Sustained Release of Captopril Tablet with Floating System Using a Cross-Linked Matrix of Alginate

Abstract

Captopril has a short biological half-life 2-3 hours and has been used for long-term treatment of hypertension. The properties of captopril such as absorbed well in the stomach, freely water-soluble, instability in intestinal environment, and bioavailability about 65%. This study aimed to determine the physical characteristics and drug release profile of captopril tablet sustained release with a floating system using a cross-linked matrix of alginate with calcium chloride as a crosslinker. Matrix system was obtained by forming alginate cross-linked with a calcium chloride. HPMC K4M was used to help cross-linking reaction. Tablet was prepared by wet granulation with varying levels of sodium alginate and calcium chloride. Dissolution test is carried out by paddle method in HCl pH 1,2; 100 rpm; and 37±0,5oC for 8 hours. Amount of captopril released determined by measuring the captopril dissolved using UV spectrophotometry at λ 205 nm. The result showed that this tablet having physical characteristics suitable with the general requirements for tablets. Drug release profile of captopril tablet sustained release with a floating system using a cross-linked matrix of alginate with calcium chloride as a crosslinker capable keeping release of captopril up to 8 hours (third formula) about 51,226% (DE) and followed zero order kinetics.