246 JOURNAL OF THE SOCIETY OF COSMETIC CHEMISTS The irradiated membranes did not exhibit a signifi- cant increase in the amount of rolmerin permeating relative to the normal skin, nor did the tolmetin applied to irradiated skin have a greatly increased flUX. The highly ionized solutions permeated signifi- cantly less than the solutions with a lesser degree of ionization. The release and in vitro permeability studies of salicylic and benzoic acid from topical formula- tions A. Jain, A. Sakr, Ph.D., and J. L. Lichtin, Ph.D., University of Cincinnati, Cincinnati, OH, and Jonas C. T. Wang and S. Wisniewski, Johnson & Johnson Baby Products Co., Grandview Road, Skillman, NJ 08558 The objectives were to study the release and in vitro permeation profiles of salicyclic and benzoic acid from topical formulations, as a function of film thickness and vehicle. A combination of 0.5 % and 1% w/w off salicyclic and benzoic acid was incorpo- rated in cold cream U.S.P., polyethylene glycol ointment N.F., white petrolatum U.S.P., hydro- philic ointment U.S.P., alcoholic gel, and ethanol. A Spectra Mesh © fluorocarbon filter was used for the release studies, and abdominal sections of hair- less mouse skin and human cadaver skin were used for permeability studies. Finite doses of each for- mulation were applied at three different thick- nesses. The studies were conducted using Franz dif- fusion cells and Sorensen's phosphate buffer, pH 7.40, as the receptor medium. One hundred fifty microliters of receptor fluid was withdrawn with re- placement and analyzed by HPLC. The study re- sults suggested that depending on the thickness of the film applied, the overall delivery mechanism was formulation- and compound-dependent. It was observed that the permeation rate of drug delivery was highly dependent on the magnitude of parti- tioning and solubility. Vehicle influences on de- livery were observed where the solubilized drug fraction was low. SCIENTIFIC SESSION E ADVANCES IN SURFACE SCIENCE II The use of foams in cosmetics Sydney Ross, Department of Chemistry, Rensselaer Polytechnic Institute, Troy, NY 12180-3590 The chief use of forms in cosmetics is to supply a ready-made detergent foam for shaving. The pur- pose of the foam is to soften the hair and to lubri- cate the razor. The foaming agent is a combination of anionic and nonionic surface-active solutes. Shaving foam is stabilized by the presence of a plastic microfilm consisting of a gelled combination of solutes and water. Three-component systems of this chemical type have an L 1 or aqueous liquid crystal phase at certain overall concentrations of the components. The sur- face activity of the solute mixture is responsible for creating a film of different composition from the underlying isotropic solution this film, at appro- priate overall concentrations, has the composition of the L 1 phase, which is thus segregated by the fore- going mechanism, i.e., spontaneous adsorption of solute, in the form of a microlayer at the surface. Neither the L 1 phase nor the aqueous isotropic so- lution, when separate, form stable foams, but they do so when combined. The role of industrial re- search is to determine the appropriate composition for these effects to occur, based on foam stability as the ultimate indicator, in contrast to the academic approach, admittedly more laborious and, for the required application, less direct, in exploring phase-diagram behavior. Multipie-phase emulsions Dr. G. M. Eccleston, University of Strathclyde, Glasgow, U.K. Cosmetic and pharmaceutical emulsions, such as lo- tions and creams, are rarely simple oil-in-water or water-in-oil preparations. They are more likely to be complex colloidal systems containing several surfactants, amphiphiles, and other additives, and to be composed of additional phases (e.g., lameliar liquid crystalline or gel) to oil and water. These additional phases form in aqueous emulsions when the emulsifiers, in excess of those required to stabi- lize oil droplets, interact with continuous-phase water. Thus the phase behavior of the emulsifiers and their mixtures in water can provide valuable information about microstructures of emulsions prepared with them. In this paper, it will be shown how the behavior of many dermatological emulsions during manufacture, storage, and use (i.e., after application to the skin) can be related to their com- ponent phases. Polymer/surfactant interaction E. D. Goddard, Ph.D., Union Carbide Corpora- tion, Specialty Chemicals Division, Tarrytown, NY 10591 Interaction between water-soluble polymers and suffactants, which are common ingredients of cos- metic formulations, is a widespread phenomenon. While attraction is strongest when the two ingre- dients bear an opposite electrical charge, this con- dition is not a prerequisite for interaction. Guide-

