US3629414A - Antibacterial and synergistic antifungal compositions - Google Patents

Abstract

COMPOSITONS AND PROCESS UTLIZING A COMBINATION OF NYSTATIN AND AN ALKYL ISOQUINOLINIUM SALT WHICH COMBINATION WHEN USED TOPICALLY SHOWS ANTIBACTERIAL AND SYNERGISTIC ANTIFUNGTAL ACTIVITY.

Description

United States Patent Otfice 3,629,414 Patented Dec. 21, 1971 US. Cl. 424-120 2 Claims ABSTRACT OF THE DISCLOSURE Composition and process utilizing a combination of nystatin and an alkyl isoquinolinium salt which combination when used topically shows antibacterial and synergistic antifungal activity.

This is a continuation-in-part of co-pending U.S. application Ser. No. 700,006 filed Jan. 24, 1968 and now abandoned which in turn is a continuation-in-part of US. application Ser. No. 526,384 filed Feb. 10, 1966, and now abandoned.

The present invention relates to topical antibacterial and synergistic antifungal compositions. In one of its more particular aspects, it relates to novel compositions comprising nystatin and an alkyl isoquinolinium compound which show a remarkable antibacterial and synergistic antifungal activity. In another aspect it relates to an improved process for treating topical fungal and bacterial infections using the hereinabove noted compositions.

It is an object of the present invention to provide novel combinations of compounds which exert synergistic antifungal activity in mammals such as rabbits, mice, dogs and the like. It is another object to provide such compositions which show both antibacterial and antiiungal activity when used topically in such hosts as noted above. Other objects will be elucidated from the ensuing disclosure and the claims appended thereto.

Nystatin is an antibiotic substance isolated from cultures of Streptomyces noursez', the exact chemical struc ture of which has not yet been fully determined. This remarkable compound is known in the art of dermatology to be highly effective in combating monilial infections caused by the organism Candida and particularly Candida albicans. In addition to its therapeutic effectiveness, this material is relatively nontoxic and is free from acquired resistance problems.

As effective as nystatin has been found to be, it has now unexpectedly been discovered that a novel combination of nystatin and an alkyl isoquinolinium compound exerts a remarkable synergistic antifungal activity toward the nystatin in addition to its use as an antibacterial material. An explanation of why the nystatin antifungal activity is increased by the addition thereto of these compounds is not yet available. However, it is believed that somehow the permeability of the fungus cell membrane is changed and that this change in membrane permeability permits easier transport of the antifungal material into the cell with resultant faster cidal activity.

In addition to providing a synergistic antifungal activity in combination with nystatin, the alkyl isoquinolinium compounds of the present invention have been found to exert a broad antibacterial activity. In this regard the alkyl isoquinolinium compounds have been found effective against such bacterial organisms as Staphylococcus aureus, ovate. Thus an extremely valuable and effective therapeutic antifungal and antibacterial composition is achieved.

The compositions of the present invention usually contain from about 40,000 units nystatin per gram of composition to about 400,000 units nystatin per gram of composi tion with a preferable nystatin concentration of about 120,000 units per gram of composition.

The alkyl isoquinolinium compounds of this invention are quaternary ammonium salts having the structure where R is an alkyl group or a mixture of alkyl groups of from about 8 to about 18 carbon atoms and X is a salt-forming anion such as Cl, Br, SO and the like. A preferable compound of this type is alkyl isoquinolinium bromide which is known commercially as Alacsan Libwherein R as defined above is a mixture of alkyl groups as follows: C 50%, C 30%, C -17% and C3C13-3%.

One of the remarkable aspects of the present invention is the concentration at which the alkyl isoquinolinium salts have been found to be effective in exerting its synergistic activity in conjunction with nystatin. In this respect the optimum concentration of these salts has been found to be as low as about 0.1% by weight. Prior art compositions involving the use of a quinoline compound alone have usually been prepared in a concentration of about 3% by weight. Thus, the salts of the present invention may be used at about $4 the concentration of the prior art compounds. However, the concentration may be increased to provide for antibacterial activity as well as synergistic antifungal activity. In this respect it has been found that from about 0.1% by weight to about 3.0% by Weight of the alkyl isoquinolinium salt may be used in the practice of the present invention with a preferable range of from about 0.1% by Weight to about 1.0% by weight.

The compositions of the present invention may be prepared in the form of ointments, lotions and creams. The ointment form of the composition usually utilizes a nonaqueous base material. This base material may be any of the various nonaqueous vehicles utilized by those experienced in the art of dermatology such as, for example, petrolatum, mineral oil, corn oil, and the like. In addition to utilizing these materials alone as the base vehicle for the present composition, various other additives may be used in combination therewith. It has been found particularly advantageous to utilize, as a base additive, a material such as a modified montmorillonite. This is an argillaceous material which is the result of a cation exchange reaction between an organic base and bentonite. These additives enable the obtention of a gel base from a liquid organic material such as mineral oil. Certain of the modified clay additives also impart a thixotropic character to the ointment base.

In addition to ointments, the nystatin-alkyl isoquinolinium salt compositions of the present invention may be utilized in the form of aqueous suspensions. These aqueous suspensions are usually used as lotions. In another useful form the novel combination is combined with various adjuvants to form a cream. In this application the nystatin suspension may be combined with a minor amount of a hydrophobic material to achieve the desired cream form.

In addition to the above ingredients, various other medicaments and adjuvants may be added to the compositions of the present invention. The medicaments may include anti-inflammatory steroids such as hydrocortisone or prednisolone, skin softeners, such as isopropyl myristate, and the like. In this respect hydrocortisone, for example. may be present in a proportion of from about 0.25% to about 5% by weight and preferably at about 0.5% by weight. Because of the variation in potency of the anti-inflammatory steroids, the concentration thereof must be varied according to the particular steroid used.

