Design and Evaluation of Diltiazem Mucoadhesive Tablets for oral controlled Release.” Saudi pharmaceutical Journal,11(4

An investigation of the ethanolic extract of the pods of Albizzia lebbeck (L.) Benth. afforded a Mucoadhesive tablets of diltiazem were formulated as matrix tablets employing sodium carboxymethylcellulose (Sodium CMC), hydroxypropylmethylcellulose (HPMC) and ethyl cellulose and were investigated. Tablets formulated employing sodium CMC and HPMC alone were slowly eroded and were dissolved completely within 4-5 hr. When ethyl cellulose was incorporated, the tablets remained intact and provided slow release of diltiazem for over 10-12 hr. Tablets formulated employing sodium CMC with 5 % ethyl cellulose gave slow and complete release over a period of 12 hours and were found suitable for the maintenance portion of oral controlled release tablets. These tablets exhibited good mucoadhesion in the intestine for 10-12 hr in the x-ray studies. Non-Fickian release was observed from most of the formulations. A two-layered tablet formulation, an immediately releasing layer consisting of diltiazem and croscarmellose sodium, (a superdisintegrant) and a matrix consisting of diltiazem, sodium CMC and ethyl cellulose as a second maintenance layer, gave release close to the theoretical sustained release (SR) needed for diltiazem. Key Words: Mucoadhesive tablets, diltiazem, ethyl cellulose, controlled release (CR), mucoadhesive polymers