Investigation And Determination Of Artemisinin By HPLC With Coularray Detector

Objective:To establish HPLC-ECD chromatograpH determined Artemisinin method. Using this method measure the solubility of Artemisinin in different solvents, its oil-water distribution coefficients and low concentration biological samples. Through this data preliminary speculate the influence factors of Artemisinin bioavailability.This study may offer helpful reference for study of the preparations of Artemisinin.Method:Using the uniform experimental design method to determine a good derivative method. The examine factors include:the NaOH amount, the acetic dosage, the water bath temperature and time. To choose a suitable measuring conditions through investigate the ratio of mobile pHase, the value of pH, the detection voltage and the Column temperature. Using this method to determine the solubility of Artemisinin in different solvents, its oil-water distribution coefficients, the low concentration of plasma biological samples and so on. From all above these data analyze which can preliminarily infers the biopHarmaceutical parameter of Artemisinin. This useful information will direct the preparations which can improve the bioavailability of Artemisinin.Results:Through to analyze the results of experiments, the best group of derivative method is as follows:1mL Artesunate ethanol liquid added 4mL 0.01mol·L-1 NaOH, at the 70℃thermostatic water bath pot reaction 50min, then remove the sample and rapid cooling to room temperature, at last added 5mL 0.06mol·L-1 acetic. The acetic is not significant for the results, so according to the test conditions the acetic dosage can adjustment. Determine biological samples, the amount of derivative agent is change from 1:4:5 to 0.5:2:2.5, the acetic acid concentration is adjusted for 0.02 mol·L-1. The linear range of ordinary Artemisinin samples by HPLC-ECD is 50μg·mL-1～0.1μg·mL-1. The linear range of Artemisinin biological samples by HPLC-ECD is 16.32 ng·mL-1～2.04μg·mL-1. The result shows that the solubility of Artemisinin in water at 25℃is only 0.0671mg·mL-1. To use the chloroform as oil pHase, Artemisinin oil-water distribution coefficient is 732.03, 1gP=2.86; When using n-butyl alcohol as the oil pHase, the oil-water distribution of Artemisinin is 184.09, 1gP=2.27. In plasma biological samples from mice, the Artemisinin content is about 150ng·mL-1 at 30min, according to principle of balance research, roughly determined the body absorbs of Artemisinin is 92%.Conclusion:Based on the content of Artemisinin samples and methodology investigation the HPLC-ECD chromatograpHic method suitable for low concentration of biological samples quantitatively determined. According to Analyze on the measurement data, it is preliminarily presumed that Artemisinin may belong to biopHarmaceutical classification systemⅡtype drug. The low bioavailability may caused by dissloution and first pass effect. The conclusion has important directive meaning to research the preparation of improve Artemisinin bioavailability.