Analytical Validation and Bioequivalence Assessment of Desloratadine in Human Plasma Using LC -MS/MS

Desloratadine, a widely prescribed antihistamine, faces challenges in ensuring consistent bioavailability and therapeutic efficacy across generic formulations. Accurate and validated analytical methods are crucial for addressing discrepancies in pharmacokinetic evaluations. Therefore, the aim of this study is to develop and validate a reliable LC -MS/MS method for quantifying desloratadine in human plasma and to assess its bioequivalence between generic and branded formulations. In this article, the authors employ a quadrupole mass spectrometer equipped with an electrospray ionization source and a Zorbax SB -C۱۸ column for chromatographic separation. A gradient mobile phase comprising formic acid in water and methanol was optimized for high sensitivity and reproducibility. Analytical method validation was conducted following ICH M۱۰ and EMEA guidelines, covering specificity, carry -over, linearity, accuracy, precision, matrix effect, and stability testing. Bioequivalence studies were conducted in human volunteers over a ۷۲-hour sampling period, and pharmacokinetic parameters were analyzed. The validated method demonstrated high sensitivity with an LLOQ of ۱۲۵ ppt, excellent linearity across a range of ۱۲۵–۸۰۰۰ ppt, and compliance with regulatory thresholds for accuracy and precision. Matrix effects and stability assessments further confirmed the method’s robustness. The bioequivalence study established comparable pharmacokinetic profiles between the tested formulations, supporting therapeutic interchangeability.