Development of vildagliptin loaded Eudragit® microspheres by screening design: in vitro evaluation

The aim of this study was to develop and characterize sustained release vildagliptin (VLG) loaded Eudragit® RS-100 microspheres. The microspheres were prepared by single emulsion [oil-in-oil (O/O)] solvent evaporation method. Plackett–Burman design (PBD) was employed by using Design-Expert® Software to screen and understand impact of five independent formulation factors such as Eudragit® RS-100 (A), span-80 (B), acetone (C), methanol (D), stirring speed (E) affecting on encapsulation efficiency (EE) and dissolution rate (DR). The developed microspheres were evaluated by Field emission scanning electron microscopy (FE-SEM); particle size analyzer (PSA); Fourier transform infrared spectroscopy (FTIR); X-ray powder diffraction (XRD) and in-vitro drug release as well as microspheres were assessed for accelerated stability. The microspheres obtained were spherical in shape with non-porous surface and the mean particle size was 1.077 µm. FTIR and XRD study confirmed drug-polymer compatibility. EE obtained from all microspheres formulations was found in the range of 61.83–84.77%. 2D contour and 3D surface plots showed potential effects of independent factors on EE and DR. Sustained drug release profile (up to 12 h) was attained by Eudragit® RS100 polymer. Accelerated stability results for attributes like physical appearance and drug content did not showed any significant change over the period. Eudragit® RS-100 polymer could be used as favourable sustained release carrier in developing VLG loaded microspheres for the treatment of hyperglycemia to increase its duration of action. © 2017, The Korean Society of Pharmaceutical Sciences and Technology.