Encapsulation of Repaglinide into Eudragit Rs Microspheres and Modulation of Their Release Characteristics by Use of Surfactants

Microspheres containing Repaglinide was prepared by emulsion solvent evaporation technique using two types of surfactants Tween 80 (polysorbate 80) and Span 80 (Sorbitanmonooleate 80). The effect of change in the type and surfactant amount on the size and drug release from the microspheres was investigated. The release of Repaglinide from the microspheres exhibit diffusional characteristics and closely follows Higuchi Model and also highly correlated with first-order release model. The in-vitro release study was performed in pH 6.8, phosphate buffer Solution and 0.1N HCl. Scanning electron microscopy study revealed that the microspheres were spherical and porous in nature. In vivo testing of the microspheres in diabetic albino rats demonstrated significant antidiabetic effect of Repaglinide. Repaglinide loaded microspheres expected to give new choice for safe, economical formulation for effective management of NIDDM. A clear correlation between the types of surfactant on mean diameter of the microspheres was found. When Span 80 was used, the microspheres were smaller in size as compared to those obtained using Tween 80, while there was a higher release rate when Tween 80 was used. INTRODUCTION: Microspheres are one of the multiparticulate delivery systems and are prepared to obtain prolonged or controlled drug delivery. Microspheres can also offer advantages like limiting fluctuation within therapeutic range, reducing side effects, decreasing dosing frequency and improving patient compliance 1 . Eudargit RS 100 is water insoluble polymer that is widely used as a wall material for sustained release microspheres. QUICK RESPONSE CODE DOI: 10.13040/IJPSR.0975-8232.8(9).3936-47 Article can be accessed online on: www.ijpsr.com DOI link: http://dx.doi.org/10.13040/IJPSR.0975-8232.8 (9).3936-47 This is due to its biocomptability, good stability, easy fabrication and low costs 2 . Repaglinide is an oral hypoglycemic agent and first member of meglitinide class, used to treat type-2 diabetes mellitus. It blocks the ATP dependent potassium channel to stimulate release of insulin by binding to specific site on pancreatic b-cells (Van Gall et al.,