While there is currently no cure for PD, there are medications that can help to manage the symptoms. However, these medications can have limitations, such short-lived effects and difficulty crossing the blood-brain barrier. The blood-brain barrier is a highly selective barrier that protects the brain from harmful substances in the bloodstream. Unfortunately, it also prevents many drugs from reaching the brain, where they are needed to treat PD. Drug delivery systems are being developed to overcome these limitations. Drug delivery systems are designed to deliver drugs to specific sites in the body, including the brain. For PD, drug delivery systems are being investigated as a way to (i) improve the delivery of drugs to the brain; (ii) reduce harmful side effects; (iii) provide sustained release of medication.