The single-pass perfused rabbit ear as a model for studying percutaneous absorption of clonazepam. II. Influence of hydrogel-borne propylene glycol and skin pretreatment with lauryl alcohol.

ABSTRACT

Enhancers of the percutaneous diffusion of clonazepam in the isolated single-pass perfused rabbit ear were evaluated and included propylene glycol (PG), polyethylene glycols (PEGs) of different molecular weight, as well as skin pretreatment with lauryl alcohol (LA). PG caused a concentration-dependent increase in the diffusion of clonazepam, due partly to the increased solubility of the active principle in the hydrogel. PEGs of molecular weight up to 3,000 Daltons added to the PG hydrogel showed a simple additive effect on percutaneous diffusion enhancement induced by PG. Transdermal delivery of clonazepam also increased as a function of exposure time following pretreatment with LA.