INVITRO SORPTION OF ALUMINUM COMPLEX TO GUINEA-PIG STRATUM-CORNEUM

[摘要] Sorption of Al complexes to guinea pig stratum corneum was studied using fluorometric and atomic absorption spectrophotometry. Sorption, desorption and binding properties of the 2 Al systems most often used in topically applied antiperspirants, AlCl2 and aluminum chlorohydrate, Al2(OH)5Cl .cntdot. 2H2O were examined as a function of Al concentration, sorption time, state of hydration and for various delipidized tissue specimens. Results indicated rapid uptake of Al species in both systems from aqueous solutions for partially hydrated tissue, reaching 50% saturation levels in .apprx. 30 min. Pseudo-equilibrium sorption isotherms followed a Langmuir-type sorption behavior over the 10-4-5 .times. 10-3 M Al concentration range for both systems reaching plateau sorption capacities. At higher Al concentrations, aluminum chlorohydrate isotherm exhibited a long linear increase in sorption following this initial plateau. Sorption of the various Al species depended on the hydration state of the tissue with increased sorption of 2- to 3-fold over tissue prehydration time periods of 0-96 h. Desorption studies indicated significant reversibility of AlCl2 sorption from partially hydrated tissue but little desorption from fully hydrated tissue. Little desorption was observed with aluminum chlorohydrate regardless of tissue hydration levels. These differences were interpreted in terms of the inherent physical-chemical properties of the species contained in these 2 aqueous Al (III) ion systems.