When the nystatin is used in the form of an aqueous suspension, the compositions of the present invention are preferably adjusted to a pH range of from about 4 to about 6. Such pH adjustment may be accomplished by the use of any of the various topically and pharmaceutically acceptable acids and bases.

In addition to the above medicaments and adjuvants which may be added to the compositions of the present invention, various preservatives such as propylparaben, methylparaben and sorbic acid may also advantageously be added to the present compositions. In this same respect various wetting agents, thickening agents and other adjuvants may be added in order to achieve the physical constitution and elegance desired for the present compositions.

The compositions of the present invention have been found to be useful in treating certain dermatological infections and as such the compositions simply act as bactericides and fungicides, that is, various type growths are arrested and sterilized. Particularly, the compositions of the present invention have been found to exert their synergistic antifungal activity toward the organism Candida albicans. In testing for antifungal activity this organism has been found to be fairly representative and any cidal activity against Candida albicans is indicative of the general antifungal activity of the particular composi tion. In this regard compositions utilizing nystatin alone have been found to be incapable of cidal activity toward a certain culture of Candida albicans for a time interval of at least four hours. Moreover, an alkyl isoquinolinium compound alone is incapable of such cidal activity for a positions. These examples however we not to be construed as placing any limitation on the present invention except as in the present disclosure and the claims appended thereto.

EXAMPLES 1 TO 16 In the following examples ointments were prepared, using a petrolatum base, to contain the constituents indicated in the table. These various compositions were tested for antifungal and antibacterial activity by means of a modified speed-of-kill test and the rate of cidal activity was used as an indication of effectiveness.

The test procedure was performed by weighing aseptically 1.0 g. of each sample on sterile paper discs which were placed into 2ounce sterile jars. To the jars, 5.0 ml. of sterile saline test solution U.S.P. was gently added and the jars were placed in a 37 C. water bath. This was followed by the addition of 0.5 ml. of the culture indicated in the table. Approximate uniformity of inoculum was obtained by growing the culture in appropriate medium (Fluid Sabouraud Medium for Candida albicans and Fluid Thioglycollate Medium for Staphylococcus aureus) prior to the addition to the sample. By means of a sterile platinum transfer loop a small amount of each sample was then transferred at the particular time intervals indicated in the table to 100 ml. of suitable medium as indicated above and incubated at 32 C. for 48 hours. After this incubation period the fluid was examined for the presence of organism growth. The table indicates the results of such tests. A positive sign indicates an observed growth of one or more colonies of the indicated organism. A negative sign indicates the absence of the indicated organism.

TABLE Composition Alkyl iso- Exposure time in minutes Nystatin bromide Organism 0 15 30 60 120 240 480 Example:

1 3 0 0 Candida albicans 40, 000(1) 0 Candida alhicans -t- 3. 01.3) 0 Candida albicans" 4 400 000(10) 0 Candida alflicansfl 5. 800,000(20) 0 Candida nlhicuns b. 0 0.1 Candida nlbicans- -t- 7 0 1. t) Candida albicans.

0 3.0 Candida CllhfCtHML. u U 6.0 Candida alhicans E 10,, 40, 000(1) 0.1 Candida albicuna. -lll 40, 000(1) 3. 0 Candida nlhicam" -iii, .r 120,000(3) 1.0 Candida albicflns" V V r U 0. l Candida albicans 7 40 000(1 3.0 Candida albimns 15, 120,0(l0t3) 0 Staphylococcus uurcus. *5- 16... 120,000t3) 1.0 Staphylococcus uurrm.. -lll Nystatin expressed in units per gram and percent by Weight; alkyl isoquinoliniurn exprvssw'l in percent by Weight.

9 Mixture of alkyl groupsl5 C 30% Cu, 17% Cut and 3% Gs C 3 Control-ointment base.

period of at least 120 minutes. In startling contrast to this, it has been found that by including the alkyl isoquinolinium salt with the nystatin the same culture of Candida albicans can be sterilized in a time interval of as little as 5 minutes.

The compositions of the present invention are useful in treating fungal and bacterial infections, and as such, the compositions are convenient for topical application. As used herein, such topical use entails the application of the composition directly to the infected area as dis tinguished from a systemic utilization of a particular medicament. in regard to frequency and amount of application, this, of course. depends on the concentration of the medicament, the relative efiiciency of the composition and the severity of the infection. This facet of the present invention is entirely within the scope and discretion of one skilled in the art of dermatology and particularly one skilled in treating fungal and bacterial infections.

The following examples will illustrate the method of preparation and the compositions of the present invention as well as the remarkable synergistic activity of such conl- 5 6 where R is a mixture of alkyl groups of from about 8 to References Cited about 18 carbon atoms.

2. An antibacterial and synergistic antifungal composi- UNITED STATES PATENTS tion comprising about 120,000 units per gram of nystatin 2,435,458 2/1948 Mosher 424258 and about 1.0% by weight of the alkyl isoquinolinium 5 bromide having the formula OTHER REFERENCES Chemical Abstracts 41: 7667b (1947). Chemical Abstracts 43: 3884i to 3885b (1949). N.N.D., New and Nonofficial Drugs, J. B. Lippincott 10 Co., Philadelphia, Pa., 1964, pp. 138 and 139 Merck Index, 7th Edition, Merck & Co., Inc., Rahway, Br N1, 1960, p. 582.

JEROME D. GOLDBERG, Primary Examiner 1 where R is alkyl groups of from about 8 to 18 carbon 5 US. Cl. X.R. atoms. 424-258