Development and validation of a method for the analysis of hydroxyzine hydrochloride in extracellular solution used in in vitro preclinical safety studies

[Display omitted] •A UPLC–MS/MS method for Hydroxizine HCl in hERG assay solution was developed.•The method was successfully validated for accuracy, repeatability and stability.•Quantification of low concentrations in salt matrix was performed.•Sensitivity increased significantly by dilution with mobile phase (LOQ 0.09ng/ml). In the process of drug development, preclinical safety studies are to be performed that require the analysis of the compound at very low concentrations with high demands on the performance of the analytical methods. In the current study, a UPLC–MS/MS method was developed and validated to quantify hydroxyzine hydrochloride in an extracellular solution used in a hERG assay in concentrations ranging from 0.01 to 10μM (4.5ng/ml–4.5μg/ml). Chromatographic separation was achieved isocratically on an Acquity BEH C18 analytical column. The assay was validated at concentrations of 0.11–1.1ng/ml in end solution for hydroxyzine hydrochloride. Linearity was demonstrated over the range of concentrations of 0.06–0.17ng/ml and over the range of concentrations of 0.6–1.7ng/ml in end solution with the coefficient of correlation r>0.99. Accuracy of the achieved concentration, intra-run, and inter-run precision of the method were well within the acceptance criteria (being mean recovery of 80–120% and relative standard deviation ≤10.0%). The limit of quantification in extracellular solution was 0.09ng/ml. Hydroxyzine hydrochloride in extracellular solution proved to be stable when stored in the fridge at 4–8°C for at least 37 days, at room temperature for at least 16 days and at +35°C for at least 16 days. The analytical method was successfully applied in hERG assay.