Comparative in vitro metabolism of 14C-ciclesonide in hepatocytes from the mouse, rat, rabbit, dog, and human.

The in vitro metabolism of ciclesonide, a novel inhaled nonhalogenated glucocorticoid for the treatment of asthma, was compared in cryopreserved hepatocytes from mice, rats, rabbits, dogs, and humans. Incubations of C-ciclesonide with individual hepatocyte suspensions revealed similar metabolite profiles in all 5 in vitro systems used. Ciclesonide was rapidly converted to its active metabolite, desisobutyryl-ciclesonide (des-CIC).

Determination of flunixin in edible bovine tissues using liquid chromatography coupled with tandem mass spectrometry.

An accurate, reliable, and reproducible assay was developed and validated to determine flunixin in bovine liver, kidney, muscle, and fat. The overall recovery and percent coefficient of variation (%CV) of twenty-eight determinations in each tissue for flunixin free acid were 85.9% (5.

Determination and confirmation of 5-hydroxyflunixin in raw bovine milk using liquid chromatography tandem mass spectrometry.

A method was developed and validated to determine 5-hydroxyflunixin in raw bovine milk using liquid chromatography tandem mass spectrometry (LC/MS/MS). The mean recovery and percentage coefficient of variation (%CV) of 35 determinations for 5-hydroxyflunixin was 101% (5% CV). The theoretical limit of detection was 0.