Definition: In this task, you're given a paragraph from the research paper and your task is to generate a suitable title for the research paper based on the given paper. Under 100 words is a good title length.
Input: Ethnopharmacological relevance: Yu Ping Feng San (YPFS, in Chinese: Jade Windscreen Powder), a wellknown traditional Chinese medicine, is commonly used to cure the diseases of respiratory systems and immune systems. Aim of the study: A selective and sensitive high-performance liquid chromatography coupled with mass spectrometry method (HPLC-MS) was developed and validated for simultaneous quantification of cycloastragenol, formononetin, calycosin, 4 0 -O-b-glucopyranosyl-5-O-methylvisamminol (GMV) and cimifugin in rat plasma after oral administration of Yu Ping Feng San decoction. Materials and methods: Plasma samples were extracted via solid-phase extraction (SPE), separated on a Zorbax SB-C18 column, detected by single quadruple mass spectrometry with an electrospray ionization interface, and quantified using selected ion monitoring mode. The current SPE-HPLC-MS assay was validated for linearity, intra-day and inter-day precisions, accuracy, extraction recovery and stability. The method was applied to a comparative pharmacokinetic study after administration of Yu Ping Feng San to rats at different doses (10, 20 and 40 g/kg). Results: The calibration curves were linear over the ranges 0.50-50 ng/mL and 17.36-1736 ng/mL. Intra-and inter-day precisions (relative standard deviations) were from 0.45% to 10.95%, and accuracy (relative recovery) from 95% to 115%. The extraction recoveries were greater than 88.42% for all analytes. Dose-dependence was shown for some constituents in the drug concentration-time profiles. Among all the active ingredients detected, cimifugin had the highest blood concentration (881-1510 ng/mL), and cycloastragenol had the longest retention time in the rat body (15.06-20.44 h). Conclusion: This analytical method is a selective, sensitive, precise, accurate, and reliable assay for simultaneous determination of cycloastragenol, calycosin, formononetin, GMV, and cimifugin in rat plasma.

Development of an SPE-HPLC-MS method for simultaneous determination and pharmacokinetic study of bioactive constituents of Yu Ping Feng San in rat plasma after oral administration