which is desired. For example, compounds containing from about 40 to about 80% polyoxyethylene by weight and having a molecular weight of from about 5,000 to about 11,000 resulting from the reaction of ethylene oxide groups with a hydrophobic base constituted of the reaction product of ethylene diamine and excess propylene oxide, said base having a molecular weight of the order of 2,500 to 3,000, are satisfactory.

3. The condensation product of aliphatic alcohols having from 8 to 18 carbon atoms, in either straight chain or branched chain configuration, with ethylene oxide, e.g., a coconut alcohol ethylene oxide condensate having from 10 to 30 moles of ethylene oxide per mole of coconut alcohol, the coconut alcohol fraction having from 10 to 14 carbon atoms.

4. Long chain tertiary amine oxides corresponding to the following general formula, R.sub. 1 R.sub. 2 R.sub. 3 N.fwdarw.O, wherein R.sub.1 contains an alkyl, alkenyl or monohydroxy alkyl radical of from about 8 to about 18 carbon atoms from 0 to about 10 ethylene oxide moieties, and from 0 to 1 glyceryl moiety, and R.sub.2 and R.sub.3 contain from 1 to about 3 carbon atoms and from 0 to about 1 hydroxy group, e.g., methyl, ethyl, propyl, hydroxy ethyl, or hydroxy propyl radicals. The arrow in the formula is a conventional representation of a semi-polar bond. Examples of amine oxides suitable for use in this invention include dimethyldodecylamine oxide, oleyldi(2-hydroxyethyl) amine oxide, dimethyloctylamine oxide, dimethyldecylamine oxide, dimethyltetradccylamine oxide, 3,6,9-trioxaheptadecyldiethylamine oxide, di(2-hydroxyethyl)-tetradecylamine oxide, 2-dodecoxyethyldimethylamine oxide, 3-dodecoxy-2-hydroxypropyldi(3-hydroxypropyl)amine oxide, dimethylhexadecylamine oxide.

5. Long chain tertiary phosphine oxides corresponding to the following general formula RR'R"P.fwdarw.O, wherein R contains an alkyl, alkenyl or monohydroxyalkyl radical ranging from 8 to 18 carbon atoms in chain length, from 0 to about 10 ethylene oxide moieties and from 0 to 1 glyceryl moiety and R' and R" are each alkyl or monohydroxyalkyl groups containing from 1 to 3 carbon atoms. The arrow in the formula is a conventional representation of a semipolar bond. Examples of suitable phosphine oxides are:

dodecyldimethylphosphine oxide,

tetradecyldimethylphosphine oxide,

tetradecylmethylethylphosphine oxide,

3,6,9 -trioxaoctadecyldimethylphosphine oxide,

cetyldimethylphosphine oxide,

3-dodecoxy-2-hydroxypropyldi(2-hydroxyethyl)phosphine oxide,

stearyldimethylphosphine oxide,

cetylethylpropylphosphine oxide,

oleyldiethylphosphine oxide,

dodecyldiethylphosphine oxide,

tetradecyldiethylphosphine oxide,

dodecyldipropylphosphine oxide,

dodecyldi(hydroxymethyl)phosphine oxide,

dodecyldi(2-hydroxyethyl)phosphine oxide,

tetradecylmethyl-2hydroxypropylphosphine oxide,

oleyldimethylphosphine oxide,

2-hydroxydodecyldimethylphosphine oxide.

6. Long chain dialkyl sulfoxides containing one short chain alkyl or hydroxy alkyl radical of 1 to about 3 carbon atoms (usually methyl) and one long hydrophobic chain which contains alkyl, alkenyl, hydroxy alkyl, or keto alkyl radicals containing from about 8 to about 20 carbon atoms, from 0 to about 10 ethylene oxide moieties and from 0 to 1 glyceryl moiety. Examples include:

octadecyl methyl sulfoxide, 2-ketotridecyl methyl sulfoxide,

3,6,9-trioxaoctadecyl 2-hydroxyethyl sulfoxide,

dodecyl methyl sulfoxide,

oleyl 3-hydroxy propyl sulfoxide,

tetradecyl methyl sulfoxide,

3-methoxytridecyl methyl sulfoxide

3-hydroxytridecyl methyl sulfoxide,

3-hydroxy-4-dodecoxybutyl methyl sulfoxide.

