title: Pharmacokinetics of fluralaner in dogs following a single oral or intravenous administration.
abstract: BACKGROUND
  Fluralaner is a novel systemic insecticide and acaricide. The purpose of these studies was to investigate the pharmacokinetic properties of fluralaner in Beagle dogs following single oral or intravenous (i.v.) administration.
  
  
  METHODS
  Following the oral administration of 12.5, 25 or 50 mg fluralaner/kg body weight (BW), formulated as chewable tablets or i.v. administration of 12.5 mg fluralaner/kg BW, formulated as i.v. solution to 24 Beagles, plasma samples were collected until 112 days after treatment. Plasma concentrations of fluralaner were measured using HPLC-MS/MS. Pharmacokinetic parameters were calculated by non-compartmental methods.
  
  
  RESULTS
  After oral administration, maximum plasma concentrations (C(max)) were reached within 1 day on average. Fluralaner was quantifiable in plasma for up to 112 days after single oral and i.v. treatment. The apparent half-life of fluralaner was 12-15 days and the mean residence time was 15-20 days. The apparent volume of distribution of fluralaner was 3.1 L/kg, and clearance was 0.14 L/kg/day.
  
  
  CONCLUSIONS
  Fluralaner is readily absorbed after single-dose oral administration, and has a long elimination half-life, long mean residence time, relatively high apparent volume of distribution, and low clearance. These pharmacokinetic characteristics help to explain the prolonged activity of fluralaner against fleas and ticks on dogs after a single oral dose.
authors.affiliation: MSD Animal Health Innovation GmbH, Zur Propstei, 55270 Schwabenheim, Germany. susanne.kilp@msd.de.
authors.forename: Susanne
authors.initials: S
authors.lastname: Kilp
authors.forename: Diana
authors.initials: D
authors.lastname: Ramirez
authors.forename: Mark J
authors.initials: MJ
authors.lastname: Allan
authors.forename: Rainer K A
authors.initials: RK
authors.lastname: Roepke
authors.forename: Martin C
authors.initials: MC
authors.lastname: Nuernberger
mesh_terms: D056810:Acaricides / Q000008:administration & dosage / Q000097:blood / Q000493:pharmacokinetics; D061605:Administration, Intravenous; D000284:Administration, Oral; D000818:Animals; D000977:Antiparasitic Agents / Q000008:administration & dosage / Q000097:blood / Q000493:pharmacokinetics*; D004285:Dogs / Q000378:metabolism*; D004305:Dose-Response Relationship, Drug; D005260:Female; D006207:Half-Life; D007306:Insecticides / Q000008:administration & dosage / Q000097:blood / Q000493:pharmacokinetics; D007555:Isoxazoles / Q000008:administration & dosage / Q000097:blood / Q000493:pharmacokinetics*; D008297:Male; D019999:Pharmaceutical Solutions; D012449:Safety; D013607:Tablets
chemical_list: C000591860:A1443 compound; D056810:Acaricides; D000977:Antiparasitic Agents; D007306:Insecticides; D007555:Isoxazoles; D019999:Pharmaceutical Solutions; D013607:Tablets