United States Patent (19) 11) 4,430,325 Gaffar et al. 45) Feb. 7, 1984 54 TOPCAL TREATMENT OF SKN LESIONS OTHER PUBLICATIONS (75) Inventors: Abdul Gaffar; Calvin B. Davis, both of Somerset, N.J. Handbook of Non-prescription Drugs, 5th Ed., 1977, pp. 306, 307 & 347. 73) Assignee: Colgate-Palmolive Company, New York, N.Y. Primary Examiner-Leonard Schenkman (21) Appl. No.: 333,587 Attorney, Agent, or Firm-Herbert S. Sylvester; Murray M. Grill; John A. Stemwedel 22 Filed: Dec. 23, 1981 (57) ABSTRACT 51 Int. Cl......................................... A61K 33/42 52) U.S. C. .................................................... 424/128 A dermatological composition and method for treating (58) Field of Search ......................................... 424/128 skin lesions employing a peroxydiphosphate salt, such as the tetrapotassium salt, as the essential therapeuti 56) References Cited cally active agent. U.S. PATENT DOCUMENTS 4,041,149 8/1977 Gaffar et al. .......................... 424/57 3 Claims, No Drawings 4,430,325 1. 2 relatively abbreviated shelf-life, with loss of its ability to TOPCAL TREATMENT OF SKN LES ONS release active oxygen, protanto reduces its therapeutic value. This invention relates to topical compositions and It is an object of this invention to provide composi methods for the treatment of skin lesions employing a tions and methods for the topical treatment of skin le novel and improved compound as the active therapeu sions which will not be subject to one or more of the tic agent. above deficiencies and disadvantages. Other objects and A great many topical therapeutic agents have been advantages will appear as the description proceeds. previously proposed for the treatment (alleviation, and In accordance with certain of its aspects, this inven /or healing) of skin lesions associated with burns, vari 10 tion includes the provision of a dermatological compo cose ulcers, sycosis vulgaris, seborrhea and acne. Illus sition for treating skin lesions comprising a safe and tratively, U.S. Pat. No. 4,126,681 of Nov. 21, 1978 is therapeutically effective amount of a peroxidiphosphate directed to the use of acetylsalicylic acid (aspirin) as salt (PDP), especially the tetrapotassium salt (KPDP), such agent, and U.S. Pat. No. 4,261,982 of Apr. 14, 1981 and method comprising topically applying such compo describes prior art disclosing as such agents various 15 sition to the afflicted situs. types of zinc salts and antibiotics such as tetracyclin, In contrast to benzoyl peroxide compositions, the erythromycin, lindomycin and clindamycin, and pro PDP compositions of this invention are vastly more poses the use of zinc and erythromycin combinations stable in storage, especially at elevated temperatures, and zinc erythromycin compounds. are readily activated by cysteine to liberate active oxy One of the most widely, if not the most widely, used 20 gen in situ at the situs of the skin lesion, and produce topical therapeutic agents for treating skin lesions has little or no allergic or irritative skin reactions. The ac been benzoyl peroxide. U.S. Pat. No. 4,163,800 of Aug. tive PDP therapeutic agents in the present compositions 7, 1979, in column 1, line 6 to column 2, line 33 discusses are perse substantially more stable in storage than ben skin conditions, diseases and lesions treatable with ben zoyl peroxide. In U.S. Pat. No. 4,041,149 issued Aug. 9, zoyl peroxide, its beneficial effects, and the undesirable 25 1977 to Maria Gaffar, Abdul Gaffar (co-applicant irritation problems and side effects associated with its herein) and John Hauschild directed to anti-odor oral use such as excessive drying, heavy scaling, edema, compositions containing less than 3 wt.% of PDP as the burning, peeling, redness, excessive erythema, allergic active anti-odor agent, the preferred KPDP is described contact dermatitis, and sensitization reactions, which as a stable odorless, finely divided, free-flowing, white, discussion is incorporated herein by reference thereto. 30 non-hygroscopic crystalline solid having a molecular The latter patent is directed to the reduction of such weight of 346.35 and an active oxygen content of 4.6%. skin irritation problems by applying the benzoyl perox It is 47-51% water-soluble at 0-61C., but insoluble in ide in conjunction with certain guanidine compounds. common solvents such as acetonitrile, alcohols, ethers, This expedient of course complicates and increases the ketones, dimethyl formamide, dimethyl sulfoxide, and cost of manufacturing the preparation, requiring as it 35 the like. A 2% aqueous solution has a pH of about 9.6 does various tests and controls to arrive at selection of and a saturated solution thereof a pH of about 10.9. A the particular guanidine compound, optimum ratios of 