The zwitterionic synthetic detergents useful with the antibacterial agents of the present invention can be broadly described as derivatives of aliphatic quaternary ammonium, phosphonium, and sulfonium compounds, in which the aliphatic radicals can be straight chain or branched, and wherein one of the aliphatic substituents contains from about 8 to 18 carbon atoms and one contains an anionic water solubilizing group, e.g., carboxy, sulfonate, sulfate, phosphate, or phosphonate. A general formula for these compounds is: ##SPC1##

wherein R.sup.2 contains an alkyl, alkenyl, or hydroxy alkyl radical of from about 8 to about 18 carbon atoms, from 0 to about 10 ethylene oxide moieties and from 0 to 1 glyceryl moiety; Y is selected from the group consisting of nitrogen, phosphorous, and sulfur atoms; R.sup.3 is an alkyl or monohydroxyalkyl group containing 1 to about 3 carbon atoms; x is 1 when Y is a sulfur atom and 2 when Y is a nitrogen or phosphorous atom, R.sup.4 is an alkylene or hydroxyalkylene of from 1 to about 4 carbon atoms and Z is a radical selected from the group consisting of carboxylate, sulfonate, sulfate, phosphonate, and phosphate groups.

Examples include:

4-[N,N-di(2-hydroxyethyl)-N-octadecylammonio]-butane-1-carboxylate;

5-[S-3-hydroxypropyl-S-hexadecylsulfonio] 3-hydroxypentane-1-sulfate;

3-[P,P-diethyl-p-3,6,9-trioxatetradecoxylphosphonio]-2-hydroxy-propane-1-ph osphate;

3-[N,N-dipropyl-N-3-dodecoxy-2-hydroxypropylammonio]-propane-1-phosphonate;

3-(N,N-dimethyl-N-hexadecylammonio)propane-N,N-dimethyl-N-hexadecylammonio) propane-1-sulfonate;

3-(N,N-dimethyl-N-hexadecylammonio)-2-hydroxypropane-1-sulfonate;

4-[N,N-di(2-hydroxyethyl)-N-(2-hydroxydodecyl)ammonio]-butane-1-carboxylate ;

3-[S-ethyl-S-(3-dodecoxy-2-hydroxypropyl)sulfonio]-propane-1-phosphate;

3-[P,P-dimethyl-P-dodecylphosphonio]-propane1-phosphonate; and

5-[N,N-di(3-hydroxypropyl)-N-hexadecylammonio]2-hydroxy-pentane-1-sulfate.

The amphoteric synthetic detergents useful in the present invention can be broadly described as derivatives of aliphatic secondary and tertiary amines in which the aliphatic radical can be straight chain or branched and wherein one of the aliphatic substituents contains from about 8 to about 18 carbon atoms and one contains an anionic water solubilizing group, e.g., carboxy, sulfonate, sulfate, phosphate, or phosphonate. Examples of compounds, falling within this definition are sodium 3-dodecylaminopropionate, sodium 3-dodecylaminopropane sulfonate, dodecyl-.beta.-alanine, N-alkyltaurines such as the one prepared by reacting dodecylamine with sodium isethionate according to the teaching of U.S. Pat. NO. 2,658,072, N-higher alkyl aspartic acids such as those produced according to the teaching of U.S. Pat. No. 2,438,091, and the products sold under the trade name "Miranol" and described in U.S. Pat. No. 2,528,378.

Detergent formulations containing the antibacterial compositions of the present invention can also contain from about 0 to about 90%, preferably from about 10 to about 90% of water-soluble alkaline detergency builder salts, either of the organic or inorganic types. Examples of such builder salts can be found in U.S. Pat. No. 3,336,233, issued Aug. 15, 1967, column 9, lines 29-66, which is incorporated herein by reference.

