Improved Stability-Indicating RP-UPLC Method for the Levamisole Hydrochloride Assay and Estimation of Its Related Compounds.

ABSTRACT

BACKGROUND: Levamisole hydrochloride (LVM) is an anthelmintic drug substance with immunomodulatory and anticancer activities. LVM has also found usage as a cutting agent in street cocaine. OBJECTIVE: This study was aimed to develop and validate an alternative and improved stability-indicating reversed-phase ultraperformance liquid chromatography (RP-UPLC) method for the determination of LVM and the estimation of its related compounds. METHOD: The UPLC method for the assay was optimized in terms of organic solvents consumed, pH, column temperature, and flow rate. Determination of LVM and its related compounds was performed using a gradient elution on a Waters ACQUITY UPLC® BEH C18 (50 mm × 2.1 mm i.d., 130 Å). The column temperature was maintained at 35°C. Mobile phase A was composed of aqueous 5 mM ammonium hydroxide, and mobile phase B was composed of acetonitrile. All the analytes were monitored by UV detection at 215 nm with a flow rate of 0.7 mL/min. The total runtime of the method with column equilibration is 4.0 min. RESULTS: The developed method met all the acceptance criteria of the current International Council for Harmonization [ICH Q2 (R1)] guidelines. The method was tested in terms of specificity, linearity (R2 > 0.999), limit of detection (LOD; 0.06 µg/mL), limit of quantitation (LOQ; 0.2 µg/mL), accuracy, precision, and robustness. With a short analysis time (<2.5 min) and reduced consumption of organic solvents, the proposed method is considered a greener alternative to conventional chromatographic methods. CONCLUSIONS: An alternative and improved UPLC method was successfully developed and validated in accordance with the ICH guidelines for the determination of LVM and the estimation of its related compounds. HIGHLIGHTS Due to its high degree of selectivity, speed, and accuracy, the developed method can significantly benefit the end-users with laboratory efficiency and throughput during routine analysis of production batches and stability monitoring of LVM-related drug products.