ABSTRACT
A study on absorption and elimination in the urine of 2-(4-isobutylphenyl)-propiohydroxamic acid (ibuproxam, Ibudros) (400 mg film tablets) after administration to healthy volunteers is reported. In the plasma, only a minimum concentration of ibuproxam as such could be found: instead its chief metabolite ibuprofen mainly present, with top peaks at 45 min. The maximum ibuprofen concentration in the plasma--when obtained through metabolization of ibuproxam--is significantly higher than after administration of an equal dose of ibuprofen. This phenomenon is related to the chemico-physical characteristics of the two compounds.
Subject(s)
Anti-Inflammatory Agents/metabolism , Benzeneacetamides , Hydroxamic Acids/metabolism , Adult , Anti-Inflammatory Agents/adverse effects , Biological Availability , Chemical Phenomena , Chemistry, Physical , Female , Humans , Intestinal Absorption , Kinetics , Male , SolubilityABSTRACT
The metabolism of 2-(4-isobutylphenyl)-propio-hydroxamic acid (ibuproxam, Ibudros), a new molecule with anti-inflammatory, antipyretic and analgesic activity was studied by its administration orally and rectally to the rat. The analysis, carried out with gas chromatographic method and thin-layer chromatography, showed that the drug is present in blood as 2-(4-isobutylphenyl)-propionic acid (ibuprofen), an anti-inflammatory drug which is commonly used and the metabolites of which are already known. Using the same methods, it was observed that only a few traces of the hydroxamic acid appear in the urines of rats treated with ibuproxam, whilst the ibuprofen metabolite is absent. Therefore, we conclude that the drug ibuproxam changes rapidly into ibuprofen, following afterwards the same known metabolic process as the latter drug.