OBJECTIVE To prepare and evaluate donepezil sustained-release microspheres by ultrasound technique.METHODS Preparation technology of donepezil biodegradable microspheres by ultrasound technique was established and optimized.In vitro evaluation of donepezil microspheres was carried out.The pharmacokinetics of donepezil microspheres was investigated by LC-MS / MS after subcutaneous injection in rabbits at a dose of 30.0 mg·kg-1.RESULTS Donepezil microspheres with drug loading of 12.1% and mean particle size between 40 to 130 μm were successfully prepared by ultrasound technique.The donepezil microspheres displayed a one-month sustained-release character in vitro.The pharmacokinetic parameters were as follows:ρmax 40.63 μg·L-1,t max 2.47 d,MRT 14.81 d,and AUC 0→∞ 646.96 μg · d · L-1.CONCLUSION Ultrasound technique is successfully applied in the preparation of donepezil sustained-release microspheres.