Enhancement of Solubility of Artemisinin and Curcumin by Co-Solvency Approach for Application in Parenteral Drug Delivery System

The aim of present study was to enhance solubility of poorly soluble antimalarial drugs, Artemisinin and Curcumin by adopting  Co-solvency approach and to develop parenteral aqueous injectable solution. Solubility enhancement of both drugs was achieved using co-solvency approach. The parenteral injection was prepared by using a ternary co-solvent system which comprised of benzyl alcohol, PEG 400 and tween 80 (as surfactant). Solubility of Artemisinin and Curcumin was found to be higher in benzyl alcohol and PEG 400. Co-solvent system comprising of  benzyl alcohol, PEG 400 and tween 80 in volume fraction of 0.3, 0.9 and 0.2 respectively showed the minimum required solubility of Artemisinin (90 mg per ml) and Curcumin (180 mg per ml). The parenteral injectable formulation was characterized for pH, clarity, viscosity, osmolarity and sterility and the stated parameters were found in acceptable range.  In-vitro erythrocyte toxicity study showed that intravenous administration of optimized formulation will be safe. In-vitro antimalarial assay indicated that efficacy of artemisinin and curcumin parenteral formulation was greater than quinine and combination of Artemether and Lumefantrine. Stability study of the optimized batch showed no change in physical and chemical characteristics. Based on study, one can conclude that Artemisinin and Curcumin can be successfully formulated as parenteral injectable formulation by co-solvency approach for the effective treatment of malarial infection