Formulation, In Vitro and In Vivo Evaluation of Gefitinib Solid Dispersions Prepared Using Different Techniques

Gefitinib (Gef) is a poorly water-soluble antitumor drug, which shows poor absorption/bioavailability after oral administration. Therefore, this study was carried out to develop Gef solid dispersions (SDs) using different carriers and different techniques in order to enhance its dissolution and oral absorption/bioavailability. Various SD formulations of Gef were established using fusion and microwave methods utilizing Soluplus, Kollidone VA64, and polyethylene glycol 4000 (PEG 4000) as the carriers. Developed SDs of Gef were characterized physicochemically and evaluated for in vitro dissolution and in vivo pharmacokinetic studies. The physicochemical evaluation revealed the formation of Gef SDs using fusion and microwave methods. In vitro dissolution studies indicated significant release of Gef from all SDs compared to the pure Gef. Optimized SD of Gef (S2-MW) presented significant release of Gef (82.10%) compared with pure Gef (21.23%). The optimized Gef SD (S2) was subjected to in vivo pharmacokinetic evaluation in comparison with pure Gef in rats. The results indicated significant enhancement in various pharmacokinetic parameters of Gef from an optimized SD S2 compared to the pure Gef. In addition, Gef-SD S2 resulted in remarkable improvement in bioavailability compared to the pure Gef. Overall, this study suggested that the prepared Gef-SD by microwave method showed marked enhancement in dissolution and bioavailability.