Beyond Dysphagia in Parkinson's Disease: 3D Printing of Orally Disintegrating Tablets (ODTs) for Optimized Treatment

Parkinson's disease (PD) is frequently complicated by dysphagia, undermining timely and reliable oral dopaminergic medication. Levodopa's short half-life and delayed gastric emptying in advanced PD result in inconsistent absorption, delayed "ON" periods, and challenges to adherence. Orally disintegrating tablets (ODTs) dissolve without water and can mitigate swallowing limitations. Research indicates that selegiline ODT achieves a faster time to peak and higher relative bioavailability via partial buccal absorption, whereas carbidopa/levodopa ODTs are bioequivalent to immediate release tablets (with similar AUC/C_max and approximately 1 h T_max) without consistent motor advantages but with higher patient acceptability. This review synthesizes the clinical burden of dysphagia in PD, pharmacokinetic constraints of current formulations, and the reasons for ODTs. We highlight 3D printing as a route to personalized, dysphagia friendly therapy, which enables dose individualization, polypills, engineered disintegration or release, and point-of-care production. Feasibility studies underscore stability considerations such as carbidopa, throughput and regulatory requirements (QbD/GMP), and bioequivalence information. We outline priorities to integrate 3D printed ODTs into PD care, aligning formulation, pharmacokinetics, and human factors to improve adherence and clinical outcomes.