FORMULATION DEVELOPMENT AND EVALUATION OF DILTIAZEM HYDROCHLORIDE SUSTAINED RELEASE MATRIX TABLET.

The aim of the current study was to design sustained release tablet of Diltiazem hydrochloride and to optimize the drug release profile and dissolution time using response surface methodology. Diltiazem hydrochloride is an antihypertensive drug, a benzothiazepine derivative with vasodilating action. It is prescribed for the treatment of hypertension and other cardiovascular disorder. Antihypertensive should continue for several months. Diltiazem hydrochloride has half-life of 3-4.5 hours. So its chronic use necessitates the sustained release formulation to reduce dose and dosing frequency. A 32 full factorial design (2 factors at 3 levels each) was employed to systematically optimize the drug release profile. Kollidon SR and HPMC K100 were taken as the independent variables. The % drug release at 4 hr and % drug release at 24 hr were dependent variables .Tablets were prepared by direct compression and evaluated for Hardness, Friability, Percent drug content and In-vitro drug release pattern. Both the polymers had significant effect on the drug release and of the tablets. All the formulation release the drug for more than 24 hours. The optimized formulation F6 having Kollidon SR 135mg and HPMC K100 105mg showed maximum release of 98.70 % drug release for 24 hr. Most of the formulation followed Higuchi Model.so sustained release tablet of diltiazem HCl was formed which provide drug release for 24 Hrs.