Determination of a potential antiasthmatic compound, tibenelast, and its application to phase I clinical trials.

A sensitive and selective high-performance liquid chromatographic (HPLC) assay was developed for the determination of tibenelast, 5,6-diethoxybenzo[b]thiophene-2- carboxylic acid, in plasma and urine. The plasma assay involves protein precipitation with 4% trichloroacetic acid, while the urine assay is an automated solid-phase extraction procedure that utilizes the Waters Millilab workstation. The analysis was achieved by reversed-phase HPLC with ultraviolet detection at 313 nm.

Single-dose and steady-state pharmacokinetics of tomoxetine in normal subjects.

A pharmacokinetic profile of tomoxetine, a selective norepinephrine uptake inhibitor, was developed in human volunteers following single and multiple oral administrations. Following the administration of a single 90-mg oral dose of tomoxetine to four normal volunteers, the plasma half-life was 4.3 +/- 0.

The effect of crystal size on the bioavailability of benoxaprofen: studies utilizing deuterium labeled drug.

A study of the effect of crystal size on the bioavailability of benoxaprofen, 2-[4-chlorophenyl]-alpha-methyl-5-benzoxazoleacetic acid, in man is reported. The technique utilized comparison of either the plasma concentrations or urine levels, resulting from administration of deuterium labeled (2H7) drug in solution coadministered with a test capsule formulation. Drug concentrations were determined by gas chromatography, and the ratio of labeled to unlabeled drug was obtained by gas chromatography mass spectrometry.

Pharmacology of cinoxacin in humans.

Cinoxacin was almost completely absorbed when given orally and was found to be approximately 60 to 70% protein bound. Peak serum concentrations were reached within 2 h, and detectable serum concentrations persisted up to 12 h after administration of 0.25-, 0.

Determination of propoxyphene and norpropoxyphene by chemical ionization mass fragmentography.

The kinetics of propoxyphene and its primary metabolite, norpropoxyphene, have been simultaneously re-evaluated in man by using gas-liquid chromatography/mass spectrometry, deuterium-labeled mass internal standards, and multiple ion monitoring. Plasma concentrations in 4 volunteers determined for as long as 240 hr after single oral doses of 2 propoxyphene salts indicate the overall half-life of propoxyphene to be 11.8 hr and of norpropoxyphene to be 36.