Formulation and evaluation of a transdermal drug delivery system for nicardipine hydrochloride: in vitro and in vivo studies

In the present investigation, nicardipine HCl was formulated in different traditional transdermal formulations that are used topically on the skin for systemic action. These formulations were an ointment, an o/w emulsion, a gel, an emulgel and a cellulose acetate butyrate film. Enhancers; namely, dimethyl sulfoxide [DMSO], Tween 80, urea, cetrimide and sodium lauryl sulfate [SLS], were added in different concentrations to the selected pharmaceutical formulations. In vitro studies were carried out on an isolated abdominal rabbit skin using diffusion cell. The correlation coefficient [r], the steady-state flux [J] and permeability coefficient [kp] were calculated. The results revealed that the permeation of the drug trough the skin was mainly dependent on the composition of each base and the type of the added enhancer and its concentration