Bioequivalence Comparison of Two Formulations of Fixed-Dose Combination Glimepiride/Metformin (2/500 mg)Tablets in Healthy Volunteers.

Glimepiride/metformin (2/500 mg) is an oral antihyperglycemic agent for the treatment of type 2 diabetes. A generic glimepiride/metformin (2/500 mg) fixed-dose combination (FDC) tablet was developed recently. This study was designed to collect data for submission to Korean regulatory authorities to allow the marketing of the test formulation. We evaluated the comparative bioavailability and tolerability of the test and reference formulations in healthy male adult volunteers. This single-dose, randomized, double-blind, two-way crossover trial was conducted at Bestian Medical Center in Bucheon, Korea. In total, 40 male Korean volunteers were enrolled. The subjects were randomized to receive an FDC tablet containing the glimepiride/metformin (2/500 mg) test or reference formulation, and pharmacokinetic(PK) parameters were measured. After a 1-week washout period, the other formulation was administered and the PK parameters were measured again. The Cmax and AUCt were determined from blood samples obtained at 0, 0.5, 1, 1.5, 2, 2.5, 3, 3.5, 4, 5, 6, 8, 12, and 24 h after drug administration. Bioequivalence was considered established if the 90% CIs of the geometric mean ratios(GMRs) of the test-to-reference formulations for Cmax and AUCt were within the predetermined regulatory range of 80-125%. In total, 40 healthy male subjects were enrolled and completed the study (mean [SD] age, 23.2[2.26]years[range, 19-30years];weight, 68.95[8.30]Kg[range, 52.0-87.0 Kg]; and height, 175.4[5.34] cm[range, 164-189 cm]). The GMRs(90% CI) of the glimepiride Cmax and AUCt were 1.006(0.947-1.069) and 1.010(0.953-1.071), respectively. For metformin, the values were 1.019(0.959-1.083) and 1.035(0.989-1.084), respectively. The test and reference formulations had similar PK parameters. The test formulation of glimepiride/metformin (2/500 mg) FDC tablets met the Korean regulatory criteria for bioequivalence.

Development of a population pharmacokinetic model to describe olmesartan medoxomil/ hydrochlorothiazide (20/12.5 mg) FDC tablet in male healthy South Korean subjects.

AIM: The objective of the present study was to develop population pharmacokinetic models for olmesartan medoxomil and hydrochlorothiazide and to investigate the influence of demographic factors on these population pharmacokinetics. METHODS: Plasma concentrations of olmesartan medoxomil and hydrochlorothiazide were measured in 41 healthy volunteers enrolled in our bioequivalence study by LC-MS/MS following oral administration of an olmesartan medoxomil/hydrochlorothiazide (20/12.5 mg) fixed-dose combination tablet. This data and covariates were subjected to nonlinear mixed-effect modeling analysis using the NONMEM software. Evaluation featured a visual predicted check and bootstrapping. RESULTS: The distributions of olmesartan medoxomil and hydrochlorothiazide were best fitted using a two-compartment model with no lag time and first-order elimination. When analyzing hydrochlorothiazide kinetics, we found that TCHO and CL/F were correlated, while. HB and Ka influenced olmesartan medoxomil modeling. All evaluations indicated that the pharmacokinetic profiles of olmesartan medoxomil and hydrochlorothiazide were adequately described using our PPK model. CONCLUSIONS: This study indicates that demographic factors influence the inter-individual variability in the disposition of the combination drug, and it might be more useful to apply it to the PK of olmesartan medoxomil/hydrochlorothiazide (20/12.5 mg) FDC tablets administered to patients with hypertension. *These two authors contributed equally to this work.

Effect of dissolved oxygen in alcoholic beverages and drinking water on alcohol elimination in humans.

Oxygen plays an important role in the metabolism of alcohol. An increased dissolved oxygen level in alcoholic beverages reportedly accelerates the elimination of alcohol. Therefore, we evaluated the effect of dissolved oxygen in alcohol and the supportive effect of oxygenated water on alcohol pharmacokinetics after the excessive consumption of alcohol, i.e., 540 ml of 19.5% alcohol (v/v). Fifteen healthy males were included in this randomized, 3 × 3 crossover study. Three combinations were tested: X, normal alcoholic beverage and normal water; Y, oxygenated alcoholic beverage and normal water; Z, oxygenated alcoholic beverage and oxygenated water. Blood alcohol concentrations (BACs) were determined by conversion of breath alcohol concentrations. Four pharmacokinetic parameters (C(max), T(max), K(el), and AUCall) were obtained using non-compartmental analysis and the times to reach 0.05% and 0.03% BAC (T(0.05%) and T(0.03%)) were compared using one-way analysis of variance (ANOVA) and Duncan's post hoc test. With combination Z, the BAC decreased to 0.05% significantly faster (p < 0.05) than with combination X. Analyzing the pharmacokinetic parameters, the mean K(el) was significantly higher for combination Z than for combinations X and Y (p < 0.05), whereas the mean values of C(max), T(max) and AUCall did not differ significantly among the combinations. Dissolved oxygen in drinks accelerates the decrease in BAC after consuming a large amount of alcohol. However, the oxygen dissolved in the alcoholic beverage alone did not have a sufficient effect in this case. We postulate that highly oxygenated water augments the effect of oxygen in the alcoholic beverage in alcohol elimination. Therefore, it is necessary to investigate the supportive effect of ingesting additional oxygenated water after heavy drinking of normal alcoholic beverages.