BIODEGRADABLE SOLID LIPID MICROPARTICLES LOADED WITH DILTIAZEM HYDROCHLORIDE FOR ORAL DELIVERY: PREPARATION AND IN-VITRO/IN-VIVO EVALUATION

Abstract

Diltiazem, a benzodiazepine, voltage sensitive ca²⁺ channel blocker with a high therapeutic potential but with a very short biological half life was encapsulated within microparticles. The encapsulation efficiency of prepared SLM reached 70.48±1.67% w/w. Further, the particle size (99.52±1.06μm), surface morphology (spherical) and drug loading efficiency (17.62±2.14%w/w) were investigated. Various formulation and process parameters like drug polymer ratio (3:1), nature and concentration of emulsion stabilizer in the external aqueous i.e. aqueous PVA solution (0.1%), phase viscosity of external aqueous phase (0.5%), volume of external aqueous phase and stirring rate (1000 rpm for 2 h) were optimized. The in-vitro release of diltiazem from the microparticles as observed with the initial burst release of 17% followed by the slow release to avoid dose dumping. The analytical methodology employed for characterization included UV and IR Spectroscopy, DSC, physicochemical stability studies which proves that the prepared solid lipid microparticles appear to have promising abilities for oral administration of diltiazem hydrochloride with improved half life, improved bioavailability and minimized local and systemic GI disturbances.