Polymeric Microparticles as Alternative carriers for Antidiabetic Glibenclamide Drug

Glibenclamide is a lipophilic drug molecule widely used in type II Diabetes treatment. Its low bioavailability limits its use; thus, novel formulations should be applied to improve it. This study aimed to develop alternative carriers for oral delivery of Glibenclamide. For this purpose, two biocompatible polymers  of poly(e-caprolactone) and poly(butylene adipate) were formulated as microparticles (MPs) capable to load the antidiabetic drug. In this regard, a microparticle fabrication approach as a modified emulsion-solvent evaporation method was applied. Physicochemical evaluation of the prepared MPs included the examination of their morphology, degradation rate and thermal properties. Drug entrapment, drug loading and particle size were also investigated. Simulated intestinal medium and simulated body fluid at 37 oC were selected as dissolution media. Differential Scanning Calorimetry (DSC) was used to investigate the crystal properties of the MPs and drug. The developed MP size was between 0.5 and 4 μm. Poly(butylene adipate) MPs had a smooth surface whereas poly(ε-caprolactone) MPs showed a porous surface. The DSC thermogram demonstrated the amorphization of the drug. Hydrolysis results showed very low mass loss, while in-vitro release results showed that the dissolution rate of MPs was higher than that of pure Glineclamide and prolonged pattern which is ideal to minimize the daily dose of Glibenclamide. In this study, novel carriers for Glibenclamide were successfully prepared and characterized revealing their possible future use.