**3. Nanopharmaceuticals: an approach to achieve brain targeting**

Brain targeting is potentially difficult because of multiple barriers. Recent advances in nanotechnology present opportunities to overcome such limitations and to deliver the drug to the brain targets. Nanopharmaceuticals are the relatively newer field that employed "therapeutic containing nanomaterial" with unique physicochemical properties due to their small size (one to several 100 nm), high


*SC, subcutaneous; IM, intramuscular; IV, intravenous; AHDH, attention deficit hyperactivity disorder; IFN, interferon; DSPE, distearoylphosphatidylethanolamine; EPC, egg phosphatidylcholine; PEG, polyethylene glycol.*
