Novel methods of antiepileptic drug delivery - polymer-based implants
Epilepsy is a neurological disorder characterised by spontaneous seizures. Over one third of patients receive insufficient benefit from oral anti-epileptic drug (AED) therapy, and continue to experience seizures whilst on medication. Epilepsy researchers are consequently seeking new ways to deliver AEDs directly to the seizure focus in the brain in order to deliver higher, more effective doses to the seizure focus whilst bypassing the remainder of the brain and body to prevent side effects. The focus of this review will be polymer-basedimplants, which are polymeric devices loaded with AED that are designed for implantation at the seizure focus in order to achieve gradual, continuous release of AED direct into the region of the brain responsible for seizures. Polymer-basedimplants produced for epilepsy to date are based on a range ofpolymers, both biodegradable and non-biodegradable, and range from simple materials development studies through to investigations ofimplants in animal models of seizures and epilepsy, with varying degrees of success. This review describes the range ofmethods employed to manufacture polymer-basedimplants and compares their advantages and potential appeal to industry, and describes and compares the results and successes ofpolymer-based materials and devices produced to date for the treatment of epilepsy. We also discuss disadvantages and hurdles to be overcome in the field, and describe our predictions for advances to be made in the field in the coming decade.