The detergent formulations can also contain any of the usual adjuvants, diluents, and additives, for example, perfumes, anti-tarnishing agents, anti-redeposition agents, dyes, fluorescers, suds builders, suds depressors and the like without detracting from the advantageous properties of the antibacterial compositions of the present invention.

Examples of diluents which may be incorporated into a synthetic detergent bar in amounts of up to about 80% of the bar include soaps, especially heavy metal insoluble soaps, (metallic salts of higher fatty acids); starches such as cornstarch; and clays such as china clay or fuller's earth. Other diluents include inorganic salts such as sodium and potassium chlorides and sulfates. Such diluents add bulk to the bar and improve its cosmetic properties without impairing its detergent or cohesive properties.

In compositions the antibacterial mixture may tend to react slowly to give the phenylbismuth di(pyridinethione-N-oxide) of the copending application of John D. Curry, application Ser. No. 98,086, filed concurrently herewith now abandoned. Therefore, the shelf life of some compositions containing the mixture of diphenylbismuth acetate and zinc 1-hydroxy-2-pyridinethione may be limited insofar as stability is concerned. The mixture of diphenylbismuth acetate and zinc 1-hydroxy-2-pyridinethione is stable for an indeterminate period of time in buffered solutions such as "pHisoderm." The mixture is also effective when slurried in water or dissolved in an organic solvent. Care, however, should be taken when using the mixture in an organic solvent, since zinc 1-hydroxy-2-pyridinethione when solubilized may have increased toxicity to mammals. This same care should be taken when zinc 1-hydroxy-2-pyridinethione is mixed in alkaline solutions with detergents and other salts containing a sodium ion. Under such circumstances, the zinc 1-hydroxy-2-pyridinethione can be changed to the soluble sodium 1-hydroxy-2-pyridinethione which will display mammalian toxicity.

These precautions as to mammalian toxicity, of course, are irrelevant where contact with mammals is kept to a minimum.

The following examples illustrate the invention.

EXAMPLE I

Diphenylbismuth acetate and 1-hydroxy-2-pyridinethione were tested to determine the minimal inhibitory concentration (MIC) in agar for the two materials and their mixtures against Staphylococcus epidermidis, Streptococcus faecalis, Pseudomonas aeruginosa, and Escherichia coli.

10,000 ppm stock solutions of diphenylbismuth acetate and 1-hydroxy-2-pyridinethione were prepared in dimethyl formamide. The sanitizers were combined in the desired test ratios, mixed thoroughly and added directly to 19 to 20 ml of molten trypticase soy agar to give a series of graded concentrations for each ratio. Thorough rotation of plates assured adequate mixing of the sanitizers before agar solidification. Appropriate control plates containing concentrations of each sanitizer alone as well as plain agar were included. All plates remained at room temperature overnight.

0.1 ml of a diluted 18 hour broth culture of each organism was added directly onto a sterile one-half inch diameter filter disc. The Staphylococcus epidermidis was used at a dilution of 1:1000; the Streptococcus faecalis was used at a dilution of 1:10; the Pseudomonas aeruginosa was used at a dilution of 1:10,000; and the Escherichia coli was used at a dilution of 1:10,000. Sufficient discs were prepared in this manner to inoculate each plate with all organisms. Discs containing bacteria were placed on the agar surfaces, marked in numbered sectors, for approximately 30 minutes and then removed. Plates were incubated 48 hours at 37.degree.C. and then examined for growth.

The following table summarizes the ratios of diphenylbismuth acetate (PBA) to 1-hydroxy-2-pyridinethione (ZPT) tested, the minimal inhibitory concentrations in parts per million of said mixtures and the ratio sum for each mixture. Where the ratio sum is greater than 1, there is antagonism, and where the ratio sum is less than 1, there is synergism, assuming a straight line relationship for activity vs. concentration. The results clearly show synergism for all ratios of the two antibacterial agents.

