title: Pharmacokinetic comparison and bioequivalence evaluation of two 10-mg baclofen formulations in healthy male subjects .
abstract: BACKGROUND
  Baclofen is used as a skeletal muscle relaxant for multiple sclerosis patients. It depresses the transmission of monosynaptic and polysynaptic reflex by stimulating GABAβ(gamma-aminobutyric acid) receptors.
  
  
  OBJECTIVE
  The aim of this study was to compare the pharmacokinetic characteristics of two 10-mg baclofen formulations and to assess bioequivalence.
  
  
  METHODS
  A randomized, single-dose, two-period, two-sequence crossover study was conducted in healthy male subjects. Each subject received the test or reference formulations. After washout period, all subjects received the alternative formulation. Blood samples were collected for up to 24 hours after the dose in each period. Pharmacokinetic (PK) parameters, including tmax, Cmax, and AUClastwere calculated by noncompartmental methods. The geometric mean ratio (GMR) of the test to the reference formulation and its 90% confidence interval (CI) for Cmaxand AUClastwere calculated for assessment of bioequivalence.
  
  
  RESULTS
  A total of 22 subjects completed the study. The median tmaxof the test and the reference formulation were 1.50 and 1.25 hours, respectively. The mean (± SD) Cmaxof the test and the reference formulation were 141.401 ± 29.447 ng/mL and 138.837 ± 31.392 ng/mL, respectively. The mean (± SD) AUClastof the two formulations were 702.404 ± 82.149 ng×h/mL and 726.803 ± 90.638 ng×h/mL, respectively. The GMR (90% CI) of the test to the reference formulation for the Cmaxand AUClastwere 1.0306 (0.9564 - 1.1106) and 0.9674 (0.9437 - 0.9916), respectively.
  
  
  CONCLUSIONS
  The two different baclofen 10-mg formulations had similar PK profiles and were bioequivalent based on Cmaxand AUClast. .
authors.forename: Sumin
authors.initials: S
authors.lastname: Yoon
authors.forename: SeungHwan
authors.initials: S
authors.lastname: Lee
authors.forename: Kyung-Sang
authors.initials: KS
authors.lastname: Yu
authors.forename: Sung-Vin
authors.initials: SV
authors.lastname: Yim
authors.forename: Bo-Hyung
authors.initials: BH
authors.lastname: Kim
mesh_terms: D000328:Adult; D019540:Area Under Curve; D001418:Baclofen / Q000008:administration & dosage / Q000009:adverse effects / Q000493:pharmacokinetics*; D018592:Cross-Over Studies; D004339:Drug Compounding; D006207:Half-Life; D064368:Healthy Volunteers; D006801:Humans; D008297:Male; D008657:Metabolic Clearance Rate; D008875:Middle Aged; D008954:Models, Biological; D009125:Muscle Relaxants, Central / Q000008:administration & dosage / Q000009:adverse effects / Q000493:pharmacokinetics*; D056910:Republic of Korea; D013810:Therapeutic Equivalency
chemical_list: D009125:Muscle Relaxants, Central; D001418:Baclofen