title: Bioequivalence study of two different film-coated tablet formulations of losartan-hydrochlorothiazide in healthy volunteers.
abstract: The study was conducted in order to assess the bioequivalence of two film-coated formulations containing 100 mg of losartan (CAS 124750-99-8) and 12.5 mg of hydrochlorothiazide (CAS 58-93-5). Seventy-three healthy subjects were enrolled in a randomised, single-dose, open-label, two-way crossover study, with a minimum washout period of 7 days. A total of 21 blood samples were collected up to 36 h post-dosing. Losartan, losartan carboxy acid and hydrochlorothiazide levels were determined by liquid chromatography with tandem mass detection (lower limit of quantification: 1.01 ng/mL for hydrochlorothiazide, 2.02 ng/mL for losartan and 2.51 ng/mL for losartan carboxy acid). Pharmacokinetic parameters used for bioequivalence assessment (AUC(0-t) and Cmax as primary and AUC(0-inf) as secondary pharmacokinetic parameters) were determined from the losartan and hydrochlorothiazide concentration data using non-compartmental analysis. Data from losartan carboxy acid was reported and presented as supportive data. The 90% confidence intervals (obtained by ANOVA) for losartan were 97.05-118.48% for Cmax 100.76-106.10% for AUC(0-t) and 100.80-106.10% for AUC(0-inf) whereas for hydrochlorothiazide the 90% confidence intervals obtained were 103.94-115.33% for Cmax, 101.97-109.61% for AUC(0-t) and 101.77-109.02% for AUC(0-inf), and for losartan carboxy acid the intervals obtained were 98.31-107.82% for Cmax, 97.89-104.30% for AUC(0-t) and 98.06-104.30% for AUC(0-inf). All the 90% confidence intervals obtained for all the parameters assessed were within the predefined ranges (80-125%). Based on these results, it can be concluded that the evaluated formulations are bioequivalent in terms of rate and extent of absorption.
authors.affiliation: Medical Department, Grupo Tecnimede, Prior Velho, Portugal. dmed.ct.tecnimede@mail.telepac.pt
authors.forename: Rita
authors.initials: R
authors.lastname: Neves
authors.forename: Susana
authors.initials: S
authors.lastname: Almeida
authors.forename: Augusto
authors.initials: A
authors.lastname: Filipe
authors.forename: Ana Cristina Franco
authors.initials: AC
authors.lastname: Spínola
authors.forename: Zohreh
authors.initials: Z
authors.lastname: Abolfathi
authors.forename: Mercedes
authors.initials: M
authors.lastname: Yritia
authors.forename: Jordi
authors.initials: J
authors.lastname: Ortuño
mesh_terms: D000293:Adolescent; D000328:Adult; D000959:Antihypertensive Agents / Q000008:administration & dosage* / Q000097:blood / Q000493:pharmacokinetics*; D019540:Area Under Curve; D002138:Calibration; D002626:Chemistry, Pharmaceutical; D018592:Cross-Over Studies; D004311:Double-Blind Method; D004338:Drug Combinations; D006207:Half-Life; D006801:Humans; D006852:Hydrochlorothiazide / Q000008:administration & dosage* / Q000097:blood / Q000493:pharmacokinetics*; D019808:Losartan / Q000008:administration & dosage* / Q000097:blood / Q000493:pharmacokinetics*; D008297:Male; D008875:Middle Aged; D013608:Tablets, Enteric-Coated; D013810:Therapeutic Equivalency
chemical_list: D000959:Antihypertensive Agents; D004338:Drug Combinations; D013608:Tablets, Enteric-Coated; D006852:Hydrochlorothiazide; D019808:Losartan