Table I ______________________________________ Synergism of Several Ratios of PBA and ZPT Against Four Organisms (MIC Test in Agar) ______________________________________ Organism PBA:ZPT MIC (ppm) Ratio Sum* ______________________________________ Staphylococcus 100:0 8.0 1.000 epidermidis 80:20 6.0 0.900 60:40 4.0 0.700 40:60 1.0 0.200 20:80 1.0 0.225 0:100 4.0 1.000 Streptococcus 100:0 10.0 1.000 faecalis 80:20 2.0 0.240 60:40 0.5 0.070 40:60 0.5 0.080 20:80 1.0 1.180 0:100 5.0 1.000 Pseudomonas 100:0 >100 1.000 aeruginosa 80:20 20 0.227 60:40 20 0.253 40:60 20 0.280 20:80 20 0.307 0:100 60 1.000 Escherichia 100:0 >20 1.000 coli 80:20 8.0 0.720 60:40 6.0 0.780 40:60 4.0 0.680 20:80 4.0 0.840 0:100 4.0 1.000 ______________________________________ *Ratio sum> 1 = antagonism Ratio sum < 1 = synergism Calculations according to: Zwart Voorspuiji, A. and Nass, C. Arch. Intern Pharmacodynamie 109:211-28, 1957.

The minimal inhibitory concentrations (MIC) of 80:20 ratios of PBA:ZPT against several other organisms were determined according to the method described in Example I. Diluted broth cultures of the organisms were added directly to agar surfaces with Kline antigen microdroppers instead of using the filter paper discs previously described. Results were as follows:

Organism MIC (ppm) ______________________________________ Staphylococcus aureus 0.2 Streptococcus species 0.1 Sarcina lutea 0.8 Diphtheroid species 0.4 Serratia marcescens 8.0 Klebsiella pneumoniae 8.0 Enterobacter aerogenes 8.0 Corynebacterium acnes* 1.0 Pityrosporum ovale** 10.0 Aspergellus niger*** 30.0 Microsporum gypseum*** 1.0 ______________________________________ *Brain heart infusion agar + 1% glucose used as growth medium (anaerobic) **Trypticase soy agar + 0.1% of a 95:5 ratio of oleic:palmitic acid used as growth medium ***Modified gradient plate technique of Hunt and Sardham used (Applied Microbiology 17 2:329-30, 1969)

These results emphasize the broad spectrum of antimicrobial activity present in the 80:20 PBA:ZPT sanitizer system.

EXAMPLE II

The following test method was used in this example: Cornified epidermis was obtained from the plantar surfaces of human volunteers by cutting sheets of uniform thickness (0.4 mm.) with a dermitome. Discs, 6 mm. in diameter, were cut from the sheets with a number 2 cork borer. A 2.5% stock solution of "pHisoderm" and 10,000 parts per million stock solutions of diphenylbismuth acetate (PBA) and zinc 1-hydroxy-2-pyridinethione (ZPT) in dimethylformamide (DMF) were prepared. Small, screwcapped vials held 20 ml. of the "pHisoderm" solution containing either the sanitizers along or in combination in concentrations ranging from 0.5% to 2% (125 to 300 ppm). A control was also included.

The required number of discs were added to the vials which then were mechanically agitated for 10 minutes in a 50.degree.C. water bath. The vial contents were then transferred to a small beaker where the washing liquid was removed by suction and three 30 ml. distilled water rinses were applied with suction removal of the rinse water. The discs were then dried for 2 hours on paper towels covered with a plexiglass shield to prevent air contamination. The dry discs were placed on the surface of 15 ml. of solidified trypticase soy agar (TSA) in a Petri dish (no more than two discs/dish). A 1:10,000 dilution of each of the test organisms in TSA at 50.degree.C. was prepared. Each Petri dish was overlaid with 10 ml. of agar seeded with one of the organisms. After agar solidification, the dishes were refrigerated overnight to allow diffusion of any sanitizer away from the disc into the medium. The following day, the dishes were placed in a 37.degree.C. incubator for 24 hours.

