Speciation study of the anti-inflammatory drug tenoxicam (Htenox) with Cu(II): X-ray crystal structure of [Cu(tenox)2(py)2].EtOH

A speciation study was carried out in aqueous solution of the anti-inflammatory drug tenoxicam (Htenox), under quasi-physiological conditions (temperature of 37°C and ionic strenght 0.15 M NaCl) in order to determine the acidity constants from spectrophotometric studies. Subsequently, the spectrophotometrical speciation of the different complexes of Cu(II) with the drug was performed under the same conditions of temperature and ionic strength. The crystalline structure of the complex [Cu(tenox)2(py)2].EtOH was determined, revealing the coordination mode of the tenoxicam to the cation.