trans-Resveratrol (trans-RES) and cis-resveratrol are isomers that are difficult to separate due to their structural similarities. This study developed a method to enhance the solubility and stability of trans-RES, focusing on preventing its isomerization to the inactive cis form. A reversed-phase high-performance liquid chromatography (RP-HPLC) method was optimized for quantifying trans-RES complexed with hydroxypropyl-β-cyclodextrin (HPβCD) in stealth liposomes. The technique used an isocratic mobile phase of water:acetonitrile (65:35 v/v) at a flow rate of 1 mL/min, with UV detection at 306 nm. Validation showed excellent linearity (R2 = 0.9997), precision (RSD < 2%), accuracy (98–102% recovery), and sensitivity (LOD 0.96 μg/mL, LOQ 2.91 μg/mL), with high resolution (Rs > 16.5) between trans- and cis-isomers and robustness against minor parameter variations. The dual-delivery system combined HPβCD inclusion complexes with stealth liposomes. Liposomal formulations F1–F5 showed sustained trans-RES release over 24 h, with F5 complexed in HPβCD demonstrating the sustained release profile (49.8% at 12 h). Release kinetics followed the Korsmeyer–Peppas model (R2 > 0.90), indicating a non-Fickian mechanism. Furthermore, the formulation protected trans-RES from UV-induced isomerization, confirming enhanced stability. © 2025 The Authors. Published by American Chemical Society