Silymarin Loaded Floating Polymer(S) Microspheres:Characterization, In-Vitro/In-Vivoevaluation

Silymarin has a short half-life (4-6 hours) which leads to necessity of frequent administration. Besides, it suffers from intestinal degradation. Thus, our study aims to formulate encapsulated floating microspheres using different polymers as HPMC, EC and a blend of them. Emulsion solvent evaporation technique was applied for preparation of microspheres. Parameters considered during preparation are drug: polymer ratio and emulsifier concentration. Selected formulations were characterized by SEM and subjected for assessment by drug entrapment efficiency, buoyancy for 12 hr,in- vitrodrug release, kinetics of release and stability.In-vivobio-equivalence study was performed using albino rabbits. Formula F24 (treatment II) exhibited high % buoyancy (73.4), higher t(90)(190.7 day), high C-max(1021.3 ng/ml) and T-max(6 h) with a significant difference between it and treatment I (Silymarin plus) after carrying out ANOVA study. Also formula F24 exhibited MRT (hr) equal 9.44 +/- 0.03 and high relative bioavailability RB% (227%), which indicates promising microspheres that could be used for effective management of liver disease.