Valutazione del comportamento metabolico del tepoxalin dopo singola somministrazione orale nel cavallo

Tepoxalin is a veterinary drug registered for use in the dog as a dual inhibitor (cyclooxygenase - 5 lipoxygenase). In the horse, it seems mainly to trigger a strong cyclooxygenase inhibition because of its primary metabolite (RWJ-20142). The identification of its metabolic pathway is pivotal to understand better its clinical activity. A suitable HPLC method has been applied to LC-MS for the characterization of the main metabolites in plasma of horses orally treated with tepoxalin. Actually, experiments by mass spectrometry in full scan, product ion scan and precursor ion scan modes, provided information which enabled researchers to hypothesize the structure of a large part of the unknown metabolites detected, whose structure is strictly related to that of tepoxalin. One of these was speculated to be a structural isomer of the parental drug. These findings could be important to understand the pharmacology of tepoxalin in horses as well as to pave the way for new research on this drug.