Journal of Bioequivalence & Bioavailability

Abstract

Bioequivalence Study of Norfloxacin Tablets (Oranor® and Noroxin®) in Healthy Male Volunteers. A Single Dose, Randomized, Open-label, 2 x 2 Cross-over, in Fasting Conditions Study

Rosalba Alonso-Campero, Roberto Bernardo-Escudero, María Teresa de Jesús Francisco-Doce, Myriam Cortés-Fuentes, Gilberto Castañeda-Hernandez and Mario I. Ortiz

Background: Norfloxacin is a fluoroquinolone antibacterial agent suitable for oral administration. This study evaluates if the fasting bioavailability of two solid formulations of 400 mg of norfloxacin is equivalent for obtaining marketing approval from the Mexican regulatory agency. Objective: Establish and compare the comparable bioavailability of 400 mg norfloxacin coated tablets (Oranor) and 400 mg norfloxacin tablets (Noroxin) after administration of an oral dose, in fasting conditions, in healthy male subjects. Subjects and methods: This was a 2 x 2 cross-over, randomized, single-dose, open-label study which included 26 healthy male subjects under fasting conditions. In each of the two study periods (separated by a washout of 7 days) a single dose of test or reference drug was administered. Blood samples were taken up to 24 h post dose, the plasma was separated and the concentrations of norfloxacin were determined by a high performance liquid chromatography with fluorescence detection. Schüirmann’s unilateral double t- test and confidence interval of 90% to norfloxacin concludes that the bioavailability of Cmax and AUC results between the two treatments are equivalent. Results: All 26 subjects were included in the analysis mean ± SD age: 31±7.51 years, height: 168±6.95 cm, weight: 69.58±8.53 kg and body mass index: 24.37±2.02 kg/m2. All were Hispanic (Mexicans). The mean AUC 0-t , AUC 0- ∞, Cmax, tmax and t½ were 6228.18 ng/h/mL, 6658.62 ng/h/mL, 1436.19 ng/mL, 1.38 h and 6.51 h, respectively, for the test drug and 6706.32 ng/h/mL, 7161.03 ng/h/ml, 1470.14 ng/mL, 1.40 h and 6.55 h respectively, for the reference product. Conclusions: This single dose study in a small population of fasting, healthy subjects found no statistically significant differences in bioavailability (Cmax and AUC) between the test and reference products, meeting the National Ministry of Health regulatory requirements in México for assuming equivalence. Both formulations were well tolerated.