title: Nanosized Drug Delivery Systems for Direct Nose to Brain Targeting: A Review.
abstract: BACKGROUND
  Drug targeting to brain has always been problematic due to Blood-Brain Barrier (BBB), which, does not allow most of the drugs to pass through it as they are hydrophilic and macromolecular drugs. So, in order to bypass the BBB, alternative modes of administration were searched and nasal to brain delivery route was tried by many workers. Such studies yielded patented nano-formulations with the ability to cross blood brain barrier.
  
  
  METHODS
  Nanoparticles being smaller in size and large surface area help in increasing the rate of drug permeation to the brain. In this review work, emphasis has been laid on discussion on various works done in the field of nasal delivery of drugs to brain over the last decade.
  
  
  RESULTS
  The works that are discussed in this paper show better drug targeting of brain when given through nasal route as nanoparticles. Experiments performed in animal models have clearly exhibited that nano-sized formulations are able to facilitate the delivery of drugs to brain through nose in comparison to tantamount drug solutions.
  
  
  CONCLUSIONS
  However, it is not yet confirmed whether the drug is freed from the formulation in the nasal cavity and then absorbed or the nanoparticles themselves are absorbed and then the drug is released in the CNS. Furthermore, the toxicity studies were not carried out extensively in suitably designed model, which should be considered before going for further studies and application.
authors.forename: Kunjan
authors.initials: K
authors.lastname: Phukan
authors.forename: Marika
authors.initials: M
authors.lastname: Nandy
authors.forename: Rupanjali B
authors.initials: RB
authors.lastname: Sharma
authors.affiliation: Department of Pharmaceutical Sciences, Dibrugarh University, Dibrugarh, Assam, India. hemantasharma123@yahoo.co.in.
authors.forename: Hemanta K
authors.initials: HK
authors.lastname: Sharma
mesh_terms: D000281:Administration, Intranasal; D000818:Animals; D001812:Blood-Brain Barrier / Q000378:metabolism*; D004337:Drug Carriers; D004339:Drug Compounding; D016503:Drug Delivery Systems / Q000379:methods*; D006801:Humans; D050997:Nanomedicine / Q000379:methods*; D053758:Nanoparticles; D065588:Nasal Absorption; D009297:Nasal Mucosa / Q000378:metabolism; D010539:Permeability; D004364:Pharmaceutical Preparations / Q000008:administration & dosage* / Q000737:chemistry / Q000378:metabolism; D011108:Polymers / Q000737:chemistry*; D013678:Technology, Pharmaceutical / Q000379:methods*
chemical_list: D004337:Drug Carriers; D004364:Pharmaceutical Preparations; D011108:Polymers