Dissolution determination of five components in Huoxiang Zhengqi tablets using partitioned dispersive liquid-liquid microextraction combined with HPLC-UV

The dissolution determination of multiple components in herbal preparations is a crucial method for controlling the quality of oral solid dosage forms. In order to improve the low detection sensitivity of dissolution samples, an efficient method for the extraction and concentration of multiple components in dissolution samples of Huoxiang Zhengqi tablets was developed by partitioned dispersive liquid-liquid microextraction (PDLLME). In the PDLLME process, 1.6 mL of THF as the disperser solvent and 100 mu L of 1,2-dichloroethane as the extraction solvent were injected into 8 mL of the dissolution sample solution. Based on the partition coefficient, a portion of THF will transfer into the extraction solvent, then the multiple components in the Huoxiang Zhengqi tablet can be extracted into the mixture extraction phase of 1,2-dichloroethane and partitioned THF. In combination with HPLC-UV analysis, the enrichment factors reached to 43 to 119-fold for five of the target components (three of the more polar components were unknown). For honokiol and magnolol, a linear range from 10 to 1000 mu g L super(-1) was obtained, and the recoveries at three spiking levels ranged from 90.2 to 99.4% with RSD less than 7.2% (n= 3). The proposed method may be applied for the extraction and concentration of multiple components in the dissolution samples of other herbal preparations.