Preparation of porous PLGA microspheres with thermoreversible gel to modulate drug release profile of water-soluble drug: Bleomycin sulphate

Bleomycin sulphate-loaded porous microspheres were prepared using modified solvent evaporation method (w/o/w) using PLGA50: 50 as a polymeric system. The prepared microspheres were incorporated in pluronic (R) (F127) based thermoreversible gel to develop a depot formulation. Various process parameters as solvent evaporation temperature and formulation parameters such as surfactant concentration, volume of internal and external phase and drug-to-polymer ratio were optimized for enhancing percentage drug entrapment, percentage drug loading and desired release profile by controlling size and porosity of the microspheres. Microspheres were characterized for particle size, zeta potential, surface morphology, percentage drug loading and in vitro drug release study after incorporated in gel. The formulated microspheres were porous in nature and showed biphasic in vitro drug release profile. The microspheres incorporated in pluronic((R)) (F127) gel showed sustained release up to 1 week and may be useful for treatment of squamous cell carcinoma with better therapeutic effect.