Design and Evaluation of Time Dependent Delayed-Release Diclofenac Sodium Tablets for Chronopharmaceutical Drug Delivery

Abstract

This research was aimed a tformulating and evaluating time dependent delayed-release diclofenac tablets for chronopharmaceutical drug delivery using press-coating technology. Rapid disintegrating diclofenac core tablets were initially formulated using the direct compression method. Coats of powdered tragacanth or xanthan gum alone, and in combination in various mixing ratios of 25:75, 40:60, 50:50 and 75:25 were compressed around the core tablet to form 3- layered tablets. The press-coated tablets were evaluated for post compression parameters such as weight variation, crushing strength, friability as well as, swelling index, lag time and in vitro release studies in three different simulated gastro-intestinal fluids. The result revealed that the core and compression coated tablet formulations were within the official specified limits. The release profile of the press coated tablets exhibited lag times depending upon the type, amount and polymer combination ratio in the tablet coat. Optimization was done using analysis of variance (ANOVA). The optimized batch F6 which consisted of 40% xanthan and 60% tragacanth gave a lag time of 6h followed with burst release and complete drug release of 98.51%. This research shows that press-coated diclofenac tablets with 40:60% xanthan and tragacanth gum coat can be exploited in chronopharmaceutical delivery of diclofenac sodium.

Keywords

• chronotherapy
• press-coated tablets
• diclofenac sodium
• rheumatoid arthritis.