Current trends in the application of nanoparticles in drug delivery

The discovery of new biologically active compounds that can be exploited therapeutically to treat disease has stalled, with fewer new drugs entering the market every year. The spotlight has now turned onto nanoparticles (NPs) as a versatile and multifaceted platform for the delivery of drugs. NPs offer better pharmacokinetic properties, controlled and sustained release, and targeting of specific cells, tissues or organs. All these features can improve the efficacy of existing drugs. The use of NPs can dramatically impact the treatment of many diseases. Many potential therapeutics that exist for alleviating brain diseases such as epilepsy, Alzheimer's disease and tumours are not feasible due to a lack of means to deliver drugs across the blood brain barrier. NPs offer an alternative solution, since they can be modified to cross the blood brain barrier. Additionally, NPs can also play a part in alternative methods of non-parental administration of drugs e.g. pulmonary and transdermally. Through active targeting and the enhanced permeation and retention effect, NPs reduce the systemic toxicity of chemotherapeutic drugs by ensuring delivery only to the site of the tumour, thus enhancing cancer treatment. We critically review the literature to provide a summary of current synthesis methodologies and applications of NPs in drug delivery.