Spectrofluorimetric assay for the photodegradation products of alprazolam

A new spectrofluorimetric assay for the photodegradation products of the ansiolytic drug alprazolam is described. Alprazolam was found to be highly photolabile and special care should be taken to avoid light exposure during alprazolam storage and handling. The photostability of alprazolam was evaluated at pH 2.0, 3.6 and 5.0. The drug was exposed to UVA-UVB radiations, the photodegradation of alprazolam was followed by high-performance liquid chromatographic (HPLC) and the developed spectrofluorimetric assay allowed determination of the photodegradation products at very low concentrations (> or = 10(-5) M). The photoinstability was found to increase with the pH value decreasing, consequently acidic media should be avoided during the drug-development process.