Formulation and Evaluation of Glimepiride Oral Capsules

Abstract

Glimepiride (GMP) is poorly water soluble drug, so solubility is the main constraint for its oral bioavailability. The aim of this study was to investigate the potential of cubosomes as lipid nanocarrier to improve the solubility and sustained action of Glimepiride. Glimepiride is one of the third generation sulfonylureas used for treatment of type 2 diabetes. The rationale of this study was to improve the solubility, dissolution rate and sustained release of the drug. Glimepiride cubosomes were prepared by Top down approach 3 employing GMO as lipid phase vehicle, Poloxamer 407 as stabilizer and distilled water as aqueous phase. The resultant cubosome dispersion were characterized by encapsulation efficiency, in-vitro drug release, particle size, zeta potential, FTIR and SEM. Optimized formulation (F5) showed a maximum drug release of 71 % in 6 hours, particle size of 88.7nm and zeta potential of 43.6 mV. Glimepiride cubosomal Capsules were prepared with the optimized cubosomal dispersion, by using a new technique starch and aerosil were used as granulating agents to obtain a wet mass. Then the wet mass was passed through sieve no. 16 to form granules. Then the granules were dried in hot air oven. The dried granules were filled into capsules. The granules were evaluated for SEM, zeta potential, flow properties and in vitro drug release. Optimized capsule formulation (C2) contains starch showed a maximum drug release of 49 % in 6 hours, particle size of 213nm and zeta potential of -159 mV. In vitro release kinetics exhibited sustained release up to 6 hours and followed nonFickian diffusion. Results suggest that GMO cubosomes, as lipid nanovectors, could significantly enhance oral efficacy when compared to Glimepiride powder. KEY-WORDS: Cubosomes, Glimepiride, Lyotropic liquid crystal, Glyceryl monooleate, Top-down approach, capsules, Oral drug delivery.