PURPOSE: The aim of this study was to enhance the transdermal absorption of the highly active progestin gestodene from matrix type transdermal delivery systems (TDDS) by formation of prodrugs with improved matrix solubility. METHODS: Gestodene esters were synthesized via acylation of the drug with the respective carboxylic anhydrides. Subsequently TDDS were produced using the solvent cast method. Selected formulations were examined with in vitro diffusion experiments using skin of nude mice. RESULTS: One prodrug, gestodene caproate proved to be an oil at ambient temperature and showed a very high solubilty of over 10.5% in the TDDS matrix. Within in vitro penetration studies using those systems the prodrug exhibited a significantly higher transdermal penetration rate than gestodene from reference systems. Furthermore, the prodrug was hydrolyzed to the parent drug to a high extent during the passage of the skin. CONCLUSIONS: Designing prodrugs to the requirements of matrix TDDS is an efficient way of enhancing the transdermal drug flux rate.
PURPOSE: The aim of this study was to enhance the transdermal absorption of the highly active progestin gestodene from matrix type transdermal delivery systems (TDDS) by formation of prodrugs with improved matrix solubility. METHODS:Gestodene esters were synthesized via acylation of the drug with the respective carboxylic anhydrides. Subsequently TDDS were produced using the solvent cast method. Selected formulations were examined with in vitro diffusion experiments using skin of nude mice. RESULTS: One prodrug, gestodene caproate proved to be an oil at ambient temperature and showed a very high solubilty of over 10.5% in the TDDS matrix. Within in vitro penetration studies using those systems the prodrug exhibited a significantly higher transdermal penetration rate than gestodene from reference systems. Furthermore, the prodrug was hydrolyzed to the parent drug to a high extent during the passage of the skin. CONCLUSIONS: Designing prodrugs to the requirements of matrix TDDS is an efficient way of enhancing the transdermal drug flux rate.