Bioactive-Loaded Transdermal Drug Delivery Systems: A Promising Approach for Neurodegenerative Disease Therapy

Treatment of various neurodegenerative diseases like Parkinson's disease, Alzheimer's disease, and Huntington's disease have many challenges to global health due to their progressive nature and the limited efficacy of existing pharmacological agents. Conventional oral and parenteral delivery of med-ications like Rivastigmine, Rotigotine, selegiline, and cannabinoids helps in improving cognitive func-tion, motor symptoms, and behavioural problems but do notalways provide desired therapeutic re-sults, as they may undergo extensive first-pass metabolism, have varying plasma levels, and lack (Blood Brain Barrier) BBB penetration, leading to side effects during systemic administration. Hence, switching to natural based drug therapy is emerging as neuroprotective natural substances like Bacopa monneri, curcumin drug delivery system bypass first pass metabolism and reduce gastrointestinal ir-ritation and improved patient safety and tolerability. Resveratrol, Betulinic acid, when combined with various polymers like HPMC, PVA, chitosan, and Eudragit provides enhanced bioavailability and extended drug release when compared to oral forms. Transdermal drug delivery system (TDDS), par-ticularly the transdermal patches, can be a suitable approach for long-term treatment of neurodegen-erative diseases because of their advantages providing controlled and sustained drug delivery, in-creased bioavailability, reduced gastrointestinalside effects, and improving patientcompliance. Transdermal Patches of bioactive compounds produced as nanocarriers, microneedles are used to en-hance drug transport and achieve targeted delivery to the brain, and contributes to improvements. This review critically examines the effectiveness of synthetic medications and its limitation, transdermaldrug delivery of conventional drugs, and the bioactive based transdermal drug delivery systems. Nat-ural compound–based patches offer an effective, safer, and patient-friendly approach for managing neurodegenerative diseases.