Abstract: The purpose of this paper is to investigate the morphology change and crystalgrowth of fine particles of beclomethasone diopropionate (BDP), its ethyl acetate solvate (BDP-EtOAc) and trichlorofluoromethane solvate (BDP-P11) after contacting trichlorofluoromethane.Curves of crystal growth versus time were obtained and kinetic parameters of crystal growth were calcu1ated. The tendency and velocity of crystal growth were BDP>BDP-EtOAC>BDP-P11. K-values of crystal growth curves for BDP at 15℃ and BDP-EtOAc at 40 ℃ were 0.1637 μm·min^-1 and 0.0138 μm·min^-1 respectively. Final particle sizes of BDP were calculated and compared with measured values. Results of twin liquid impinger tests showed that BDP pressurized metered dose inhaler (pMDIs) prepared with BDP, BDP-EtOAc and BDP-P11 had deep lung drug deposition of 8%, 54% and 59%, dropping to 2%, 40%, and 57% after storage at 40℃, 75% RH for 2 weeks respectively.

Key words: Beclomethasone diopropionate, Solvates, Crystal growth, Kinetic parameter, Performance of inhalations