Formulation and Evaluation of Floating Tablets of Diltiazem Employing Hydroxy Propyl Methyl Cellulose and Carbopol

Abstract

The objective of the present study is to evaluate HPMC K100, HPMC K4M and carbopol P930 as matrix formers in this design of floating tablets of diltiazem hydrochloride, a highly water soluble drug. Floating tablets of diltiazem (90 mg) were formulated employing (i) hydroxy propyl methyl cellulose (HPMC) K100 (ii) HPMC K4M and (iii) Carbopol P930 as matrix formers at 30 and 50 % strength, sodium bicarbonate at 7.5, 10 & 12.5 % strength as gas generating agent and bees wax (10 %) as floating enhancer and the tablets were evaluated for floating and drug releases characteristics. Diltiazem floating tablets formulated employing hydroxy propyl methyl cellulose K100 and HPMC K4M as matrix formers at 50 % strength and containing sodium bicarbonate (12.5 %) as gas generating agent exhibited floating over 35 to 48 h with a floating lag time of less than 1 min. These floating tablets also gave slow and controlled release of diltiazem over 24 h and were found suitable for once a day administration (24 h). HPMC K100 and HPMC K4M were better suitable as matrix formers than carbopol P930 for floating tablets of diltiazem, a highly water soluble drug.