POLAROGRAPHIC-DETERMINATION OF DOXEPIN HYDROCHLORIDE

Doxepin - NN-dimethylbenz[b,e]oxepin-DELTA11(6H),gamma-propylamine hydrochloride (syn. Sinequan) is a tricyclic antidepressant which acts and is used similarly to amitryptyline. Also like amitryptyline it has marked sedative properties. The effective therapeutic concentration in blood is 30-150 mug ml-1. Until now doxepin was determined by titration in non-aqueous medium [BP 1988], spectrophotometrically and by gas chromatography [USP XXII]. For the determination of doxepin and some of its metabolites in body fluids colorimetry, spectrofluorimetry [1] and gas chromatography were used [2,3]. The producer suggests a spectrophotometric method for determination of doxepin in capsules. There are no data in the literature concerning electrochemical properties of doxepin. The main purpose of this work was to investigate polarographic behaviour of doxepin and to elaborate a simple and rapid method of its determination in pure substance and in capsules.