[Freeze-drying of oleanolic acid-loaded nanosuspensions].
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.


METHODS
The protective effect was evaluated by measuring the mean particle size of samples before and after freeze-drying process.


RESULTS
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).


CONCLUSIONS
The optimum lyophilized powder could be obtained with suitable type of cryoprotectant with appropriate concentration and proper freeze-drying conditions.
Zhao
Xiao-Ling
XL
Department of Chemistry, Wuhan 430074, China.
Chen
Hua-Bing
HB
Chen
Ya-Jun
YJ
Yang
Xiang-Liang
XL
D003451:Cryoprotective Agents / Q000737:chemistry / Q000494:pharmacology; D004355:Drug Stability; D005612:Freeze Drying / Q000379:methods*; D046529:Microscopy, Electron, Transmission; D053758:Nanoparticles / Q000737:chemistry* / Q000648:ultrastructure; D009828:Oleanolic Acid / Q000737:chemistry*; D010316:Particle Size; D012995:Solubility / Q000187:drug effects; D013395:Sucrose / Q000737:chemistry / Q000494:pharmacology; D013535:Suspensions
D003451:Cryoprotective Agents; D013535:Suspensions; D013395:Sucrose; D009828:Oleanolic Acid