POLYQUATERNIUM- 10 UPTAKE 235 Table II Effect of Polyquaternium-10 Concentration and Addition of 0.10% HMW HEC on Polyquaternium-10 Uptake by Bleached Hair (Average N = 3) Mildly Harshly bleached hair bleached hair (mg/g) (mg/g) 0.05 % Polyquaternium- 10 control 0.05% Polyquaternium- 10/0.10% HMW HEC 0.20% Polyquaternium- 10 0.20% Polyquaternium- 10/0.10% HMW HEC 2.8 (0.1) a 8.6 (0.2) 2.2 (0.1) 8.0 (0.2) 3.5 (0.2) 9.1 (0.3) 3.7 (0.4) 9.5 (0.3) a Numbers in parentheses indicate standard deviation. HEC, HPMC, and HMHEC are included in a cationic treatment solution. This decrease is most likely a result of limited competitive adsorption of the nonionic cellulosic by the hair surface. Harshly bleached hair shows increased cationic adsorption when HPMC or HMHEC are included in cationic treatment solutions. High-molecular-weight HEC reduced polyquaternium-10 uptake for both hair bleach types when included in 0.05% cationic polymer solutions. There was no difference in cationic adsorption from 0.20% solutions containing HMW HEC for either hair bleach type. REFERENCES (1) A. L. L. Hunting, Shampoo thickeners, Cosmet. Toilerr., 97, 53-63 (1982). (2) A. L. L. Hunting, Encyclopedia of Hair Conditioner Ingredients (Micelle Press, Cranford, NJ, 1983), p. 250. (3) M. T. Clarke, Water-soluble cellulose ethers for hair care products, $eifen Ole Fette Wasche, 17, 684-687 (1990). (4) E. D. Goddard and W. C. Harris, An ESCA study of conditioning polymers on hair substrates,J, Soc. Cosmet. Chem., 38, 233-246 (1987). (5) E. D. Goddard, J. A. Faucher, R.J. Scott, and M. E. Turney, Adsorption of Polymer JR on keratinous surfaces--Part II,J. Soc, Cosmet. Chem., 26, 539-550 (1975). (6) Y. K. Kamath, C. J. Dansizer, and H.-D. Weigmann, Surface wettability of human hair. II. Effect of temperature on the deposition of polymers and surfactants, J. Appl. Polym. Sci., 30, 925-936 (1985). J. A. Faucher and E. D. Goddard, Influence of surfactants on the sorption of a cationic polymer by keratinous substrates, J. Colloid Interface Sci., 55, 313-319 (1976). J. A. Faucher, E. D. Goddard, and R. B. Hannan, Sorption and desorption of a cationic polymer by human hair: Effects of salt solutions, Text. Res. J., 47, 616-620 (1977). P. Finkelstein and K. Laden, The mechanism of conditioning with alkyl quaternary ammonium compounds,J. Appl. Polym. Symp., 18, 673-680 (1971). J. M. Hutter, M. T. Clarke, E. K. Just, J. L. Lichtin, and A. Sakr, Colloid titration: A method to quantify the adsorption of cationic polymer by bleached hair,J. Soc. Cosmet. Chem., 42, 87-96 (1991). E. D. Goddard, Substantivity through cationic substitution, Cosmet. Toiletr., 102, 71-80 (1987). Aqualon Company, Product Data Sheet #4032, Wilmington, DE, 1988. Aqualon Company, Product Data Sheet #56.001-USA, Wilmington, DE, 1990. (7) (8) (9) (10) (11) (12) (13)

j. Soc. Cosmet. Chem., 43, 237-249 (September/October 1992) Development of a model of the lipid constituent phase of the stratum corneum: II. Preparation of artificial membranes from synthetic lipids and assessment of permeability properties using in vitro diffusion experiments D. KITTAYANOND, S. M. DOWTON, C. RAMACHANDRAN, G. L. FLYNN, and N. WEINER, College of Pharmacy, The University of Michigan, Ann Arbor, MI 48109-1065. Received April 28, 1992. Synopsis This paper describes the development of model membranes from liposomes using commercially available synthetic lipids. The composition of the lipid mixture used to prepare the liposomes was based on earlier studies to optimize the strength of interlipid interactions within the bilayers. Model membranes were prepared by extruding liposomes through a membrane filter below the phase transition temperature of the lipid mixture. The resulting membrane filter, with the deposited lipids, was then dried and treated with calcium chloride to allow transformation of the liposomal bilayers into extended sheet structures. The treated membranes were dried and mounted on diffusion cells. A variety of markers was then used to test the permeability characteristics of the model membrane. The results suggest that the membrane prepared using synthetic lipids is a suitable model for permeation characteristics of skin. INTRODUCTION In a previous paper (1), the optimization of the composition of liposomes prepared using commercially available semi-synthetic lipids suggested that the interlipid interactions of this mixture were similar to that obtained using lipids extracted from porcine stratum corneum. It was therefore of interest to determine if model membranes of the stratum corneum lipid compartment can be developed by the use of the optimized synthetic lipid mixture. The preparation of model membranes with synthetic or semi-synthetic lipids would also obviate excessive reliance on animal skin studies if they are shown to possess permeability characteristics similar to skin. The quest to circumvent problems associated with the use of human or animal skin to answer basic questions has prompted an extensive search for a reliable in vitro model. Attempts to adapt synthetic polymeric membranes such as cellulose acetate membranes 237