Preparation and evaluation of novel blend microspheres of poly(lactic‐<i>co</i>‐glycolic)acid and pluronic F68/127 for controlled release of repaglinide

Abstract

Abstract The objective of the present work was to study the release behavior of plain and blend microspheres (MS) of PLGA and Pluronic F68/127. In this study, a novel blend MS of poly( D , L ‐lactic‐ co ‐glycolic acid) (PLGA) and Pluronic F68/127 (PLF68/127) were prepared by the emulsion–solvent evaporation method. Repaglinide, an antidiabetic drug with a very short half‐life, was successfully encapsulated into the blend MS. Various formulations were prepared by varying the ratio of PLGA and PLF68/127. Drug encapsulation up to 91% was achieved as measured by UV spectroscopy. Scanning electron microscopy showed that MS have smooth surfaces even after incorporation of PLF68/127. Particle size, as measured by using laser light scattering technique, gave an average size ranging from 12 to 47 μm. Differential scanning calorimetry (DSC) was performed to understand the crystalline nature of the drug after encapsulation into MS. DSC revealed the crystalline dispersion in the polymer matrix. In vitro release experiments performed in simulated intestinal fluid, indicated the dependence of release rate on the amount of PLF68/127 present in the MS; slow release was extended up to 153 h. Release data have been fitted to an empirical equation to compute the diffusional exponent ( n ), which indicated that the release mechanism to be non‐Fickian type. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2010