Influence of cellulose polymers type on in vitro controlled release tablets containing theophylline

Abstract

In this study, the effect of ethylcellulose (EC) and 6 types of hydroxypropylmethylcellulose (Methocel® K100M, K100MPRCR, K15MPRCR, K4MPRCR, K4M PR and E4MCR) on release profile of theophylline from matrix tablets was evaluated. Formulations tablets were prepared by either wet granulation or direct compression technique. The tablets were evaluated for physical characteristics and in vitro release of drug was performed as described in USP 30 ed. (Test 3). All formulations with cellulose polymer produced tablets easily and with physicals characteristics in accordance with official limits. Drug dissolution tests showed that formulations with 15% of Methocel® K4MPR, 15% of Methocel® K4MPRCR and 30% of Ethocel® N10STD, obtained by direct compression method, complied with official specifications, in terms of release profile and diffusion was the main mechanism involved in theophylline delivery.