120 JOURNAL OF THE SOCIETY OF COSMETIC CHEMISTS either polyvinyl alcohol with acrylic polymer or of polyvinyl acetate with acrylic polymer gave concentrates with most of the desirable char- acteristics. Examples of these formulations are given in Table II. In general, the preparation of these formulations was best accomplished by first warming the aqueous solvent system to 60øC and adding the polyvinyl alcohol powder slowly with gentle stirring. The solution was TABLE III Formulation and Evaluation of Spray-on Bandages" Aerosol No. 10-1 13-2 14-3 15-4 16-5 Concentrate formula No. 74-1 74-1 81-4 81-4 81-4 (% by wt.) 38.5% 38.5% 54% 43.8% 41.8% Ethyl alcohol (% by wt.) 31.1% 31.1% 36% 26% 28% Pluronic L-61 ... 10 drops ... 10 drops 10 drops Chloroform (% by wt.) 1.4% 1.4% ......... Octyl alcohol 10 drops ............ Propellants 12/114 20:80 20:80 57:43 20:80 20:80 (% by,wt.) 30% 30% 10% 30% 30% Spray character Quick- Quick- Stream Unstable Quick- breaking breaking foam breaking foam foam foam Film drying time 10 min. 10 min. 10 min. 15 min. 10 min. Stability Good Good Poor Good Poor "The development of aerosols in this study involved the use of plastic-coated glass con- tainers of 80 ml. capacity with Precision standard valves with a foam head. Aerosols were pressure-filled. cooled, and the plasticizer was added. The mixture was then added in small portions with thorough mixing to the Rhoplex emulsion system. The defoaming agents in the aerosol product, to be described later, were added last. Formulation and Evaluation of Aerosols Since all satisfactory concentrates were o/w emulsions, the expected aerosol was destined to be a foam spray, preferably a quick-breaking foam spray. Thus, modifications of the basic concentrate formulation were necessary with the addition of foam breaking agents. Aqueous alcohol aerosol foams have been extensively studied in recent years (5). For a spray bandage it was not desirable to have a high concentration of alcohol as it would enhance penetration of the material through the skin and would irritate mucous membranes or abraded skirt. Other agents used to increase foam breaking were chloro-

AQUEOUS TOPICAL ADHESIVES 121 form, octyl alcohol, and nonionic surface active agents, such as the Pluronics ©.* Examples of formulations of spray-on bandages and their evaluation are given in Table III. One of the serious drawbacks of a quick-breaking foam spray was the excessive amount of material present on application. Too much spray delayed the drying time of the bandage, for the outer layer of spray dried fast, and the film formed delayed further drying beneath it. Too much spray also caused a problem in holding the concentrate to the desired sprayed area after the foam broke. This necessitated experi- mentation with various propellants and valves. Some of the packaging changes which were investigated included the use of a dip-tube of narrow inside diameter, a modified foam head on the valve, and a mechanical breakup valve. None of these changes from a Precision standard valve t provided the desired spray pattern. These changes in the aerosol pack- age are still under investigation. Animal Testing of Spray-on Bandage A limited number of rabbit skin tests on normal and abraded skin of aerosol No. 13-2 were carried out. The spray-on bandage did not show any irritation or toxic reaction. There was no significant difference in healing time of abraded skin with or without the bandage. It was also noted that neutral or acidic drugs such as phenylmercuric nitrate, al- lantoin, or bacitracin were compatible with the bandage formulation. SUMMARY The development of a spray-on bandage with water-soluble resins has been attempted. The main drawback of such a product was the relatively long drying time of the film under the conditions of spray control employed. The best aerosols developed in this study are de- scribed in Table III. Formulations containing a mixture of polyvinyl alcohol and either polyvinyl acetate or acrylic resins were found to pro- duce the best film-forming concentrate. (Received August 20, 1965) * Pluronic, a product of Wyandotte Chemicals Corporation, Wyandotte, Mich. t Precision Valve Corporation, Yonkers, N.Y.