Effects of polyoxypropylene 15 stearyl ether and propylene glycol on percutaneous penetration rate of diflorasone diacetate.

Theoretical models for percutaneous penetration are described, and a diffusion apparatus useful in the evaluation of transport kinetics of drugs applied to skin is discussed. Experimental data are presented for: (a) the flux of diflorasone diacetate through hairless mouse skin, (b) the percutaneous penetration profile of propylene glycol, (c) the effects of vehicle concentrations of polyoxypropylene 15 stearyl ether and propylene glycol on the percutaneous flux of diflorasone diacetate, (d) skin--vehicle partition coefficients of diflorasone diacetate, (e) the solubility profile of diflorasone diacetate as a function of solvent concentration, and (f) the alteration of the skin's resistance to the penetration of diflorasone diacetate due to propylene glycol. Excess solvent in a vehicle caused a decrease in the percutaneous flux of diflorasone diacetate. Formulations containing 0.05 and 0.1% diflorasone diacetate had similar penetration rates when the solvent concentration was optimized for each percentage of diflorasone diacetate.