Solid Dispersion of Lumefantrine Using Soluplus® by Solvent Evaporation Method: Formulation, Characterization and in-vitro Antimalarial Screening

Objectives: Lumefantrine (LUM) is an antimalarial drug having poor aqueous solubility. The objective was to formulate the solid dispersion of LUM and improve the solubility and dissolution rate. Materials and Methods: Solvent evaporation technique was used to prepare solid dispersions (SDs) with Soluplus® (SOL) using a rotary evaporator. The feasibility of the formation of SD for LUM and SOL was assessed by the Hansen solubility parameter. The drug solubility was analyzed by the HPLC method and the ratio of LUM: SOL was optimized to 1:2. The SD was characterized by DSC, FTIR, XRD and SEM. Results: The results showed that the LUM and SOL had groups that lead to the interaction between them and this led to conversion from crystalline to amorphous form and thus improved the dissolution rate. The solubility of L2 was found to be 135 ± 3.3 μg/mL using the selected dissolution media (0.1 N HCl+1% Myrj 52). The in-vitro antimalarial screening was performed using the P. falciparum 3D7 strain and the in-vitro cytotoxicity test was performed using the Vero cell line. The higher antimalarial efficacy of L2 SD was observed as compared to plain LUM. The selectivity index value of LUM SD depicted its non-toxicity. Stability study was carried out for three months and the SDs were evaluated for the drug content, change in weight and in-vitro drug release. No significant changes were observed after three months in the drug content, SD weight and in-vitro drug release. Thus the L2 SD was found to be stable. Conclusion: The prepared SD improved the solubility as well as the dissolution rate of the drug.