Research on core Chinese materia medica and herb compatibility in syndrome differentiation and treatment of insomnia based on CNM-centrality algorithm / 中草药

Using node centrality evaluation algorithms and clustering algorithms in complex networks, this paper selects insomnia as study object, and explores the core Chinese materia medica (CMM) and CMM compatibility regularity of syndrome differentiation and treatment. Firstly, we construct the CMM network model of insomnia, and discover the core CMM nodes in this network using single-index evaluation algorithms. Then, the CMM network can be divided by the clustering algorithm CNM-centrality based on node centrality, and the compatibility regularity among CMM can be found accurately.

Simultaneous HPLC-MS/MS determination of losartan potassium and its metabolite E-3174 in human plasma and its application to pharmacokinetic study / 中国药学杂志

OBJECTIVE: To develop a sensitive and rapid HPLC-MS/MS method for the determination of losartan potassium and E-3174 in human plasma. METHODS: The plasma samples were extracted with methyl tert-butyl ether (MTBE) after addition of internal standard and acetic acid, and then analyzed with API 3000 LC-MS/MS system. The analytical column was SHISEIDO, CAP-CELL PAK C18 MG II (2.0 mm × 50 mm, 5 μm) and the column temperature was room temperature. The mobile phase was composed of 0.1% formic acid in water (containing 5 mmol·L-1 ammonium acetate) -0.1% formic acid in acetonitrile (20:80) and the flow rate was 0.85 mL·min-1. Detection was performed with multiple reactions monitoring (MRM) using positive electrospray ionization (ESI). RESULTS: The calibration curves were linear over the concentration ranges of 10.10-2525 ng·mL-1 for losartan potassium and 9.820-2455 ng·mL-1 for E-3174, respectively. The lower-limit-of-quantifications were 10.10 ng·mL-1 for losartan potassium and 9.820 ng·mL-1 for E-3174, respectively. Inter-and intra-day precisions were less than 9.22% and accuracy was within 93.56%-102.88%. Extraction recoveries were around 70% and the analytes were proved to be stable. Total run time of an analyte was only 2.5 min. The relative bioavailabilities of the two preparations were 96.5% for losartan potassium and 110.0% for E-3174. These two losartan potassium preparations were bioequivalent. CONCLUSION: This method is rapid, sensitive, specific and applicable to the pharmacokinetic study in human and bioequivalence study of losartan potassium.