Absorption, Distribution, Metabolism, and Excretion of [14C]-Volixibat in Healthy Men: Phase 1 Open-Label Study.

BACKGROUND AND OBJECTIVES: Volixibat is a potent inhibitor of the apical sodium-dependent bile acid transporter in development for the treatment of nonalcoholic steatohepatitis. This phase 1, open-label study investigated the absorption, distribution, metabolism, and excretion of [14C]-volixibat in heathy men. METHODS: Eligible men (n = 8) aged 18-50 years (body mass index 18.0-30.0 kg/m2; weight >50 kg) received a single oral dose of [14C]-volixibat 50 mg containing ~5.95 µCi radioactivity. The primary objectives were to assess the pharmacokinetics of [14C]-volixibat and to determine the total radioactivity in whole blood, plasma, urine, and feces at pre-selected time points over 6 days. The secondary objectives were to characterize metabolites and to assess the safety and tolerability. RESULTS: Low concentrations of volixibat (range 0-0.179 ng/mL) were detected in plasma up to 8 h following administration; the pharmacokinetic parameters could not be calculated. No radioactivity was observed in plasma or whole blood. The percentage (mean ± standard deviation) of total radioactivity in urine was 0.01 ± 0.007%. The vast majority (92.3 ± 5.25%) of volixibat was recovered in feces (69.2 ± 33.1% within 24 h). Unchanged volixibat was the only radioactive component detected in feces. Adverse events were mild in severity and mostly gastrointestinal. Changes in laboratory values were not clinically meaningful. CONCLUSIONS: Following oral administration, [14C]-volixibat was excreted unchanged from the parent compound almost exclusively via fecal excretion, indicating that the drug is minimally absorbed. Consistent with other studies, adverse events were primarily gastrointestinal in nature. ClinicalTrials.gov identifier NCT02571192.

Novel LC-MS/MS method for simultaneous quantification of KW-7158, a new drug candidate for urinary incontinence and bladder hyperactivity, and its metabolites in rat plasma: a pharmacokinetic study in male and female rats.

To investigate the pharmacokinetics of KW-7158 (CAS 214763-95-8), a new drug candidate for urinary incontinence and bladder hyperactivity, in male and female rats, we developed and validated a simultaneous quantification method for KW-7158 and its 2 metabolites, M1 and M2, in plasma using high performance liquid chromatography-tandem mass spectrometry with positive/negative ion-switching scan mode. The method was selective and sensitive to KW-7158, M1 and M2 with overall precision expressed as coefficient of variance less than 11.8% and accuracy (relative error) within ± 13.7% in intra- and inter-assay variability. This method was used to determine the plasma concentration of KW-7158, M1 and M2 after intravenous and oral administration of KW-7158 in male and female rats. KW-7158 was detected as a primary constituent in plasma in both administration routes. M1 was a major metabolite with the concentration ratio of 10-20% of KW-7158, and M2 was a minor metabolite. Pharmacokinetics of KW-7158 after oral administration was considered to be linear at doses from 0.01 to 1 mg/kg. Bioavailability was relatively high with the values of 69.4 ± 17.1% and 82.6 ± 20.0% at a dose of 0.1 mg/kg in male and female rats, respectively. There was a little gender difference in pharmacokinetics of KW-7158 and its metabolites in rats.

[Dieldrin, aldrin, endrin, isodrin, endosulfan 1 and 2 on fish in the Gulf of Gdansk]. / Dieldryna, aldryna, endryna, izodryna, endosulfan 1 i 2 w rybach w Zatoce Gdanskiej.

The residues of dieldrin, aldrin, endrin, isodrin, endosulfan 1 and 2 has been determined in a several species of fish caught in the Gulf of Gdansk in 1992. The method of measurement was capillary gas chromatograph and low resolution mass spectrometry (HRGC/LRMS) after a nondestructive extraction and clean-up step with a further fractionation of the extract on Florisil column. Apart from dieldrin no other cyclodiene pesticides studied were found in fishes in detectable amounts, and for dieldrin concentrations ranged from 0.84 to 6.6 ng/g wet weight.

A one-step enzyme-linked immunosorbent assay for a novel osteoblast differentiation-promoting compound, TAK-778 in serum.

TAK-778, ((2R,4S)-(-)-N-[(4-diethoxyphosphorylmethyl)phenyl]- 1,2,4,5-tetrahydro-4-methyl-7,8-methylenedioxy-5-oxo-3-benzothiepin-2- carboxamide), is a novel osteoblast differentiation-promoting compound, and its sustained-release formulation is expected to be clinically used for the enhancement of fracture healing. To date, TAK-778 levels in serum have been measured using conventional reverse-phase HPLC with inferior sensitivity and time-consuming procedures. We have produced polyclonal antibodies against TAK-778 by using one of its derivatives coupled with a carrier protein, and developed a one-step ELISA for the determination of TAK-778 in serum. The antibodies had minimal cross-reactivities to the biologically inactive metabolites including the oxidized-form (0.36%) and the cleavaged-form (0.00083%). The competitive ELISA was accomplished within three hours with a detection limit of 0.5 ng/ml serum, and the coefficients of variations for samples ranging from 1 ng/ml to 80 ng/ml were 1.1-4.4% in an intra-assay and 3.1-9.6% in an inter-assay. The present ELISA is so rapid, sensitive and selective for TAK-778 that it could be conveniently used in a clinical field for the determination of many serum specimens.

High-performance liquid chromatographic assay of a new non-steroidal anti-inflammatory agent, 2-(10,11-dihydro-10-oxodibenzo[b,f]thiepin-2-yl)propionic acid, in human plasma and urine.

A high-performance liquid chromatographic method for the quantitation of a new anti-inflammatory agent, 2-(10,11-dihydro-10-oxodibenzo[b,f]thiepin-2-yl)propionic acid (CN-100; I), has been developed. The assay consists in extracting samples containing I and mefenamic acid, the internal standard, under acidic conditions and analysis by reversed-phase chromatography using ultraviolet detection at 330 nm. Preliminary plasma concentration-time and cumulative urinary excretion profiles from a healthy subject following oral administration of the tablet formulation are presented. This method is simple, sensitive and reproducible and is applicable to studies of the pharmacokinetic behaviour of I in humans.