10% solution in water at 25 C. showed no active oxy benzoyl peroxide and guanidine compound, and selec gen loss after four months; and at 50 C. a 10% solution tion of excipients including vehicles, carriers and/or showed an active oxygen loss of 3% in 6 months. solvents compatible with both components which, fur Further, the above-described substantial water-solu ther, are insoluble and must be suspended in water. bility of these PDP agents provide further advantages There is moreover another highly troublesome prob relative to benzoyl peroxide agents with respect to costs lem involved in the preparation, storage and marketing of vehicle and processing, minimization of skin irrita of benzoyl peroxide preparations, namely the sensitivity tion, incompatibilities of components, and the like, in of the benzoyl peroxide to other conventional ingredi 45 permitting use of water as the sole or major solvent, ents or excipients in the preparation leading to more or vehicle or carrier. less significant degradation of, and loss of oxidizing Any of the alkali metal, alkaline earth metal, metal or activity of, the benzoyl peroxide in storage, especially at ammonium peroxydiphosphates or their corresponding elevated temperatures. This problem is recognized in acid salts that are water-soluble to the extent of about the art, as see the article by Bollinger et al entitled 50 0.001 weight percent can be used in the compositions of "Benzoyl Peroxide Stability in Pharmaceutical Gel this invention. Examples of these are tetrapotassium Preparations', J. Pharm. Sciences 66 No. 5, May 1977, peroxydiphosphate (K4P2O8), tetralithium peroxydi 718-722. This article describing an investigation "to phosphate (LiAP2O8), tetrasodium peroxydiphosphate evaluate various parameters regarding the storage sta (Na4P2O8), tripotassium monosodium peroxydiphos bility of benzoyl peroxide in pharmaceutical gel formu 55 phate (K3NaP2O3), dipotassium disodium peroxydi lations' ends with the statement "In general, the results phosphate (K2Na2P2O8), monopotassium trisodium of this investigation demonstrated that the stability of peroxydiphosphate (KNa3P2O8), monopotassium mon benzoyl peroxide in pharmaceutical gel preparations is osodium dihydrogen peroxydiphosphate (KNaH2 strongly influenced by the chemical makeup of the P2O8), trilithium monopotassium peroxydiphosphate formulations and, secondarily, by the storage tempera (LisKP2O8), dilithium dipotassium peroxydiphosphate ture due to increased reactivity”. The benzoyl peroxide (Li2K2P2O8), monolithium tripotassium peroxydiphos functions at least in part by a mechanism involving phate (LiK3P2O8), trilithium monosodium peroxydi reaction with and/or decomposition by cysteine in the phosphate (Li3NaP2O8), dilithium disodium peroxydi skin, with liberation of oxygen. Bacterial proteins are phosphate (Li2Na2P2O3), monolithium trisodium perox thus oxidized, the oxidization thus exerting both anti 65 ydiphosphate (LiNa3P2O8), monolithium monosodium bacterial and comedolytic activity, especially valuable dihydrogen peroxydiphosphate (LiNaH2P2O8), and in the treatment of acne and acneiform skin disorders. monolithium monopotassium dihydrogen peroxydi Degradation of the benzoyl peroxide in storage, i.e. its phosphate (LiKH2P2O3), in addition to dizinc peroxydi 4,430,325 3 4. phosphate (Zn2P2O8), tetraammonium peroxydiphos One or a mixture of humectants may be included, phate dihydrate (NH4)4P2O82H2O), and the acid salts of preferably in proportions of about 5 to about 45, prefer group 2 metals such as barium dihydrogen peroxydi ably about 8 to about 25, wt.%. The humectant, prefera phosphate (BaH2P2O8), calcium dihydrogen peroxydi bly propylene glycol and more preferably polyethylene phosphate (CahaP2O8), and the like. glycol (e.g. PEG 400,600), prevents drying out of the The compositions of this invention are formulated to composition and often also functions as a liquid carrier contain or comprise a safe and therapeutically effective or vehicle, alone or in combination with water. amount of the essential PDP, preferably KPDP, i.e. an These compositions may have a pH measured as a amount sufficient to alleviate skin lesions based on a 20% aqueous slurry of about 4.5 to about 10.5, but a reasonable benefit/risk ratio normal in any medical 10 range of about 7.5 to 10.5, especially about 8.5 to 10.5, treatment, unduly low proportions obviously tending to is preferred since the PDP, especially KPDP, appears be insufficiently therapeutic and unduly high propor to be more stable, i.e. with better rentention of active tions obviously tending to introduce skin irritation oxygen activity, at these more alkaline ranges. The pH problems. Typically, these compositions may contain can be controlled by inclusion of the required amounts