Aim of this study was to prepare Bu-Yang-Huan-Wu (BYHW) elementary osmotic pump sustained-release tablets and to investigate the situation of its main effective components of “synchronous control and sustained release.” The releasing similarity of chromatographic fingerprints of BYHW in vitro dissolution was evaluated. The results showed that BYHW elementary osmotic pump sustained-release tablet was prepared and the chromatographic fingerprints were extracted. And data of its release similarity was also obtained. It was concluded that BYHW el...