Fabrication of drug nanoparticles by evaporative precipitation of nanosuspension.

Evaporative precipitation of nanosuspension (EPN) was used to fabricate nanoparticles of a poorly water-soluble antimalarial drug, artemisinin (ART), with the aim of enhancing its dissolution rate. We investigated the nanoparticle fabrication of ART via a full factorial experimental design considering the effects of drug concentration and solvent to antisolvent ratio on the physical, morphological and dissolution properties of ART. Characterization of the original ART powder and EPN prepared ART nanoparticles was carried out by scanning electron microscopy, differential scanning calorimetry (DSC), X-ray diffraction (XRD) and dissolution tester. DSC and XRD studies suggested that the crystallinity of EPN prepared ART nanoparticles decreased with increasing drug concentration and ratio of solvent to antisolvent. The particle diameters of EPN prepared ART nanoparticles were found to be 100-360 nm. The dissolution of EPN prepared ART nanoparticles markedly increased as compared to the original ART powder. A percent dissolution surface-response model was used to elucidate the significant and direct relationships between drug concentration and solvent to antisolvent ratio on one hand and percent dissolution on the other hand. The best dissolution percent was found to be 75.9%, at the drug concentration of 15 mg/mL and solvent to antisolvent ratio (by volume) of 1:20.