Search

Background. Bismuth-containing quadruple therapy achieves higher eradication rate of Helicobacter pylori. High level of bismuth in blood may result in damage of many organs. Wei Bi Mei is a new bismuth-containing drug combining chemicals and Chinese medicine portions. The present research is to study the pharmacokinetics of bismuth to evaluate the safety and rational use of Wei Bi Mei granules. Material and Methods. Seven healthy Chinese adult subjects were enrolled in this research, which included a single-dose study and a multiple-dose study. Wei Bi Mei granules were administered orally to the subjects at corresponding time. Blood and urine were collected. All samples were analyzed by inductively coupled plasma mass spectrometry (ICP-MS). Results. For single-dose Wei Bi Mei granules administration, the mean time to peak concentration (tmax) of bismuth was 2.29 ± 0.76 h, and the mean peak concentration (Cmax) of bismuth was 0.85 ± 0.55 ng/mL. For multiple-dose Wei Bi Mei granules administration, the Cmax was 2.25 ± 1.18 ng/mL at day two, and the volume of distribution (Vd) was (22.97 ± 9.82) × 103 L. The urinary excretion of bismuth was the fastest during the first two days, with a mean excretion rate of 3.84 ± 1.23 ng/h. The bismuth concentration in urine was significantly reduced at day 16. Conclusion. Bismuth has a washout period of approximately two months. The concentration of bismuth in blood was far less than the "safe level." Thus, Wei Bi Mei is a highly safe therapeutic medicine, with a good clinical application value. Wei Bi Mei should be recommended more widely for use in bismuth-containing quadruple therapy for the treatment of Helicobacter pylori infection. [ABSTRACT FROM AUTHOR]

Polymeric micelles are effective drug-loading sites and often used to formulate poorly water-soluble agents. In the present study, the amphiphilic copolymer methoxy-capped poly(ethyleneglycol)-block-poly(Ɛ-caprolactone) (mPEG-b-PCL) was successfully developed for the delivery of 20( R )-dammarane-3β,12β,20,25-tetrol (25-OH-PPD), a natural anticancer product from Panax notoginseng . The 25-OH-PPD-loaded micelles were characterized by morphological observation and thermodynamic stability testing. The concentrations of 25-OH-PPD was determined by HPLC–MS/MS. The optimum MRM transition of 25-OH-PPD was selected at m / z 479.4.0 → 461.4. The chromatographic separation was achieved on a SB-C18 column (1.8 μm, 2.1 × 50 mm) with an optimized gradient mobile phase system. The extraction recoveries of plasma and various tissue homogenates were within the range of 81.1%–110.4% and the matrix effects ranged from 81.9% to 106.7%. The intra- and inter- day precision values (RSD%) were less than 12.0%, with accuracies ranging from 85.2% to 114.2%. In addition, 25-OH-PPD was found to be stable in different biological matrix after three freeze-thaw cycles, at room temperature and at −70 °C for 4 weeks. The pharmacokinetics of 25-OH-PPD-loaded micelles was evaluated in rats. The micelles appeared as transparent liquid, stable and uniform spheres with an average particle size of 35.4 ± 4.2 nm. The maximum concentration of 25-OH-PPD in micelles was much lower than in free drug preparation. However, the drug in the micelles was released steadily, with a t 1/2 of 9.1 ± 4.0 h, significantly longer than in free drug (3.3 ± 1.4 h). However, the drug concentrations in tissues after the micelle administration were lower than the levels after administration of the free drugs. In summary, the micelles were characterized by long circulation and sustained release, with an ability to avoid uptake by the reticuloendothelial system, providing a promising approach to deliver intravenous 25-OH-PPD for therapy. [ABSTRACT FROM AUTHOR]

Objectives: The primary objective of this pilot study was to investigate whether the therapeutic drug monitoring of imipenem could be performed with spent effluent instead of blood sampling collected from critically ill patients under continuous renal replacement therapy. Methods: A prospective open-label study was conducted in a real clinical setting. Both blood and effluent samples were collected pairwise before imipenem administration and 0.5, 1, 1.5, 2, 3, 4, 6, and 8 h after imipenem administration. Plasma and effluent imipenem concentrations were determined by reversed-phase high-performance liquid chromatography with ultraviolet detection. Pharmacokinetic and pharmacodynamic parameters of blood and effluent samples were calculated. Results: Eighty-three paired plasma and effluent samples were obtained from 10 patients. The Pearson correlation coefficient of the imipenem concentrations in plasma and effluent was 0.950 (P<0.0001). The average plasma-to-effluent imipenem concentration ratio was 1.044 (95% confidence interval, 0.975 to 1.114) with Bland-Altman analysis. No statistically significant difference was found in the pharmacokinetic and pharmacodynamic parameters tested in paired plasma and effluent samples with Wilcoxon test. Conclusion: Spent effluent of continuous renal replacement therapy could be used for therapeutic drug monitoring of imipenem instead of blood sampling in critically ill patients. [ABSTRACT FROM AUTHOR]

Necrostatin-1 (Nec-1) is known as a specific and potent inhibitor of non-apoptotic cell death. In this study, a rapid and sensitive LC–MS/MS method that was developed for the determination of Nec-1 levels in plasma. Meanwhile, it has been used to explore pharmacokinetics and bioavailability of Nec-1 among rats. The m / z 260.1 → 131 was selected as the optimal MRM transition in analyzing Nce-1. The chromatographic separation was performed with SB-C18 analytical column using the optimized gradient elution mode. The extraction recoveries of Nec-1 ranged from 85.40% to 98.25% and the matrix effects were between 94.73% and 99.26%. Both the intra- and inter-day precision did not exceed 10.0%, respectively. Moreover, it is found that Nec-1 remained stable in plasma despite different processing and storage environment. The plasma concentration of Nec-1 was successfully determined among rats who received single dose via intravenous and oral route (5 mg/kg), respectively. A two-compartment model was fitted the concentration-time profile of the Nec-1 with C max 1733 μg L −1 and t 1/2 1.8 h for intravenous route, and C max 648 μg L −1 and t 1/2 1.2 h for oral route, respectively. The results showed that absolute bioavailability of Nec-1 was 54.8%. It is promising that the study is helpful to understand in vivo behaviors of Nec-1 and facilitate the future investigations of the compound. [ABSTRACT FROM AUTHOR]