Abstract

FORMULATION AND EVALUATION OF MATRIX TRANSDERMAL PATCHES OF RIZATRIPTAN FOR TREATMENT OF MIGRAINE

Vivek Parihar*, B. K. Dubey, Deepak Kumar Basedia and Bhushan Kumar Korde

Abstract

The objective of the present work was to formulate transdermal patches of rizatriptan in order to improve the half-life and bioavailability of the drug. The patches were prepared using varying the ratio of the matrix polymers methyl cellulose and Eudragit RL100 as well as the plasticizer polyethylene glycol. The patches were prepared by solvent casting method. The patches were formulated using solvent casting method. The results show that increasing the concentration of Eudragit RL100 and PEG causes an increase in the thickness of the patches. The weight variation was found to be around 1% for all the formulations irrespective of the polymer and plasticizer ratios. The folding endurance was lower for patches with high concentration of methyl cellulose and increased with increasing concentration of Eudragit RL10. The concentration of the plasticizer played an important part in the folding endurance. Higher plasticizer improved the foldability of patch. The moisture content was also found to be affected with the polymer and plasticizer. High Eudragit RL100 and high plasticizer presented higher moisture content. All the patch formulations exhibited drug content of more than 90%. The highest drug concentration was found in formulations containing ethyl cellulose and Eudragit RL100 in equal ratio. The best fitting model (Peppas model) exhibits a non-fickian diffusion or anomalous diffusion for RPA7 which depends on erosion controlled release and diffusion release rate together.

Keywords: Rizatriptan, Transdermal patch, Eudragit, Bioavailability, First pass metabolism.