Bioequivalence and Food Effect Assessment of Eltrombopag Olamine Tablets in Healthy Chinese Subjects: An Open, Randomized, Single-Dose, and Two-Period Crossover Study

Eltrombopag, a nonpeptide thrombopoietin receptor agonist, is primarily used for treating immune thrombocytopenic purpura. The aim of this study was to investigate the pharmacokinetic profile and food-drug interaction of test and reference eltrombopag olamine tablets among healthy Chinese volunteers. An open, randomized, single-dose, 2-period crossover design was employed, involving fasting and fed conditions with a 10-day washout period. Ninety-six healthy volunteers received a single oral dose of 25 mg of the 2 eltrombopag formulations, with 48 participants in each group: fasting volunteers and those consuming a high-fat, low-calcium meal. Plasma eltrombopag concentrations were analyzed using liquid chromatography-tandem mass spectrometry, and pharmacokinetic parameters were derived from the concentration-time profiles. The geometric mean ratios, with 90% confidence intervals, for the maximum plasma concentration, area under the concentration-time curve from time 0 to the last measurable concentration, and area under the concentration-time curve from time 0 to infinity fell within the bioequivalence acceptance criteria (80%-125%) under both fasting and fed conditions, indicating bioequivalence between the test and reference formulations. Administration of eltrombopag with a high-fat, low-calcium diet reduced the net systemic exposure by approximately 40%. Adverse events were recorded, and no serious adverse events were observed in either fasting or fed conditions. In conclusion, eltrombopag is well tolerated and exhibits a favorable safety profile in the Chinese population. The achievement of bioequivalence under fasting and fed conditions supports the demonstration of biosimilarity between the test and reference formulations.