The diameter of any clear zones of bacterial growth inhibition were measured in mm. including the diameter of the disc. A clear zone is indicative of sanitizer retention on excised stratum corneum after the washing and rinsing process. Synergism of two compounds is evident if a zone produced by a combination is greater than the zone produced by the same concentration of both compounds tested separately.

The diameters of zones around discs washed in the stated concentrations of either PBA, ZPT, or combinations of these agents are presented in Table II for two test organisms -- Escherichia coli and Pseudomonas aeruginosa. The presence or absence of synergism is also indicated.

Table II ______________________________________ Synergism of PBA:ZPT Combinations Against Two Gram-negative Bacteria in the Human Corneum Disc Test ______________________________________ % Concentration in 2.5% pHisoderm Test Organisms PBA ZPT Escherichia Pseudomonas coli aeruginosa ______________________________________ 0.5 -- 10* 0 1.0 -- 12 0 1.5 -- 12 0 2.0 -- 12 0 -- 0.5 8 0 -- 1.0 9 0 -- 1.5 9 0 -- 2.0 11.5 0 0.5 0.5 23 + 11.5 + 1.0 0.5 24 + 20 + 0.5 1.0 18 + 11.5 + 1.0 1.0 23 + 14.5 + 1.5 0.5 22 + 13.5 + 0.5 1.5 21 + 15 + "pHisoderm" control 0 0 ______________________________________ *All values are total zone diameters in mm. (including 6 mm. disc) +Synergism

As can be seen, synergism was realized with every combination of PBA and ZPT tested against both organisms, but the most pronounced effect was found with Pseudomonas aeruginosa.

EXAMPLE III

The following test method was utilized:

PBA and ZPT were prepared in "pHisoderm" in the following concentrations:

0.01% PBA:

0.01% zpt;

0.0075% pba + 0.0025% zpt;

0.005% pba + 0.005% zpt; and

0.0025% PBA + 0.0075% ZPT.

These concentrations were prepared by adding the dry sanitizer powders directly to "pHisoderm" and mixing thoroughly with a mechanical mixer. The final product for a given test was distributed in 12 small plastic bottles for use by each test subject at home and two larger bottles for laboratory handwashings.

Groups of 12 subjects were employed in the testing of each product. They were chosen at random from a large group of available subjects who use non-sanitizer products exclusively for personal hygiene. During the three-day testing period, each subject used only the assigned product for hand cleansing. Three regimented washings were required daily in the laboratory as follows:

a. The hands were moistened under 100.degree.F. running tap water.

b. The product was squeezed from a plastic bottle into the palm in an amount approximately the size of a 25 cent piece.

c. The product was distributed over the hands and lather worked for 90 seconds.

d. The hands were then rinsed under running tap water for 30 seconds.

Ad libitum washings were done at home. On day 1, the test product was given to the panelists for home use and they completed the three standard washes for that day. The same schedule was followed the second day and on the morning of the third day, quantitative determinations of the bacterial hand flora were made as follows:

a. Four successive handwashings were performed as described above using a "blank" bar soap containing no antibacterial agents.

b. A fifth standardized washing was done in a basin containing 1 liter of sterile distilled water with careful rinsing in this basin.

c. Aliquots were taken from the thoroughly mixed basin contents, added to 30 ml. of sterile distilled water in a membrane funnel, and passed through sterile membrane filters with vacuum suction.

d. The filters were incubated on pads saturated with 2X concentrated trypticase soy broth plus 10% horse serum and 1% Tween 80 in plastic dishes for 48 hours at 37.degree.C.

e. Colonies appearing on the filters were counted and these numbers multiplied by the appropriate dilution factor to determine the number of bacteria/liter in the fifth basin.

The numbers of colonies for each panelist were converted to logarithms to minimize unusually high or low counts. These values were averaged to determine the mean log of the fifth basin bacterial count. Log percent reduction for each subject was determined using the log of 1.3 .times. 10.sup.6, or 6.1184, as an average for the fifth basin bacterial count obtained from more than 500 handwashings by nonantibacterial soap users. These values were then averaged to obtain the mean log percent reduction.

