Formulation and evaluation of microspheres containing ropinirole hydrochloride using biodegradable polymers

The present work relates with developing long acting sustain release microspheres of ropinirole hydrochloride (RPN) for treatment of Parkinson′s disease, that will sustain drug release up to 1 month. Biodegradable microspheres of RPN were prepared by using two different polymers (poly lactic co glycolic acid [PLGA] 50:50 and PLGA 75:25) employing double emulsion (W/O/W) solvent evaporation method. Preliminary optimization of process parameter was done for concentration of polyvinyl alcohol (PVA) solution, stirring speed, temperature of PVA solution, ratio of the drug to polymer (D/P) and ratio of internal phase to external phase volume (IP/EP). All formulations were evaluated for particle size, percentage yield, entrapment efficiency (EE), shape etc. Formulation E3 and E4 shows maximum EE. % in vitro drug release per day of E3 and E4 batch was studied. The RPN was incorporated successfully in microspheres prepared with 0.5% w/v PVA at 8000 RPM stirring speed, 20°C processing temperature, 1:4 drug polymer ratio and 1:30 IP/EP ratio, which provides sustained release up to 4 weeks with better efficacy and patient compliance and can be employed as an alternative to existing oral medications.