Voltammetric and RP-LC assay for the antidepressant drug mirtazapine: A validated method for the pharmaceutical dosage form

Abstract

In the present paper, rapid, sensitive, selective, accurate and precise analytical methodologies were developed for the determination of the antidepressant drug mirtazapine (MIR) using voltammetry and liquid chromatography. In cyclic voltammetry (CV), MIR showed one sharp oxidation peak and one additional wave in acidic media in the anodic direction; at pH 5.50, the mirtazapine peak was single and sharp. Under optimized conditions, the peak current showed a linear dependence with concentration in the range between 0.212 and 26.54 µg/mL for glassy carbon (GC) and 1.06 and 26.54 µg/mL for boron-doped diamond (BDD) electrodes using differential pulse (DP) and square wave (SW) voltammetric techniques. The possible oxidation mechanisms are also discussed. A simple and fully validated reverse phase-liquid chromatography (RP-LC) method to test for MIR in tablets was developed using an X-Select RP-18 column (250x4.60 mm ID x 5µm) at 25ºC with methanol:water (30:70, v/v, containing 15 mM o-phosphoric acid) as the mobile phase adjusted to pH 3.0. The RP-LC method allowed quantification over a MIR concentration range of 1.0-18.0 µg/mL. MIR was exposed to thermal, photolytic, or oxidative stress, as well as acid and base hydrolysis conditions, and the stressed samples were assayed by the proposed LC method. The proposed methods allow for a number of cost- and time-saving benefits.