Simultaneous quantification of chlorogenic acid and taurocholic acid in human plasma by LC-MS/MS and its application to a pharmacokinetic study after oral administration of Shuanghua Baihe tablets / 中国天然药物

An LC-MS/MS method was developed and validated for the simultaneous quantification of chlorogenic acid (CGA) and taurocholic acid (TCA) in human plasma using hydrochlorothiazide as the internal standard. The chromatographic separation was achieved on a Hedera ODS-2 column with a gradient elution using 10 mmol·L(-1) of ammonium acetate buffer solution containing 0.5% of formic acid - acetonitrile as mobile phase at a flow rate of 300 μL·min(-1). The detection was performed on a triple quadrupole tandem mass spectrometer by multiple reaction monitoring in negative ESI mode. The method was fully validated over the concentration ranges of 0.1-10 ng·mL(-1) for CGA and 2-150 ng·mL(-1) for TCA. It was successfully applied to a pharmacokinetic study of CGA and TCA in healthy Chinese volunteers after oral administration of Shuanghua Baihe tablets (SBTs). In the single-dose study, the maximum plasma concentration (Cmax), time to reach Cmax (Tmax) and elimination half-life (t1/2) of CGA were (0.763 8 ± 0.542 0) ng·mL(-1), (1.0 ± 0.5) h, and (1.3 ± 0.6) h, respectively. In the multiple-dose study, the Cmax, Tmax and t1/2 of CGA were (0.663 7 ± 0.583 3) ng·mL(-1), (1.1 ± 0.5) h, and (1.4 ± 0.7) h, respectively. For TCA, no significant characteristic increasing plasma TCA concentration-time curve was found in the volunteers after oral administration of SBTs, indicating its complicated process in vivo as an endogenous ingredient.

Quantitative determination and pharmacokinetics of retinamido-ester in rat plasma by liquid chromatography-atmospheric pressure chemical ionization-tandem mass spectrometry / 药学学报

A highly sensitive, rapid and selective liquid chromatography-tandem mass spectrometry (LC-MS/MS) method for the quantitative determination of retinamido-ester in rat plasma was developed and validated. A simplified protein precipitation with acetonitrile was employed for the sample preparation. The separation was carried out on an Agilent TC C18 column (150 mm x 4.6 mm ID, 5 microm particle size) with the mobile phase consisted of methanol-water-formic acid (93: 7: 0.1). Simvastatin was used as internal standard. The detection was performed on a trap-quadrupole tandem mass spectrometer by selected reaction monitoring (SRM) scan mode via atmospheric pressure chemical ionization (APCI). The range of calibration curve was 0.05-50 ng x mL(-1) and the limit of quantification was 10 pg x mL(-1). The intra- and inter-day precision values were between 95.97% and 104.43%, and RSD was between 4.63% and 10.69%, respectively. This method was applied to determine the pharmacokinetic parameters. The main pharmacokinetic parameters of retinamido-ester after oral administration via gastric gavage of 2.5, 5, 10 mg x kg(-1) were as follows, T(1/2): (11.28 +/- 7.23), (8.90 +/- 3.82), (8.01 +/- 5.65) h; AUC(0-infinity): (103.41 +/- 61.46), (190.23 +/- 74.99), (421.66 +/- 229.20) ng x h x mL(-1); MRT: (6.31 +/- 0.75), (5.98 +/- 0.71), (6.18 +/- 0.97) h; CL/F: (30.10 +/- 13.67), (29.58 +/- 10.59), (31.18 +/- 17.51) L x h(-1) x kg(-1); Vd/F: (414.94 +/- 159.82), (356.16 +/- 139.85), (369.28 +/- 322.72) L x kg(-1), respectively.

Itraconazole in the treatment of superficial candidal infections: twelve years' clinical experience / 中国医学科学院学报

Itraconazole has been used to treat superficial candidal infections in China for 12 years with promising efficacy and safety. This article retrospectively reviewed literatures published in the mainstream journals in China with an attempt to find a reasonable therapy for Chinese populations.