PREFORMULATION STUDIES OF DILTIAZEM HYDROCHLORIDE FROM TABLETED MICROSPHERES

Abstract

Microspheres are solid, spherical particles of protein or polymer-based matrix which comprised of a fairly homogeneous mixture of polymer and active agents.It undergoes considerable presystemic metabolism (45-55%) which results in reduced bioavailability. Diltiazem hydrochloride was scanned in the Methanol, acid buffer, pH 1.2and phosphate buffer, pH 7.2. 10 mg of drug was dissolved in methanol in 100 ml in volumetric flask, and volume was made to 100 ml with same solvent. This stock solution was further diluted to get concentration of 10mcg/ml. This solution was scanned in UV-spectrophotometer and characteristic peak was observed at 239 nm for methanol,237 nm for acid buffer, pH 1.2 and phosphate buffer, pH 7.2. Standard curve of Diltiazem hydrochloride was plotted in Methanol, acid buffer (pH 1.2) and phosphate buffer (pH 7.2). The critical values for regression coefficient in each plot was less than 0.001 (i.e., P < 0.001). That indicates that there was high linear correlation between concentrations of drug with absorbance. Keywords: Diltiazem hydrochloride, regression coefficient, bioavailability, Microspheres.