ABSTRACTS 247 lines for predicting the type and extent of interac- tion that can occur will be presented together with a description of the effect of structural variation of the two components. The different types of physical forces involved in forming the "complexes" will be outlined, as well as several ways of investigating their formation. The types of property change that can be expected of both components will be dis- cussed these include changes in adsorptive and vis- cosifying characteristics. Lipoproteins, the tradi- tional surfactant/polymer complexes of natural or- igin, will not be included in this reivew, which will be restricted to synthetic polymer/surfactant systems. Stabilization of emulsions by adsorbed macro- molecules Robert Y. Lochhead, Ph.D., BF Goodrich Com- pany, P.O. Box 122, Avon Lake, OH 44012 Stabilization of dispersions and emulsions by ad- sorbed polymers is not new. It has been practiced since the time of the ancient Egyptians and Chi- nese. On the other hand, basic understanding of the fundamental science that underlies this phenomena is relatively new, and this area is currently a focus of much scientific research. This paper will consider the adsorption and confor- mation of macromolecules at solid/liquid and liquid/liquid interfaces the mechanism by which "steric stabilization" operates the benefits of steric stabilization and its limitations how electrosteric stabilization can be used to provide triggered release of actives from a preparation to a substrate and fi- nally, formulation guidelines for the preparation of sterically-stabilized emulsions. SCIENTIFIC SESSION F (Concurrent) COLOR COSMETICS Powder product technology innovation through novel raw materiM selection Alan Farer, Cosmair, Inc., 285 Terminal Avenue, Clark, NJ 07066 In the past, innovation was a word typically used to describe cosmetic treatment items, moisturizers, wrinkle creams, and high-SPF waterproof sun- screens. Today, however, innovation has become essential to the power product development chemist as well. Aesthetically, today's powder products feel dramat- ically different than they did just a few years ago. We have the capability of making anhydrous makeups and blushers feel like powders, and powder makeups and blushers feel like creams. Typical raw materials have become innovative through treatments with silicones, lecithin, amino acids, metallic soap, tri-isostearyl trimerate, and others. Also, novel manufacturing techniques have provided us with the microfine spherical polyeth- ylenes, nylons, silicas, titanium dioxide, speciality iron oxides, and micro=bubbles. Functionally, through proper utilization of these novel raw materials, today's powder development chemist is creating products that not only look good in the display case but have wonderful appli- cation and feel properties while markedly im- proving the user's physical appearance. Through discussion of the varied raw materials, you will come to understand the innovative capabilities of today's powder development chemist. The technology of cosmetic pencils John Cunningham, COSMOLAB Inc., 1100 Gar- rett Road, Lewisburg, TN 37091 Extruded pencils present their own particular set of formulation challenges. Current technology dictates that extruded bases re- quire a high solid/oil ratio to form stable sticks, a requirement that runs counter to the consumer de- sire for the product to have the smooth color lay- down of conventional molded leads. Unfortunately, many of the raw materials that best achieve these attributes tend to form polymorphic crystalline structures. In practice, this can lead to long-term product instability that in turn manifests itself in such ways as lead-hardening and surface- blooming. The importance, therefore, of raw mate- rial selection cannot be overemphasized when em- barking upon such a development project, and the more conventional quality control test methods are best supplemented by additional and more sophisti- cated rheological studies. Visually different cosmetics Ernest Curtis, Kolmar Labs, Inc., King Street, Port Jervis, NY 12771 Color has always been one of the most important marketing tools for cosmetic products. During the past few years visually different products have at- tracted must consumer interest. At first this was done with multicolored items such as two or more shades in a single package. Colors have now been expanded to include multicolor and multishaped products and are being used as a "signal" for actives in core, spiral, or bead forms. Finally, colors can be used to signal the consumer to two distinct products in one or to change color when products are used to show that these products are working.