Table III ______________________________________ Synergism of Ratios of PBA:ZPT in Handwashing Tests ______________________________________ Sanitizer Concentrations Mean Log in "Phisoderm"* Mean Log % Reduction ______________________________________ 0.01% PBA 5.7942 52.60 0.01% ZPT 5.7764 0.0075% PBA + 0.0025% ZPT 5.3790 81.78 0.005% PBA + 0.005% ZPT 5.5987 69.78 0.0025% PBA + 0.0075% ZPT 5.6258 67.83 ______________________________________ *Two-day exposures

As can be seen from the above table, the mixture of antibacterial agents gave synergistically better performance than the individual components. This test confirms in vivo the synergism demonstrated in the previous in vitro tests.

Five separate handwashing tests of 1% PBA:ZPT (80:20) in "Phisoderm" have shown the following results:

Log % Reduction Mean Log ______________________________________ 99.2 4.0236 98.35 4.3360 98.12 4.3933 99.03 4.1060 97.3 4.5490 ______________________________________

These results demonstrate the skin degerming effectiveness of PBA:ZPT under conditions of actual use by human subjects.

EXAMPLE IV

Using the test procedure of Example I with Kline antigen microdroppers for delivery of the inoculum to the agar surfaces, the minimal inhibitory concentration was determined for an 80:20 mixture of PBA:ZPT in a water slurry containing no solvent against the following indicated organisms:

Table IV ______________________________________ Organism MIC (ppm) ______________________________________ Staphylococcus aureus 0.5 Escherichia coli 6 Pseudomonas aeruginosa 40 Serratia marcescens 8 Klebsiella pneumoniae 8 Enterobacter aerogenes 10 ______________________________________

EXAMPLE V

Shampoo Compositions ______________________________________ Composition No. 1 No. 2 No. 3 ______________________________________ Sulfated coconut fatty 23 23 alcohol -- sodium salt Sodium stearate 8.7 8.7 Sodium alkyl glyceryl 28.3 ether sulfonate.sup.1 Sodium acyl 5.0 sarcosinate.sup.2 Sodium sulfate 0.8 0.8 2.6 Sodium chloride 6.6 Trisodium phosphate 2.1 2.1 Diethanolamide of 2.0 coconut fatty acids Acetylated lanolin 1.0 1.0 1.0 Phenyl mercuric 0.113 0.113 0.0035 acetate.sup.3 Perfume 1.0 1.0 0.4 80:20 mixture of 0.5 1.0 1.5 PBA:ZPT Water (make up balance) pH 7.7 7.7 7.4 ______________________________________ .sup.1 Alkyl radicals derived from fatty alcohol, 25.3% from coconut and 3% from tallow. .sup.2 Acyl radicals derived from coconut fatty acids. .sup.3 31/2% solution in oleic acid in No. 1 and No. 2.

Composition No. 4 Percent ______________________________________ Dimethyl coconut.sup.1 amine oxide 8.0 Disodium lauryl beta-iminodipropionate 5.0 Sodium coconut.sup.1 sulfate 4.0 Coconut.sup.2 diethanolamide 1.0 80:20 mixture of PBA:ZPT 1.0 Perfume 0.5 Color Less than 0.01 Citric acid to adjust pH to 7.5 Water Balance ______________________________________ .sup.1 The alkyl radical is derived from middle cut coconut alcohol and has approximately the following chain length composition: 2% C.sub.10, 66 C.sub.12, 23% C.sub.14, and 9% C.sub.16. .sup.2 Wholecut.

COMPOSITION NO. 5

A shampoo composition is obtained by uniformly mixing together the following ingredients:

4% triethanolamine salt of the sulfated condensation product of 3 moles of ethynene oxide and one mole of coconut oil fatty alcohol having the following chain length distribution: 2% C.sub.10, 66% C.sub. 12, 23% C.sub.14, and 9% C.sub.16.

