title: Relative bioavailability of different buprenorphine formulations under chronic dosing conditions.
abstract: BACKGROUND
  Buprenorphine is an approved medication for the treatment of opioid dependence. Three sublingual formulations have been used at various times during its development-a solution containing alcohol, tablets containing buprenorphine alone, and tablets containing buprenorphine plus naloxone. This study compared the relative buprenorphine bioavailability of these different formulations.
  
  
  METHODS
  Outpatient volunteers (N = 10) were maintained for 14 days of daily administration on each formulation; the dose of buprenorphine (8 mg) was constant across formulations. Blood samples were collected and tested for buprenorphine and norbuprenorphine concentrations after 7 and 14 days maintenance on each formulation. Serial samples were collected before and for 6 h after a daily dose of each formulation.
  
  
  RESULTS
  Peak buprenorphine concentrations (C(max)) and area under the curve (AUC) for the 6h interval (AUC(0-6)) were highest for the solution and lowest for buprenorphine alone tablets; values for combination tablets were more similar to those for solution. Differences between formulations were less pronounced at day 14 than day 7. There was considerable between-subject variability in concentrations produced.
  
  
  CONCLUSIONS
  These results suggest there may be greater bioavailability of buprenorphine/naloxone versus buprenorphine alone tablets, and that the bioavailability of buprenorphine from the former is very similar to that seen with solution after 2 weeks of stabilization on each formulation.
authors.affiliation: Department of Psychiatry and Behavioral Sciences, Johns Hopkins University School of Medicine, 5510 Nathan Shock Drive, Baltimore, MD 21224, USA. ecsgss@aol.com
authors.forename: Eric C
authors.initials: EC
authors.lastname: Strain
authors.forename: David E
authors.initials: DE
authors.lastname: Moody
authors.forename: Kenneth B
authors.initials: KB
authors.lastname: Stoller
authors.forename: Sharon L
authors.initials: SL
authors.lastname: Walsh
authors.forename: George E
authors.initials: GE
authors.lastname: Bigelow
mesh_terms: D019540:Area Under Curve; D001682:Biological Availability; D002047:Buprenorphine / Q000008:administration & dosage* / Q000031:analogs & derivatives* / Q000097:blood*; D002626:Chemistry, Pharmaceutical; D005260:Female; D006801:Humans; D008297:Male; D009293:Opioid-Related Disorders / Q000097:blood* / Q000188:drug therapy*
chemical_list: D002047:Buprenorphine; C043585:norbuprenorphine