SOLID DISPERSIONS OF MODAFINIL IN POLOXAMER 188: PHYSICOCHEMICAL CHARACTERIZATION AND IN VITRO PROPERTIES
Author (s): Ruchita Kumari Patra*, Soudamini Mallik, Padala Narasimha Murthy
The rationale of the research work was to increase the solubility, hence dissolution rate of a poorly soluble drug preparing its solid dispersions. Solid dispersions of modafinil a BCS class II were prepared and evaluated for its physicochemical characteristics. Saturation solubility of modafinil was conducted using various concentrations of poloxamer 188. The Gibb’s free energy (ΔGtr0)values were all negative for carrier at various concentrations, indicating the spontaneous nature of drug’s solubilization. The Gibb’s free energy (ΔGtr0)values decreased with increased concentrations of carrier, showing that the reaction became more favorable as the carrier concentration increased. Solid dispersions of modafinil were prepared by physical mixing and melting techniques at 1:0.5, 1:1, 1:2 and 1:3 (w/w ratios of drug: carrier). The dissolution profiles of solid dispersions were compared with that of the pure drug. The solid dispersions showed improved dissolution rates than modafinil pure drug. Characterizations of solid dispersions were done by differential scanning calorimetry (DSC), X-Ray diffraction (XRD) studies and Fourier transform infra-red spectroscopy (FTIR).
Keywords: Dissolution, solid dispersions, modafinil, poloxamer 188, solubility increase.