Formulation & evaluation of baclofen loaded sustained release microspheres using HPMC-k4m

This study aimed to develop and evaluate floating microspheres of Baclofen to enhance its gastric retention and prolong its release within the upper gastrointestinal tract. The microspheres were formulated using the solvent evaporation method. A 32 full factorial design was employed to investigate the combined effects of two independent variables: the concentration of PLGA (X1) and PEO (X2), on the dependent variables such as particle size (Y1), drug entrapment efficiency (Y2), buoyancy (Y3), in-vitro drug release at 1 hour (Y4), and in-vitro drug release at 6 hours (Y5). The results from multiple regression analysis indicated that increasing the concentrations of PLGA and PEO led to a decrease in drug release, while particle size, entrapment efficiency, and buoyancy increased. The optimized formulation demonstrated a particle size of 115.96 µm, a drug entrapment efficiency of 90.06%, and buoyancy of 90.76%. The in-vitro release profile of Baclofen from the floating microspheres exhibited sustained drug release for up to 24 hours. The microspheres were found to be free-flowing, porous, and nearly spherical. The release kinetics followed the Higuchi model, with drug release governed by Fickian diffusion.