The effect of penetration enhancers on the kinetics of percutaneous absorption.
J Control Release 1987 Jun; 5(1):43-51
A model for the effect of penetration enhancers on the kinetics of percutaneous absorption and transdermal drug delivery was described. Zero order and first order kinetic components for transdermal absorption profiles were considered, and simulated data was compared to known plasma concentration time profiles for several representative drugs. Two absorption enhancers were profiled, including one that induced a ten fold increase in the diffusion coefficient of drugs crossing the stratum corneum (PE1) and a second that reduced the stratum corneum viable epidermal tissue partition coefficient to 10 percent of the value observed in the absence of the enhancer (PE2). The delivery systems modelled included a 10 square centimeter device that released the drug at a constant rate and an incidental device that included a priming dose released with first order kinetics. PE1 acted as predicted for relatively hydrophilic drugs, but deviated from the model at oil to water distribution ratios greater than two. PE2 was comparable to PE1 in enhancing drug delivery for hydrophilic agents, and significantly improved the transdermal delivery of lipophilic agents. The results were discussed in relation to the physicochemical characteristics of the drugs and the absorption enhancers.
NIOSH-Publication; NIOSH-Grant; Dermatitis; Skin-absorption; Chemical-kinetics; Pharmacodynamics; Analytical-models; Biological-transport; Drug-therapy
Pharmacy University of California 926 Medical Sciences Building San Francisco, Calif 94143
Journal of Controlled Release
University of California San Francisco, San Francisco, California