Formulation development and optimization of artemether-lumefantrine self-nanoemulsifying drug delivery systems

Poor aqueous solubility may decrease the absorption and oral bioavailability of lipophilic drugs. In the current study, artemether (ART) and lumefantrine (LMF) o/w self-nano emulsifying drug delivery system (SNEDDS) formulations were prepared. Equilibrium solubility studies were conducted and pseudo-ternary phase diagrams were constructed to identify excipients with the best solubilizing capacity for ART and LMF. They were subsequently used to manufacture and optimize SNEDDS using experimental designs, which were then characterized. Solubility and emulsification studies revealed that ART and LMF are highly soluble in oleic acid (OA). Cremophor^® EL (CEL) and Transcutol^® HP (THP) were selected as surfactant and co-surfactant. The addition of Capryol™ 90 (C90) increased the region of nano-emulsion formation without evidence of precipitation of ART and LMF. Compatibility studies revealed no prominent or significant incompatibilities between the drugs and selected excipients. The optimized formulation was stable as dispersions with nano-sized droplets and a loading capacity >99 % for both ART and LMF and a release >95% within 15 min for both drugs, reflecting a significant increase in the rate and extent of dissolution compared to that of the pure drug.