Comprehensive Bioequivalence Evaluation of Budesonide Using LC-MS/MS: Analytical Validation and Pharmacokinetic Insights

Background and Aim: Budesonide, a widely used corticosteroid, requires bioequivalence studies to confirm therapeutic interchangeability between generic and reference formulations. This study aimed to validate the analytical methods and assess the pharmacokinetics and bioequivalence of budesonide formulations in healthy volunteers. Methods: An open-label, randomized, two-period crossover study was conducted. Human plasma samples were analyzed using a validated LC-MS/MS method with dexamethasone as the internal standard. Calibration curves were linear over a concentration range of ۱۰۰–۴۰۰۰ ppt, ensuring high specificity, accuracy, and precision. Pharmacokinetic parameters, including Cmax, Tmax, AUClast, and AUCINF_obs, were calculated. Bioequivalence was determined by comparing the geometric mean ratios (GMRs) within the standard regulatory limits of ۸۰–۱۲۵%. Results: The LC-MS/MS method demonstrated excellent linearity (R² > ۰.۹۹) and precision (%RSD < ۵%). The test formulation achieved comparable pharmacokinetic profiles to the reference, with GMRs for AUClast and Cmax of ۱۰۱.۸۹% and ۱۰۴.۶۵%, respectively. The ۹۰% confidence intervals for all parameters were within the acceptable range, indicating bioequivalence.