Comparative Pharmacokinetic of Two Levofloxacin Film-Coated Tablet Formulations: A Bioequivalence Study

Abstract

Background: Levofloxacin is a broad-spectrum antibiotic used to treat respiratory, soft tissue, and urinary tract infections. Generic formulations aim to reduce healthcare costs and improve accessibility but must demonstrate equivalent bioavailability to the originator drug. It remains unclear whether the new generic drug shares the same pharmacokinetic profile as the originator. Therefore, a bioequivalence study was conducted to evaluate the 500 mg generic Levofloxacin formulation against the reference product.

Methods:  The study was an single blind open-label, randomized, single-dose, two-periods, two-sequences crossover study under fasting conditions, with a one-week washout period with total subjects 16 healthy adults. Levofloxacin in plasma was measured using HPLC-VWD. The main parameters of bioavailability were assessed. AUC0-t, C_max, and AUC0-inf were analyzed with ANOVA and their 90% confidence interval of the geometric mean ratio between test and reference product were calculated. Meanwhile, T_max and T1/2 were compared nonparametrically using the Wilcoxon matched-pair test.

Results:   The value of 90% CI for C_max and AUC0-t were 92.10%-111.74% and 101.63%-108.58, respectively. The median T_max of test and reference drug were 1.00 and 0.88 hours, respectively. Meanwhile, the mean half-life of test and reference drug were 6.73±0.74 hours and 6.93±1.29 hours, respectively.  The 90% confidence intervals for C_max were (92.10–111.74%) and AUC0-t were 101.63–108.58% fell within the 80–125% acceptance range, demonstrating bioequivalence between formulations. 

Conclusion:  The 90% confidence intervals for C_max and AUC0–t were within the accepted range, with similar T_max and half-life values, confirming that the generic Levofloxacin 500 mg is bioequivalent to the reference product.

Keywords: bioequivalence, levofloxacin, pharmacokinetics