The impact of rifampicin on the pharmacokinetics of fuzuloparib in healthy Chinese male volunteers.

AIMS: This clinical study was conducted to evaluate the impact of rifampicin on the pharmacokinetics of fuzuloparib. METHODS: In this single-centre, single-arm, open-label, fixed-sequence study, healthy male subjects took a single 50 mg dose of fuzuloparib on two separate occasions: the first was on Day 1 as monotherapy, and the second was on Day 12 after oral administration of rifampicin 600 mg once daily for 8 days. Series of blood samples were obtained before and after fuzuloparib administration at different time points: pre-dose, and 0.5, 1, 2, 3, 4, 6, 8, 10, 12, 24, 36, 48 and 72 hours post-dose. All samples were examined using liquid chromatography with tandem mass spectrometry. PK parameters were estimated by using a non-compartmental method with Phoenix WinNonlin software. Safety was assessed by monitoring for changes in vital signs and laboratory tests, physical examinations, and incidences of adverse events (AEs). RESULTS: A total of 16 Chinese male subjects were enrolled. Of these, 16 and 15 cases were evaluable for PK analysis following administration with fuzuloparib alone and pretreatment with rifampicin, respectively. Pretreatment with rifampicin resulted in a statistically significant reduction in the systemic exposure to fuzuloparib. The treatment ratio and 90% confidence intervals (CIs) for AUC0-∞ and Cmax were 0.10 (0.095-0.115) and 0.32 (0.281-0.365), respectively. A single administration of fuzuloparib after multiple oral dosing of rifampicin was well-tolerated, without severe AEs. CONCLUSION: The exposure of fuzuloparib was dramatically decreased when pretreated with rifampicin. Strong CYP3A4 inducers should be avoided during fuzuloparib treatment.

Headspace solid-phase microextraction with on-fiber derivatization for the determination of aldehydes in algae by gas chromatography-mass spectrometry.

A simple, fast, sensitive and cost-effective method based on headspace solid-phase microextraction (HS-SPME) with on-fiber derivatization coupled with gas chromatography-mass spectrometry was developed for the determination of six typical aldehydes, 2E-hexenal, heptanal, 2E-heptenal, 2E,4E-heptadienal, 2E-decenal and 2E,4E-decadienal in laboratory algae cultures. As derivatization reagent, O-2,3,4,5,6-(pentafluorobenzyl) hydroxylamine hydrochloride, was loaded onto the poly(dimethylsiloxane)/divinylbenzene fiber for aldehydes on-fiber derivatization prior to HS-SPME. Various influence factors of extraction efficiency were systematically investigated. Under optimized extraction conditions, excellent method performances for all the six aldehydes were attained, such as satisfactory extraction recoveries ranging from 67.1 to 117%, with the precision (relative standard deviation) within 5.3-11.1%, and low detection limits in the range of 0.026-0.044 µg/L. The validated method was successfully applied for the analysis of the aldehydes in two diatoms (Skeletonema costatum and Chaetoceros muelleri), two pyrrophytas (Prorocentrum micans and Scrippsiella trochoidea) and Calanus sinicus eggs (feeding on the two diatoms above).