10% triethanolamine N-acyl sarcosinate, the acyl radicals being derived from coconut oil fatty acids and having the following chain length distribution: 10% C.sub.8.sub.-10, 48% C.sub.12, 21% C.sub.14, 10% C.sub.16, and 11% C.sub.18. 3% monoethanolamide of coconut oil fatty acids having the following chain length distribution: 16% C.sub.6.sub.-10, 48% C.sub.12, 17% C.sub.14, 9% C.sub.16, and 10% C.sub.18.

1% 80:20 mixture of PBA:ZPT.

3% diethanolamide of coconut oil fatty acids having the following chain length distribution: 16% C.sub.6.sub.-10, 48% C.sub.12, 17% C.sub.14, 9% C.sub.16, and 10% C.sub.18.

0.65% ethylenediamine tetraacetic acid (as its partial triethanolammonium salt)

7% ethanol

0.75% methyl cellulose, a 2% solution of which has a viscosity of 4000 cps. at 68.degree.F. and a gel point of 140.degree.F.

0.15% sodium sulfite

0.007% phenyl mercuric acetate

0.75% perfume

balance, water.

Shampoo formulations containing 80:20 mixtures of PBA:ZPT are desirable since they will control dandruff.

EXAMPLE VI

Personal Use Detergent Lotion ______________________________________ Composition No. 6 Percent ______________________________________ Potassium coconut.sup.1 glyceryl ether 3.0 sulfonate (about 23% diglyceryl and the balance substantially all monoglyceryl Sodium coconut.sup.1 glyceryl ether 4.0 sulfonate (diglyceryl and monoglyceryl content as above Sodium tallow glyceryl ether 3.0 sulfonate (diglyceryl and monoglyceryl content as above; the tallow alkyl radicals correspond to those of sub- stantially saturated tallow alcohols containing approximately 2% C.sub.14, 32% C.sub.16, and 60% C.sub.18 Coconut.sup.1 dimethylamine oxide 5.0 Sodium salt of sulfated condensation 2.0 product of one mole of nonylphenol with 4 moles ethylene oxide Potassium pyrophosphate 1.0 80:20 mixture of PBA:ZPT 2.0 Sodium chloride (in addition to 3.0 that from detergents) Sodium toluene sulfonate 2.5 Sodium carboxymethylcellulose 0.3 (degree of substitution 0.65-0.95; viscosity of 1% soln., 1000-2800 cps. at 25.degree.C.) Acrylamide polymer (contains 5-10 0.1 mole percent acrylic acid radicals; monomer is less than 0.05%; viscosity of a 0.5% soln. is about 10-15 centipoises at 25.degree.C.) Salts (sodium and potassium chloride 1-2 and sulfate from detergents) Water Balance ______________________________________ .sup.1 Coconut indicates alkyl radicals corresponding to those of middle cut coconut fatty alcohol containing approximately 2% C.sub.10, 66% C.sub.12, 23% C.sub.14, and 9% C.sub.16.

EXAMPLE VII

Cream Shampoo ______________________________________ Composition Percent ______________________________________ Sodium coconut glyceryl ether 14.8 sulfonate (about 29% diglyceryl and the balance substantially Sodium tallow glyceryl ether sulfonate 2.0 (about 28% diglyceryl and the balance substantially monoglyceryl) Sodium chloride 6.7 Sodium sulfate 3.5 Sodium N-lauroyl sarcosinate 3.0 80:20 mixture of PBA:ZPT 2.0 coconut.sup.1 diethanolamine 0.5 Acetylated lanolin 1.0 Perfume 0.4 Water Balance ______________________________________ .sup.1 2% C.sub.10, 66% C.sub.12, 23% C.sub.14, and 9% C.sub.16.

