title: Bioequivalence of a new liquid formulation of benazepril compared with the reference tablet product.
abstract: OBJECTIVE
  To compare the bioequivalence and 'switchability' of two formulations of benazepril (tablet and liquid) after oral administration.
  
  
  METHODS
  Randomised cross-over design, followed by parallel comparison.
  
  
  METHODS
  Twelve mixed-breed dogs were administered either a tablet (Group A) or liquid formulation (Group B) of benazepril orally at 0.45 mg/kg daily for 4 days. With no washout period, the dogs then received the alternative treatment at the same dose for a further 4 days. Blood samples taken prior to treatment and serially after treatment were analysed for plasma concentrations of benazepril and benazeprilat and the activity and concentration of angiotensin-converting enzyme (ACE). The calculated percentage inhibition of ACE was defined as the primary outcome variable.
  
  
  RESULTS
  No statistically significant differences were found between groups A and B for any variable evaluated. The mean (± SD) percentage of ACE inhibition was 85.5 ± 7.04% for the liquid formulation and 85.9 ± 6.66% for the tablet formulation. The mean of the ratios was 1.00 (80% confidence interval 0.96-1.04). No evaluated effect term (sequence, formulation or period) had any statistical effect on any outcome variable.
  
  
  CONCLUSIONS
  This study supports a conclusion that, based on pharmacodynamic response, the liquid formulation of benazepril is bioequivalent to the reference tablet formulation. Further, the lack of a sequence effect supports the switchability of these two formulations.
authors.affiliation: Veterinary Hospital, Faculty of Veterinary Science, The University of Melbourne, 250 Princes Highway, Werribee, Victoria, 3030, Australia. kkelers@unimelb.edu.au
authors.forename: K
authors.initials: K
authors.lastname: Kelers
authors.forename: J L
authors.initials: JL
authors.lastname: Devi
authors.forename: G A
authors.initials: GA
authors.lastname: Anderson
authors.forename: P
authors.initials: P
authors.lastname: Zahra
authors.forename: J H
authors.initials: JH
authors.lastname: Vine
authors.forename: T
authors.initials: T
authors.lastname: Whittem
mesh_terms: D000284:Administration, Oral; D000806:Angiotensin-Converting Enzyme Inhibitors / Q000008:administration & dosage / Q000097:blood / Q000493:pharmacokinetics*; D000818:Animals; D019540:Area Under Curve; D001552:Benzazepines / Q000008:administration & dosage / Q000097:blood / Q000493:pharmacokinetics*; D018592:Cross-Over Studies; D004285:Dogs / Q000378:metabolism*; D005260:Female; D008297:Male; D007703:Peptidyl-Dipeptidase A / Q000097:blood*; D013810:Therapeutic Equivalency
chemical_list: D000806:Angiotensin-Converting Enzyme Inhibitors; D001552:Benzazepines; D007703:Peptidyl-Dipeptidase A; C052133:benazeprilat; C044946:benazepril
keywords: angiotensin-converting enzyme inhibitor; benazepril; dogs; pharmacokinetics; switchability