FLUORIGENIC DERIVATIZATION OF OXAZEPAM - APPLICATION TO ITS DETERMINATION IN PHARMACEUTICALS

Oxazepam, when heated in mixtures of acetic acid and methanol, undergoes a reaction giving an intense fluorescence at excitation and emission wavelengths of 364 and 469 nm, respectively. The best reaction conditions were a 7:25 methanol:acetic acid volume ratio, a temperature of 100 degrees C (examinated range 50-100 degrees C), and a reaction time of 5 minutes. A linear range from 0.025 to 50 mu g/ml with a limit of detection of 0.014 mu g/ml and a reproducibility within day of less than 5% were attained. A Flow Injection Analysis method was designed and a linear range from 0.1 to 100 mu g/ml with a limit of detection of 0.035 mu g/ml and a reproducibility within day of less than 5% were obtained. These methods were applied to the determination of oxazepam in five pharmaceutical formulations.