In the present work the photodegradation products of five tricyclic antidepressants (amitriptyline hydrochloride, nortriptyline hydrochloride, imipramine hydrochloride, clomipramine hydrochloride and doxepine hydrochloride) were analyzed by thin-layer chromatography. We used aqueous solutions of 0,1% which were irradiated in UV light, and from which we took samples at well-determined periods of time (30, 60, 120, 240, 360, 480 minutes). These solutions were analyzed by thin-layer chromatographic methods according to the stipulations of the European Pharmacopoeia 6th Edition and also by an original method developed by us. During these procedures we managed the separation of the studied substances and of their photodegradation products as well. By comparing the chromatograms we established comparisons between the stability of the studied compounds.
Keywords: tricyclic antidepressants, photostability, degradation products, thin-layer chromathograph