Pharmaceutical Formulations and Analytical Methods of Donepezil

Donepezil is a selective acetylcholinesterase inhibitor widely prescribed for the symptomatic treatment of Alzheimer's disease. As therapeutic needs grow and delivery systems evolve, ensuring product quality, efficacy, safety and patient compliance becomes increasingly important. Meanwhile, pharmaceutical formulation innovations can improve clinical outcomes and usability, and analytical methods help ensure accurate assessment of drug behavior and quality control. This narrative review first provides a concise overview of donepezil's physicochemical properties and synthesis, then focuses on two interrelated domains: (i) pharmaceutical formulations and (ii) analytical methodologies. The former highlights advancements in novel delivery systems-such as liposomes, nanoparticles, microneedles, nasal gels, and long-acting injectable depots-developed to enhance brain targeting, prolong drug release, and reduce systemic side effects. The latter reviews validated analytical methods for quantifying and characterizing donepezil in pharmaceutical and biological matrices, with emphasis on RP-HPLC, LC-MS/MS, chiral separations, and emerging electrochemical and spectroscopic techniques. These analytical strategies are essential for evaluating formulation performance, monitoring drug stability, and ensuring regulatory compliance. Collectively, this review underscores that progress in both formulation design and analytical science is vital to optimizing donepezil-based therapies for Alzheimer's disease management.