Physicochemical Characterization and In Vivo Evaluation of Taste-Masked Dextromethorphan Hydrobromide Resinates in Orally Disintegrating Tablets for Antitussive Action

Abstract

Dextromethorphan Hydrobromide (DMH), a widely used centrally acting antitussive, suffers from intense bitterness that limits patient compliance, particularly among paediatric, geriatric, and dysphagic populations. This study aimed to develop taste-masked orally disintegrating tablets (ODTs) of DMH using Carbomer (Carbopol 974P), a non-traditional ion-exchange polymer. Drug–resin complexes (DRCs) were prepared at different drug-to-resin ratios and optimized at 1:1. The complex was characterized by FTIR, DSC, and XRPD to confirm molecular interaction, loss of crystallinity, and structural stability. In vitro taste-masking assessment in simulated salivary conditions (pH 6.8, 5 mL) demonstrated minimal drug release (<0.50% in 120 s), confirming effective masking. The optimized DRC was compressed into ODTs (F1–F7), and formulation F7 exhibited the best physicochemical profile, including rapid disintegration (≤20 s) and 96.0 ± 3.45 % dissolution in 20 minutes. A trained human taste panel reported the DRC and ODTs as tasteless compared to pure drug and marketed tablets. In vivo bioequivalence studies in Wistar rats revealed improved pharmacokinetics for the test formulation, with higher Cmax, AUC, and shorter Tmax relative to the marketed product. The findings confirm Carbopol-based ion-exchange complexation as an effective approach for taste masking and enhanced bioavailability of DMH in ODT formulations.