Development and Validation of a Stability Indicating RP-UPLC Method for Analysis of Imipramine Hydrochloride in Pharmaceuticals

The objective of the current study was the development of a simple, rapid, and accurate isocratic reverse-phase ultra-performance liquid chromatographic (RP-UPLC) method for the routine control analysis of imipramine hydrochloride (IMH) in bulk drug and in pharmaceutical formulations. This work was carried out in order to reduce analysis time and maintaining good efficiency which in turn is focused on high-speed chromatographic separations. The method was developed using Waters Acquity BEH C18 column (100？mm × 2.1？mm, 1.7？μm) with mobile phase consisting of a mixture of acetonitrile and ammonium acetate buffer of pH-5 (80？:？20, v/v/v). UV detection was performed at 220？nm for eluted compound. An excellent linearity was observed in the concentration range 0.2–3？μg/mL IMH with a regression coefficient ( ) value of 0.9999. The method developed was validated and forced degradation was performed as per ICH guidelines. The limit of detection ( ) was 0.2532？ng/mL and the limit of quantitation ( ) was found to be 0.7672？ng/mL. The drug IMH was subjected to hydrolytic, acidic, basic, thermal, photolytic, and oxidative stress conditions according to ICH regulations. IMH was found to be stable in basic, thermal, and photolytic conditions and degrades in acidic, hydrolytic, and oxidative stress conditions. 1. Introduction Imipramine hydrochloride (IMH) is a tricyclic antidepressant. It is a dibenzazepine derivative and chemically IMH is 3-(10,11-Dihydro-5H-dibenz[b,f]azepin-5-yl) propyldimethylamine hydrochloride (Figure 1). IMH is commonly used to treat the depressive disorders owing to their efficiency in elevating the mood of patients by interfering to the reuptake of norepinephrine or serotonin [1]. The drug is official in European Pharmacopoeia [2]. Figure 1: Structure of imipramine hydrochloride. The literature on the methods for the determination of IMH is vast. Several analytical methods have been reported for the determination of IMH in biological fluids and/or pharmaceutical formulations. These include chromatographic techniques like HPLC [3–9], TLC [10], GC [11–14], LC with direct injection and electrochemical detection [15], adsorptive stripping voltammetry [16], chemometric methods [17], flow-injection extraction spectrophotometry [18], derivative spectrophotometry [19, 20], and visible spectrophotometry [20–24]. Many of the reported methods for the determination of imipramine suffer from one or the other disadvantages like time consuming and require expensive experimental setup [11–14], and chemometric methods are less sensitive [17]. Besides, the