Poly-e-caprolactone-loaded miglitol microspheres for the treatment of type-2 diabetes mellitus using the response surface methodology

ObjectivesTo formulate and characterize miglitol (MGL)-loaded microspheres as a drug delivery system for oral administration to prolong the duration of action for achieving reductions of multiple doses. MGL, an oral antihyperglycaemic agent, possesses a short elimination half-life of 2 h, so it must be administered in multiple doses.MethodsA 32 full factorial design was employed for microsphere formulation using the solvent evaporation technique. The influences of two independent variables, the polymer and surfactant concentrations, on dependent variables, such as drug loading (DL) and the encapsulation efficiency (EE), were statistically investigated using Design Expert Software. Microspheres were characterized using field emission scanning electron microscopy (FE-SEM), Fourier transform infrared spectrophotometry (FTIR), and X-ray diffraction (XRD) and were evaluated for their in vitro drug release and stability at accelerated conditions.ResultsThe statistical evaluation of the design showed quadratic and linear models as significant models for DL (R2: 0.9932) and EE (R2 0.9696). The sizes of particles ranged from 54.7 μm to 140 μm, and the particles were spherical in shape with coarse surfaces. The most significant factor was the polymer amount. FTIR and XRD studies confirmed the drug-polymer compatibility. In vitro release of MGL from polymeric microspheres was found to occur a slower rate of up to 10 h.ConclusionThe developed poly-e-caprolactone-loaded MGL microspheres can be successfully formulated. These microspheres can provide a promising sustained release drug delivery system for the treatment of hyperglycaemia associated with type-2 diabetes mellitus.