title: Comparative bioavailability study of doxycycline hyclate (equivalent to 100 mg doxycycline) capsules (doxycin vs vibramycin) for bioequivalence evaluation in healthy adult volunteers.
abstract: This investigation was carried out to evaluate the bioavailability of a new capsule formulation of doxycycline (100 mg), doxycin, relative to the reference product, vibramycin (100 mg) capsules. The bioavailability was carried out in 24 healthy male volunteers who received a single dose (100 mg) of the test (A) and the reference (B) products after an overnight fast of at least 10 hours on 2 treatment days. The treatment periods were separated by a 2-week washout period. A randomized, balanced 2-way cross-over design was used. After dosing, serial blood samples were collected for a period of 48 hours. Plasma concentrations of doxycycline were analyzed by a sensitive and validated high-performance liquid chromatography assay. The pharmacokinetic parameters for doxycycline were determined using standard noncompartmental methods. The parameters AUC(0-t), AUC(0-infinity), Cmax, K(el), t(1/2) and Cmax/AUC(0-infinity) were analyzed statistically using log-transformed data. The time to maximum concentration (tmax) was analyzed using raw data. The parametric 90% confidence intervals of the mean values of the pharmacokinetic parameters: AUC(0-t), AUC(0-infinity), Cmax and Cmax/AUC(0-infinity) were within the range 80-125% which is acceptable for bioequivalence (using log-transformed data). The calculated 90% confidence intervals based on the ANOVA analysis of the mean test/reference ratios of AUC(0-t), AUC(0-infinity), Cmax and Cmax/AUC(0-infinity) were 95.98-109.56%, 92.21 to 107.66%, 93.90-112.56%, and 96.0 to 106.91% respectively. The test formulation was found bioequivalent to the reference formulation with regard to AUC(0-t), AUC(0-infinity), Cmax and Cmax/AUC(0-infinity) by the Schuirmann's two 1-sided t-tests. Therefore, the 2 formulations were considered to be bioequivalent.
authors.affiliation: College of Pharmacy, King Khalid University Hospital, College of Medicine, King Saud University, Riyadh, Saudi Arabia. ialsarra@ksu.edu.sa
authors.forename: I A
authors.initials: IA
authors.lastname: Alsarra
authors.forename: M S
authors.initials: MS
authors.lastname: Al-Said
authors.forename: K I
authors.initials: KI
authors.lastname: Al-Khamis
authors.forename: E M
authors.initials: EM
authors.lastname: Niazy
authors.forename: Y M
authors.initials: YM
authors.lastname: El-Sayed
authors.forename: K A
authors.initials: KA
authors.lastname: Al-Rashood
authors.forename: M J
authors.initials: MJ
authors.lastname: Al-Yamani
authors.forename: S A
authors.initials: SA
authors.lastname: Al-Balla
mesh_terms: D000284:Administration, Oral; D000328:Adult; D000900:Anti-Bacterial Agents / Q000097:blood / Q000493:pharmacokinetics*; D019540:Area Under Curve; D001682:Biological Availability; D002214:Capsules; D002851:Chromatography, High Pressure Liquid; D018592:Cross-Over Studies; D004318:Doxycycline / Q000031:analogs & derivatives* / Q000097:blood / Q000493:pharmacokinetics*; D006801:Humans; D008297:Male; D013810:Therapeutic Equivalency; D013997:Time Factors
chemical_list: D000900:Anti-Bacterial Agents; D002214:Capsules; D004318:Doxycycline