OBJECTIVE: Several cryoprotectants were employed to study the protective effect on the freeze-drying process of the oleanolic acid-loaded nanosuspensions (OLA-LS) in order to select the optimum formulation. METHOD: The protective effect was evaluated by measuring the mean particle size of samples before and after freeze-drying process. RESULT: Sucrose with the concentration of 10% was selected as the optimum cryoprotectant. The average size of excellent sample was 236.3 nm (versus 211.2 nm of fresh one), and a much higher polydispersity index of 0.242 (versus 0.180). CONCLUSION: The optimum lyophilized powder could be obtained with suitable type of cryoprotectant with appropriate concentration and proper freeze-drying conditions.
OBJECTIVE: Several cryoprotectants were employed to study the protective effect on the freeze-drying process of the oleanolic acid-loaded nanosuspensions (OLA-LS) in order to select the optimum formulation. METHOD: The protective effect was evaluated by measuring the mean particle size of samples before and after freeze-drying process. RESULT: Sucrose with the concentration of 10% was selected as the optimum cryoprotectant. The average size of excellent sample was 236.3 nm (versus 211.2 nm of fresh one), and a much higher polydispersity index of 0.242 (versus 0.180). CONCLUSION: The optimum lyophilized powder could be obtained with suitable type of cryoprotectant with appropriate concentration and proper freeze-drying conditions.