Development and Evaluation of Indomethacin Controlled Release Press Coated Tablets

Abstract

In the present work, several batches of indomethacin press coated tablets were prepared with drug and
Avicel PH 102 utilizing the press coating technology. The core tablet was compression coated with minimal
compression pressure. The compression coating mixture was formulated using various amount of lactose and xanthan
gum which was used as the release retarding agent. Three formulations (IX-1, IX-2 and IX-3) were designed to
evaluate the release profile as function of xanthan gum load. In vitro drug release testing demonstrated that the drug
release was inversely proportional to the amount of xanthan gum in the coating formulations. In addition,
formulation IX-2 was modified by incorporating hydroxypropyl methyl cellulose (HPMC) 15 cps into the
compression coating formulation to understand their effects on drug release. The formulation was evaluated for its
properties and correlated with in vitro and kinetic release studies. Incorporation of HPMC caused the highest fraction
of drug to be released in the dissolution fluid. The physico-chemical properties of the excipients can be held
responsible for the discrepancy in release rate of indomethacin. From kinetic analysis drug release was found to
follow Higuchi mechanism for all the formulations. Overall, the study concluded that excipients present in the
coating formulations make a significant impact on drug release.