Potential of microemulsified entacapone drug delivery systems in the management of acute Parkinson's disease

Abstract Objective To design solid self-microemulsifying drug delivery system (S-SMEDDS) of entacapone and evaluate for its anti-Parkinson's potentials. Methods Solubility studies were performed in various vehicles i.e. , oils, surfactants and co-surfactants and pseudo-ternary phase diagrams were plotted to understand the microemulsion formation region. Liquid self-microemulsifying drug delivery systems (SMEDDS) were developed using gingelly and rice bran oil as lipid vehicles, Tween 80 and Span 20 as surfactants and glycerin, propylene glycol as co-surfactants. They were characterized by Fourier transform infrared spectroscopy, pH, viscosity, zeta potential, polydispersibility index and droplet size analysis and evaluated for drug content, in-vitro release, in-vitro diffusion and ex-vivo permeation. Optimized liquid SMEDDS were converted into S-SMEDDS by adsorption and melt granulation procedures. Characterization by differential scanning calorimetry, SEM, micrometrics, reconstitution property, moisture content and evaluation by drug content, drug release kinetics and shelf-life were performed for S-SMEDDS. Parkinsonism was induced and pharmacodynamic potentials of S-SMEDDS were evaluated. Results S-SMEDDS formulation AG8 had shown the highest drug release of 90.92% within 60 min. Pharmacodynamic studies also proved the efficiency of entacapone S-SMEDDS against Parkinsonism. Conclusions Entacapone S-SMEDDS is an effective drug delivery system that offers more predictable and extensive drug release with enhanced shelf-life in the treatment of acute Parkinsonism.