RESUMEN
The matrix type transdermal drug delivery systems (patches) of Nitrendipine were prepared by film casting technique. The patches were characterized for physical, in vitro release studies and ex-vivo permeation studies (human cadaver skin). On the basis of in vitro drug release and skin permeation performance, formulation B3 was found to be better than the other formulations and it was selected as the optimized formulation. The final optimized formulation (B3) was subjected to skin irritation, pharmacokinetic, pharmacodynamic and stability studies. The maximum percentage drug release in 48 hours was 94.67 +/- 3.25 for B3 and 91.43 +/- 2.106 for A2 formulation. Again formulation B3 (0.0627 mg/cm2/h) and A2 (0.0566 mg/cm2/h) showed maximum skin flux in the respective series. Patches prepared with Plasdone S-630 were more flexible as compared to PVP K 30 containing patches. Patches prepared with PVP K 30 showed drug release and skin permeation at higher percentage as compared to those containing Plasdone S-630. The interaction studies carried out by comparing the results of ultraviolet, infrared, TLC and DSC analyses for the pure drug, medicated and placebo formulations indicated no chemical interaction between the drug and excipients. The TDDS was found to be free of any skin irritation as suggested by skin irritation score of 1.16 (< 2.00) under Draize score test.