Solubility Enhancement of Lumefantrine by Hot Melt Extrusion Process

Lumefantrine is a BCS class -II drug having a poor aqueous solubility. There is a need for improvement in solubility, in order to enhance the therapeutic efficacy and reduce the dose. Hence in the present work, the solubility of lumefantrine is enhanced by formulating solid dispersions of lumefantrine using a hot melt extrusion process in a twin-screw processor using three different polymers such as Kollidon VA64, Soluplus and HPMC AS at a weight ratio of 1:2, 1:3 and 1:4, processed at different barrel temperatures and screw speeds. The obtained solid dispersions were characterized by differential scanning calorimetry and solubility studies. Solid dispersions prepared with KollidonVA64 and Soluplus showed a clear extrudate indicating a complete amorphous conversion of the lumefantrine at all the three ratios evaluated. Increase in polymer concentration, increased the solubility of the lumefantrine. With Kollidon VA 64 and Soluplus, lumefantrine to polymer ratio of 1:4 showed the highest increase in solubility, compared to that of the pure lumefantrine.