Journal of Bioanalysis & Biomedicine

Comparative Bioavailability of a Generic and Two Compounded Naproxen Sodium Suspensions Administered to Rats

Abstract

Lílian Grace da Silva Solon, Gerlane Bernardo Coelho Guerra, Aurigena Antunes de Araújo, José Mário Barichello, José Pérez-Urizar and Luiz Alberto Lira Soares

The purpose of this study was to determine naproxen concentrations in rat plasma samples by HPLC and to compare the bioavailability of a generic and two compounded naproxen sodium suspensions (test 1 and test 2). Analysis was run at a fl ow rate of 1.2 mL.min^-1 with a mobile phase of acetonitrile: NaH2PO4 0.01 M pH 4.00 (50:50, v/v) at 280 nm, using a C18 column (150 mm x 4.6 mm, 5 μm). The calibration curve was linear (R2 = 0.9987) over the range of 0.25 - 200 μg.mL^-1. The precision for inter and intra-day analysis ranged from 2.46% to 12.39%. C_max, T_max and AUCt were 191.25 ± 11.17 μg.mL^-1, 1.00 ± 0.106 h and 2438.16 ± 291.34 μg.h.mL^-1 for the reference drug, 188.22 ± 24.78 μg.mL^-1, 1.06 ± 0.092 h and 1755.02 ± 228.90 μg.h.mL^-1 for test 1, and 160.50 ± 10.58 μg.mL^-1, 0.66 ± 0.102 h and 1955.28 ± 142.80 μg.h.mL^-1 for test 2. No signifi cant differences were found based on analysis of variance, with mean values and 90% CI of test2/reference ratio (C_max 83.92% and AUCt 80.19%). For test1/reference ratio, the result was C_max 98.41% and AUCt 71.98%. Based on these results, it can be concluded that the validated method was successfully applied to this study; the test 1 formulation failed to demonstrate a bioequivalence to the reference drug; however, the test 2 and reference naproxen sodium suspension were bioequivalent in terms of the rate and extent of absorption under these conditions.