Evaluation of transdermal permeability of pentoxifylline gel: in vitro skin permeation and in vivo microdialysis using Wistar rats.

The aim of the present work was to evaluate the transdermal permeability of pentoxifylline gel in vitro and in vivo. Gel was prepared with carbomer 934 as the base, and the Wistar rat was chosen as an animal model. The effects of percutaneous enhancers on the transdermal permeability of pentoxifylline gel were investigated by in vitro permeation experiments. Cumulative permeation at different times was determined by HPLC. 3% Azone and 5% propylene glycol were used as collaborative enhancers in an optimal formulation. Topical concentrations at different times were measured by microdialysis in vivo. The transdermal process of pentoxifylline fits to a zero-order kinetic equation, and its release profile remains of the zero-order despite the addition of enhancers. In addition, a good in-vitro-in-vivo correlation was achieved.