Polycaprolactone-based neurotherapeutic delivery of rasagiline targeting behavioral and biochemical deficits in Parkinson's disease.

Rasagiline mesylate is an irreversible MAO-B inhibitor which requires daily oral administration for treatment of Parkinson's disease due to its short half-life. Patients with Parkinson's disease also develop dysphagia, i.e., difficulty in swallowing. Encapsulating rasagiline in polycaprolactone microspheres can alleviate the problem of daily oral administration by prolonging drug release from polymeric microspheres for 1 month by single subcutaneous administration. Polycaprolactone shows absence of any acidic environment generation during its degradation in body which is its advantage over poly (lactic-co-glycolic) acid. Exploiting pH-based solubility of rasagiline mesylate pH changes during microencapsulation process was performed to fabricate rasagiline mesylate-loaded polycaprolactone microspheres. Particle size analysis of microspheres showed mean particle size range of 24.18-47.87 μm. Scanning electron micrographs revealed spherical non-porous particles with small pits and depressions on the surface. In vitro release studies of formulations were performed to get an idea about in vivo behavior of prepared formulations. Stereotaxic rotenone model was used to study in vivo efficacy of formulation in rats. Selected formulation significantly (p < 0.05) improved various behavioral (locomotor activity, grip strength, etc.) and biochemical (lipid peroxidation, reduced glutathione, etc.) changes. Polymeric microspheres showed robust effect on all outcomes assessed with non-significant difference between daily administration of rasagiline mesylate solution and drug-loaded polymeric microspheres administered once in a month. With prepared controlled release injectable once a month, administration is required making it an interesting and convenient approach in treatment of Parkinson's disease with dysphagia. Patient compliant system can be achieved by exploiting this approach for future use.