A SEPARATION STUDY OF TRICYCLIC ANTIDEPRESSANT DRUGS BY HPLC WITH BETA-CYCLODEXTRIN-BONDED STATIONARY-PHASE

A systematic study of the separation of a series of tricyclic antidepr essant drugs (amitriptyline, nortriptyline, protriptyline, maprotiline , imipramine, chloripramine, doxepin-E and doxepin-Z) using reversed p hase HPLC with beta-cyclodextrin (beta-CD) bonded stationary phase is presented. The effect of the organic modifier (methanol) content and p H value of the aqueous phase of the mobile phase on retention was exam ined and experimental equations of these dependences were derived.The separation is mainly due to the variations of the strength of the CD-s olute complexes and this was proved by the good relationship found exp erimentally between corrected logk' (referred to pure aqueous mobile p hase) and the log of complex formation constants. Using the chromatogr aphic response function optimization procedure a mobile phase of 50/50 methanol/buffer pH 6.5 was found as optimum for separations of analyt ical use. The elution order of the solutes was tried to be correlated to various structure differences.