Objective To prepare memantine hydrochloride sustained release tablets and determine the factors affecting the drug release behaviors in vitro,and to explore the pharmacokinetics of the tablets in Beagle dogs.Methods We used single factor experiments to determine the factors that influenced the drug release.The similar factors of in vitro release data of self-made tablets and com. available tablets were used as evaluation indexes to optimize the formulation of memantine hydrochloride sustained release tablets by orthogonal design.Results The amount of HPMC K100M,HPMC E50,PEG 4000 and the weight gain of the coating had a significant effect on the drug.The self-made sustained release tablets of memantine hydrochloride were released slowly and stably within 12 h,which was consistent with the zero-order release model.The self-made sustained release preparation of memantine hydrochloride and the reference preparation were bioequivalent with similar blood concentration-time curve in Beagle dogs,and the relative bioavailability was 94.92%.Conclusion The self-made memantine hydrochloride sustained release tablets are stably released in vitro and show good pharmacokinetic characteristics in vivo.