Bioequivalence study of two formulations of etoposide in advanced lung cancer patients

The present randomized, two-period, cross-over bioequivalence study compared two soft capsules of etoposide (test and reference formulations), in treating 18 advanced lung cancer patients.

The pharmacokinetic parameters were determined based on the concentrations of etoposide, using HPLC with fluorescence detector. In each of the two study periods, a single dose of test or reference product was administered. The pharmacokinetic parameters assessed included area under the plasma concentration-time curve (AUC(0-12h)) from 0 to 12 hours, AUC(0-T) from time zero to infinity, the peak plasma concentration of the drug (C(max)), time to achieve C(max), and the elimination half-life.

Comparison of the test and reference products containing etoposide showed that geometric mean ratios (90% confidence interval (CI)) of AUC(0-T), AUC(0-∞)ž, and C(max) were 99.7% (92.1 - 103.7%), 99.4% (92.3 - 105.2%), and 101.5% (94.2 - 109.6%), respectively. Both AUC and C(max) ratio 90% CI of test and reference formulations were within its acceptable range for bioequivalence. The values of tmax and t1/2 were not found to have a statistically significant difference between the test and the reference drug (p > 0.05). No adverse events occurred in this bioequivalence study.

The two etoposide soft capsules (the test and reference formulations) were bioequivalent.