title: Bioequivalence study of two metformin formulations.
abstract: A randomized single-dose cross-over study was conducted on 24 healthy male volunteers to compare the bioavailability of two metformin (CAS 657-24-9) tablet formulations, Emiphage (test) and a commercially available original preparation (reference). A dose of 850 mg was administered after an overnight fast with a washout period of seven days. Eighteen blood samples were collected over 32 h. Metformin concentrations in deproteinized serum were determined by a locally validated High Performance Liquid Chromatographic (HPLC) assay, and pharmacokinetic parameters were analyzed by the standard non-compartmental method. Mean +/- SD maximum concentration (C(max)), time to reach maximum concentration (T(max)), area under the curve (AUC(0 --> t) and AUC(0 --> infinity)), and elimination half-life (t(1/2)) were 1.73 +/- 0.54 and 1.86 +/- 0.67 microg/ml, 2.6 +/- 1.2 and 2.0 +/- 1.0 h, 10.72 +/- 3.93 and 10.82 +/- 3.72 microg x h/ml, 11.53 - 4.14 and 11.6 +/- 3.84 microg x h/ml, and 3.1 +/- 0.7 and 3.1 +/- 0.9 h for the test and reference formulation, respectively. The parametric 90% confidence intervals on the mean of the difference (test - reference) between log-transformed values of the two formulations were 82.92% to 98.78%, 85.95% to 101.47%, and 77.82% to 100.4% for AUC(0 --> t), AUC(0 --> infinity), and C(max), respectively. The results indicate that the two formulations can be considered equivalent in the extent of absorption under fasting conditions.
authors.affiliation: Centre for Clinical Research, King Faisal Specialist Hospital and Research Centre, Riyadh, Saudi Arabia.
authors.forename: Samar
authors.initials: S
authors.lastname: Al Hawari
authors.forename: Eman
authors.initials: E
authors.lastname: AlGaai
authors.forename: Ahmed
authors.initials: A
authors.lastname: Yusuf
authors.forename: Abdelraheem
authors.initials: A
authors.lastname: Abdelgaleel
authors.forename: Muhammad M
authors.initials: MM
authors.lastname: Hammami
mesh_terms: D019540:Area Under Curve; D002626:Chemistry, Pharmaceutical; D002851:Chromatography, High Pressure Liquid; D018592:Cross-Over Studies; D006207:Half-Life; D006801:Humans; D007004:Hypoglycemic Agents / Q000008:administration & dosage* / Q000493:pharmacokinetics*; D008687:Metformin / Q000008:administration & dosage* / Q000493:pharmacokinetics*; D013607:Tablets; D013810:Therapeutic Equivalency
chemical_list: D007004:Hypoglycemic Agents; D013607:Tablets; D008687:Metformin