Nanonization of Megestrol Acetate by Liquid Precipitation

The purpose of this study was to prepare megestrol acetate (MA) nanoparticles via a liquid precipitation technique. Several experimental parameters, such as the stabilizer combination, the volume ratio of antisolvent to drug solution, the temperature, the stirring speed, and the drying method were investigated. The as-prepared MA particles had a mean size of 208 nm, and 90% of the particles were distributed in the range of 100-300 nm, whereas the raw MA had a mean particle size of about 3.02 mu m, ranging widely from 0.2 mu m to 30,mu m. X-ray diffraction (XRD), differential scanning calorimetry (DSC), and Fourier transform infrared (FTIR) analysis indicated that MA nanoparticles exhibited decreased crystallinity and unchanged chemical group structure after precipitation. The freeze-dried MA nanoparticles exhibited improved wettability as demonstrated by the contact angle measurement result proving that particles were covered by a hydrophilic layer. In dissolution rate tests, the nanoparticles achieved 100% drug dissolution within 5 min, while the raw MA did not dissolve completely after 120 min, suggesting that the dissolution property of MA nanoparticles was significantly enhanced.