Drug delivery to brain by microparticulate systems.

The site specific delivery of chemotherapeutic agents allows maximum concentration of an agent at a desired body site. This area specific drug delivery decreases the unwanted systemic distribution and decreases toxicity of the administered drugs. Blood-Brain Barrier (BBB) is considered to be an obstacle in delivering large number of drugs to brain. The endothelial cells forming the tubular capillaries in the brain are cemented together by intercellular tight junctions. In this way, the BBB has an important role in providing a stable extracellular environment in the central nervous system. Lack of fenestrations, very few pinocytotic vesicles, and more mitochondria are other differences of the brain capillaries which play important role in transport of drugs to brain (Fig.1). The purpose of this paper is to summarise the methods for BBB permeability modifications and to focus on various examples in delivering drugs, especially neuroncology and neuroactive drugs, to brain by microparticulate systems.