title: Nanoemulsions for Intranasal Delivery of Riluzole to Improve Brain Bioavailability: Formulation Development and Pharmacokinetic Studies.
abstract: BACKGROUND
  Amyotrophic Lateral Sclerosis (ALS), a motor neuron disease (MND), is a progressive neurodegenerative disorder characterized by the deterioration of both upper and lower motor neurons. Only one drug (riluzole) has been approved for the treatment of ALS. Riluzole is a BCS class II drug having 60% absolute bioavailability. It is a substrate of P-glycoprotein and BBB restricts its entry in brain.
  
  
  OBJECTIVE
  This investigation was aimed to develop O/W nanoemulsion system of riluzole to improve its brain bioavailability.
  
  
  METHODS
  Riluzole loaded nanoemulsion was prepared by phase titration method. It was consisting of 3% w/w Sefsol 218, 28.3% w/w Tween 80:Carbitol (1:1) and 68.7% w/w water. It was characterized for drop size, drop size distribution, transmittance, viscosity, pH, zeta potential, conductivity and nasal ciliotoxicity study. Thermodynamic stability and room temperature stability of prepared nanoemulsion formulation were evaluated. Pharmacokinetic and brain uptake study was carried out using albino rats (wistar) post intranasal and oral administration.
  
  
  RESULTS
  Riluzole loaded nanoemulsion was having a drop size of 23.92±0.52 nm. It was free from nasal ciliotoxicity and stable for three months. Brain uptake of riluzole post intranasal administration of riluzole loaded nanoemulsion was significantly (P <4.10 × 10-6) higher when it was compared with oral administration of riluzole loaded nanoemulsion.
  
  
  CONCLUSIONS
  This study indicates that nanoemulsion of riluzole for intranasal administration could be a promising approach for the treatment of ALS to minimize the dose of riluzole in order to avoid dose related adverse events.
authors.affiliation: Ramanbhai Patel College of Pharmacy, Charotar University of Science and Technology, CHARUSAT Campus, Changa Anand - 388 421, Gujarat, India.
authors.forename: Rajesh H
authors.initials: RH
authors.lastname: Parikh
authors.forename: Ravish J
authors.initials: RJ
authors.lastname: Patel
mesh_terms: D000281:Administration, Intranasal; D000818:Animals; D001682:Biological Availability; D001921:Brain / Q000378:metabolism*; D002626:Chemistry, Pharmaceutical; D004355:Drug Stability; D004655:Emulsions; D008055:Lipids / Q000737:chemistry; D053758:Nanoparticles / Q000008:administration & dosage / Q000737:chemistry / Q000633:toxicity; D009297:Nasal Mucosa / Q000187:drug effects / Q000473:pathology; D018696:Neuroprotective Agents / Q000008:administration & dosage / Q000737:chemistry / Q000493:pharmacokinetics / Q000633:toxicity; D011108:Polymers / Q000737:chemistry; D017208:Rats, Wistar; D019782:Riluzole / Q000008:administration & dosage / Q000737:chemistry / Q000493:pharmacokinetics / Q000633:toxicity; D012995:Solubility; D013501:Surface-Active Agents / Q000737:chemistry; D014783:Viscosity
chemical_list: D004655:Emulsions; D008055:Lipids; D018696:Neuroprotective Agents; D011108:Polymers; D013501:Surface-Active Agents; D019782:Riluzole