FORMULATION AND INVESTIGATION OF NICARDIPINE HCL-ALGINATE GEL BEADS WITH FACTORIAL DESIGN-BASED STUDIES

The release rate of nicardipine HCl from various alginate gel bead for mulations was investigated. The formulations were prepared by utilizin g 2(3) factorial design. The effect of drug:polymer weight ratio, CaCl 2, and sodium-alginate concentration on the time for 50% of the drug t o be released (t(50%)) and the drug entrapment efficiency were evaluat ed with analysis of variance. The mean particle size and the swelling ratio of the beads were determined. The in vitro release studies were carried out by flow-through cell apparatus in different media (pH 1.2, 2.5, 4.5, 7 and 7.5 buffer solutions). Drug:polymer weight ratio and the interaction of drug:polymer weight ratio and CaCl2, concentration had a significant effect on the drug entrapment efficiency. The releas e of nicardipine was extended with the alginate gel beads, which were prepared in a ratio of 1:1 (drug:polymer). The release of drug from al ginate gel beads took place both by diffusion through the swollen matr ix and relaxation of the polymer at pH 1.2-4.5. However, the release w as due to the diffusion and erosion mechanism at pH 7-7.5. (C) 1998 El sevier Science BN.