A milled toilet detergent bar is prepared in accordance with methods known and used in the art and having the following composition:

Percent Sodium alkyl glyceryl ether sulfonate 8.0 (alkyl group derived from the middle- cut.sup.1 of alcohols obtained by catalytic reduction of coconut oil) Potassium alkyl sulfate (alkyl group derived from the middle cut.sup.1 of 20.0 alcohols obtained by catalytic reduction of coconut oil) Magnesium soap of 80:20 tallow: 17.0 coconut fatty acids Inorganic salts (sodium and potassium 32.0 chlorides and sulfates) 80:20 mixture of PBA:ZPT 1.0 balance Water and minors to 100 .sup.1 Middle-cut coconut alcohols having a chain length distribution substantially as follows: 2% C.sub.10, 66% C.sub.12, 23% C.sub.14 and 9% C.sub.16.

This bar cleans well and exhibits good odor reducing properties evidencing antibacterial effectiveness. It reduces the number of bacteria on the skin and does not discolor significantly.

A granular built synthetic detergent composition having the following formulation can be prepared and the antibacterial compositions of the present invention can be incorporated therein.

______________________________________ Percent Sodium dodecylbenzene sulfonate 17.5 Sodium tripolyphosphate 50.0 Sodium sulfate 14.0 Sodium silicate (SiO.sub.2 :Na.sub.2 O=2:1) 7.0 80:20 mixture PBA:ZPT 3.0 balance Water and minors to 100 ______________________________________

This composition, in addition to performing well in its cleaning capacity, imparts considerable antibacterial and antifungal activity to fabrics cleansed in its solution.

Substantially equivalent results are obtained, i.e., good cleaning and good odor reducing properties when the sodium dodecylbenzene sulfonate of Example IV is replaced, on an equal weight basis, by the following:

sodium tallow alkyl sulfate;

potassium coconut alkyl glyceryl ether sulfonate;

sodium salt of randomly sulfonated paraffin containing an average of 15.2 carbon atoms;

ammonium tridecyl sulfate;

condensation product of octyl phenol with 15 moles of ethylene oxide per mole of octyl phenol;

dimethyldodecylamine oxide;

dodecyldimethylphosphine oxide;

tetradecyl methyl sulfoxide;

3-(N,N-dimethyl-N-hexadecylammonio)propane-1-sulfonate;

3-dodecylaminopropionate; and

dodecyl-.beta.-alanine.

The invention has been described above in conjunction with toilet and laundry detergents. It will be obvious to those skilled in the art, however, that the antibacterial compositions of the present invention can also be beneficially employed in such products as shampoos, foot powders, antiseptic ointments, cosmetic products and the like.

A fabric softening composition having the following formula gives good antibacterial and antifungal protection.

______________________________________ Percent Dialkyl dimethylammonium chloride 6 (alkyl groups are derived from tallow) Alkyl phenol polyethyleneoxide 1.5 (alkyl groups average C.sub.15 and 20 moles of ethyleneoxide) Color and perfume 0.3 80:20 mixture of PBA:ZPT 1.0 Water balance ______________________________________

When in any of the above examples I-VII either bismuth trichloride, bismuth formic iodide, or bismuth subgallate are substituted for the diphenylbismuth acetate, and/or the cadmium, cupric, ferrous, ferric, manganese, mercuric, silver, antimonous, cobaltous, lead, bismuth, auric, mercurous, arsenic, or nickel salts of 1-hydroxy-2-pyridinethione are substituted for the zinc 1-hydroxy-2-pyridinethione, substantially equivalent results are obtained in that the mixtures exhibit a synergistic antibacterial and antifungal activity.

Claims

What is claimed is:

1. An antibacterial and antifungal composition, active against Pseudomonus aeruginosa and Escherichia coli bacteria, said composition containing a mixture of:

A. zinc 1-hydroxy-2-pyridinethione; and

B. diphenylbismuth acetate in the ratio of (A) to (B) of from about 1:9 to about 9:1.

2. An antibacterial and antifungal composition containing a mixture of:

A. zinc 1-hydroxy-2-pyridinethione; and

B. diphenylbismuth acetate in a ratio of (A) to (B) of from about 1:4 to about 4:1.