46 JOURNAL OF THE SOCIETY OF COSMETIC CHEMISTS produces high resolution images of the ultrasonic wave pattern. The resulting image reveals elastic properties in the sample. Because of the unique interaction between ultrasound and the sample, the acoustic image reveals elastic property variations within the sample. The technique has been used in the life and material sciences and is currently being exploited for industrial quality control and flaw detection in optically opaque materials. Shea butter--A new and exceptional cosmetic raw material Victoria I. Onwuchekwa, John Ward, Ph.D., Lloyd Kennon, Ph.D. and Anthony Cutie, Ph.D., Arnold and Marie Schwartz College of Pharmacy, Long Island University, 75 DeKalb Ave., Brooklyn, NY 11201. Shea Butter was compared for efficacy and perfor- mance with Cocoa Butter. The raw materials were screened for humectant properties by subjecting them to varying relative humidities in a dessicator. Shea Butter showed a higher capability of water uptake at high relative humidities. Physical analysis showed that Shea Butter had two polymorphic forms and a transition temperature of 35.5øC. Cocoa Butter has four polymorphic forms and several transition temperatures. W/O and O/W emulsions of the two materials were evaluated. Accelerated stability studies at 4øC, 20øC, 37øC, 50øC for eight weeks showed that both emulsions were stable but have a tendency to degrade at higher temperatures (50øC). Degradation is marked in Cocoa Butter lotions. Shea Butter showed remarkable stability in W/O emulsion, especially at 10% level. Cocoa Butter could not hold together in W/O emulsion for any period of time. Overall, Shea Butter showed better results as an humectant and emollient. It is stable at extreme temperatures and shows good stability in W/O emulsions. Microemulsions: Evolving technology for cos- metic applications Dinesh O. Shah, Ph.D., University of Florida, Gainesville, FL 32611. Microemulsions, which are optically transparent oil-water dispersions, were spontaneously pro- duced upon mixing hexadecane, hexanol, potas- sium oleate, and water in specific proportions. The viscosity of the microemulsions was measured for several water/oil ratios including the phase-inver- sions region. The striking optical and viscosity changes observed at specific water/oil ratios were in agreement with the proposed mechanism of phase-inversions, namely, water spheres --• water cylinders --• water lammellae --• continuous water phase, for this system. In the phase-inverfion region, the dispersion exhibited birefringence and rehopectic properties. An extremely high viscosity (100,000 cps) exhibited by the dispersions between water/oil ratios of 2.0 and 3.5 were explained in terms of ion-dipole association between oleate and hexanol molecules on adjacent droplets. The application of these principals in cosmetic formulations are discussed. Alternative methods for the formulation of anhydrous lipid systems for topical use David C. Steinberg, Gianni Proserpio, Ph.D. and Stefano Dorato, Ph.D., Tri-K Industries, 99 Kindermack Rd., Westwood, NJ 07675. Anhydrous, oil-based ointments represent a tradi- tional pharmaceutical product for topical use. Most current products consist of old formulations based on petrolatum, mineral oil, lanolin and mineral waxes. The aim of this study is to show, through a series of formulations, alternative tech- niques and raw materials (propoxylated pentaery- thritol ethers, polyisoprenes, and new liquid glyc- erol esters of long chain saturated fatty acids) to prepare anhydrous ointments. These formulations are compounded for their consistency, increased or decreased tack, gelling ability, stability, softness and spreadability. Quality control of the viscosity, melting range and texture will also be discussed. Development and clinical testing of contem- porary eye cosmetics Walter H. Stern, M.D., Roger L. Williams, M.D., Monroe Lanzet and Stephen R. Schwartz, Univer- sity of California School of Medicine, Department of Ophthalmology, U-490, San Francisco, CA 94143. This paper deals with the issues of rapidly changing consumer expectations and their effect on the formulation, safety and relevancy of clinical testing of eye cosmetics. The authors discuss earlier formulations, modes of application, microbiology and the eye safety issues associated with eye cosmetics. The demand for more functional, longer wearing products with greater assurance of safety, had led us to propose a clinically relevant method for assessing the safety of eye cosmetics. The technique employed relies on multiple applica- tions of test and control products to the eyes three times a day. Ophthalmologic evaluation of the periorbital skin and the anterior segment of the eye was performed by both penlight and slit lamp microscopy. These examinations were carried out by Board certified ophthalmologists over a three week period of continued product use. Areas for future exploration include panel size and subject composition, changes in methodology, assessment

ABSTRACTS 47 of the predictive accuracy of these relatively small panels to wide scale consumer usage. Effect of polyols on stability of suspensions containing nonionic wetting agents Joel L. Zatz, Ph.D. and Ru-Yun Lue, Rutgers University College of Pharmacy, P.O. Box 789, Piscataway, NJ 08854. In an earlier study, it was shown that propylene glycol caused flocculation in sulfamerazine suspen- sions containing a nonionic surfactant as wetting agent. The present investigation was intended as a more in-depth inquiry into the influence of polyols on suspension stability. Polysorbate 80 and poly- sorbate 20 were employed as wetting agents for sulfamerazine, salicylamide and butamben suspen- sions. After preliminary investigation using several polyols, sorbitol was selected for detailed study because of its negligible effect on solubility of the suspended drugs. In the absence of sorbitol, all of the suspensions were deflocculated and they settled to a non-redispersible cake. The addition of sorbitol resulted in an increase in sedimentation volume and prevented cake formation. The concentration of sorbitol needed depended on the solid and on the surfactant. Sorbitol effectiveness in preventing caking was enhanced by a rise in temperature or by the addition of a salt, but reduced by an increase in surfactant concentration. Cloud point and surface tension studies implicated a reduction in polyoxyethylene hydration by sorbi- tol as a key factor in counteracting deflocculation of the suspensions. Cloud points correlated extremely well with sulfamerazine suspension data. They indicate the trends observed with other suspensions. Physical stability assessment of emulsions and related disperse systems George Zografi, Ph.D., University of Wisconsin School of Pharmacy, Madison, WI 53706. Most measurements of disperse system physical stability fall into two categories: 1) application of stress conditions which accelerate instability, followed by attempts to predict long-term stability and 2) use of techniques which are very sensitive to the small changes which might occur during short periods after preparation of the disperse system. Both approaches may be faulty. The first may eliminate good products because of excessively applied artificial stresses, and the second may only indicate very bad systems because of inadequate sensitivity. Before one can develop techniques to properly assess the short and long term physical changes which might take place, it is important to know as much as possible about the physical chemical nature of the processes bringing about change. Phase separation due to coalescence, for example, reflects phenomena quite different from those due to creaming in an emulsion. How a thermal or theological stress used in any test can alter the patterns of physical change is a critical factor in determining its usefulness. This paper discusses a variety of approaches which may be used to understand the causes of disperse system instability and the meaning of the tests we use.