J. soc. cos. CHEM. 15, 327-335 (1964) COSMETIC APPLICATIONS OF POLYVINYL ALCOHOL By B. W^v.r, Pi.D., and GLEN J. SPERANDIO, Presented September 24-25, 1963, Seminar, Boston, Ma•. ABSTRACT The use of polyvinyl alcohol in the formulation of safe, improved cosmetic preparations is described. Polyvinyl alcohol has been ac- cepted by the Food and Drug Administration as a component of topi- cally applied products and is a raw material with unrealized potential for use in cosmetics. The formulation of suntan lotions, cream hair dressings and liquid make-ups containing polyvinyl alcohol is de- scribed. Polyvinyl alcohol acts as a protective colloid in emulsification and has unusual film-forming properties. A method for determining film-forming properties and film strength of cosmetic products con- taining polyvinyl alcohol is described. INTRODUCTION As the science of cosmetic formulation has become more so- phisticated and exacting, the need for adjuvants which are both functional and safe for human use has been increasing proportionately and the search for better cosmetic materials is well under way. Polyvinyl alcohol (PYA) is a compound that holds much promise for use in cosmetics, yet its potential has not been fully realized by the majority of those who are most intimately concerned. As early as 1937 it was used as a component of shaving creams (1), and in 1945 Lesser reported on its potential applications in other types of cosmetics (2). In addition, other authorities, such as deNavarre and Sagatin, have shown an interest in the product (3, 4). In checking the literature it is interesting to note that in very few instances are complete specifications for the types of polyvinyl alcohol used in a particular formulation given. This is unfortunate because the compound is commercially available in over a ' * Purdue University School of Pharmacy and Pharmacal Sciences Research Laboratories, Lafayette, Ind. 327

328 JOURNAL OF THE SOCIETY OF COSMETIC CHEMISTS dozen different types, each with different formulation characteristics and no two are exactly the same. CHEMICAL AND PHYSICAL BACKGROUND Polyvinyl alcohol is a polyhydric alcohol with secondary hydroxyl groups on alternate carbon atoms. It is prepared by polymerizing vinyl acetate with heat in the presence of a catalyst to form polyvinyl acetate. This is then hydrolyzed to produce polyvinyl alcohol. To effect control of product characteristics both the molecular weight and the degree of alcoholysis or hydrolysis are controlled. Molecular weight is a measure of the degree of polymerization and is reflected in viscosity of the com- pound's aqueous solutions. Three general ranges of molecular weights are commercially available. High viscosity PVA has an average molecular weight of about 200,000, medium viscosity material averages about 130,- 000 and low viscosity PVA has a molecular weight of about 30,000. As the molecular weight increases, higher values are obtained for the tensile strength, tear resistance, elongation and flexibility of simple PVA films (S). Products with different degrees of hydrolysis are also offered, ranging from material which is about 75% hydrolyzed on up to a material which is practically 100% hydrolyzed. The completely hydrolyzed material is pure polyvinyl alcohol, while the 75% hydrolyzed material contains an appreciable amount of polyvinyl acetate which has not been converted to the alcohol. Changes in the degree of hydrolysis radically alter the characteristics of the material. As the degree of hydrolysis increases, tensile strength, tear resistance and elongation of simple PVA films in- crease. Typically, water solubility increases with an increase in degree of hydrolysis up to a level of 88% hydrolysis. When the degree of hydrolysis is increased beyond 88% there is a reduction in water solubility, probably as a result of hydrogen bonding (5). The two main polyvinyl alcohols suitable for cosmetic study are the Elvanols, © made by the DuPont Company (6), and the Gelvatols, © sup- plied by the Shawinigan Resins Company (7). Eight different Elvanols and eleven different types of Gelvatols, with additional fine variations within a given type, are currently offered to the market. One can easily see the confusion that can arise when an author simply states that he has successfully used polyvinyl alcohol but does not specify the degree of hydrolysis, molecular weight, type or viscosity of the PVA employed. This discussion will be limited to those types of polyvinyl alcohol outlined * From the research laboratories of Purdue University School of Pharmacy and Pharmacal Sciences, I.afayette, Ind.