A. Phani kumar

The worldwide CNS pathology incidence displayed that about 1.5 billion people suffer from CNS disorders. The worrying  fact that , delivering drugs to the CNS is impaired by the presence of the blood-brain barrier (BBB) that represents the main obstacle for CNS drug development, many hydrophilic drugs and neuropeptides etc are may have difficulty in crossing the blood-brain barrier. It is important to consider not only the net delivery of the agent to the CNS, but also the ability of the agent to access the relevant target site within the CNS. Many strategies have been developed to deliver the drug into brain by crossing the BBB are chemical delivery systems, magnetic drug targeting, or drug carrier systems such as antibodies, liposomes or Nanoparticles. Among those, Nanoparticles have got a great concentration as the potential targeted drug delivery systems in the brain recently. Nanoparticles (NP) are solid colloidal particles ranging in size from one to 1000nm that may be utilized as brain drug delivery carriers. Coating of Nanoparticles with drug molecules are as carriers to cross the BBB and transport the drugs to the specific sites in brain where they are needed.  NPs may provide slow drug release in blood and thereby reduces the peripheral toxicity. Key words: BBB, Drug delivery to brain, Nanotechnology, Colloidal drug carriers.