Bioequivalence of a Generic Nateglinide Formulation in Healthy Chinese Volunteers under Fasting and Fed Conditions: A Randomized, Open-Label, Double-Cycle, Double-Crossover Study

Abstract

<b><i>Introduction:</i></b> Nateglinide or <i>N</i>-(trans-4-isopropylcyclohexyl-1-carbonyl)-D-phenylalanine is a drug with a rapid hypoglycemic effect that is mainly used in the treatment of type 2 diabetes. Very few studies have assessed bioequivalence based on feeding status. This study aimed to assess the pharmacokinetic bioequivalence and safety of nateglinide-containing tablets (0.12 g) in healthy Chinese volunteers under fasting and fed conditions. <b><i>Methods:</i></b> The studies were performed in 2017–2018 in the Phase I Clinical Trial Ward of the Affiliated Hospital of Liaoning University of Traditional Chinese Medicine, China. Eligible Chinese volunteers received a single 0.12-g dose of the test or reference formulation, followed by a 7-day washout period and administration of the alternate formulation. Blood samples were collected at various time intervals, and plasma nateglinide concentrations were analyzed by liquid chromatography-tandem mass spectrometry. Then, the adverse events, laboratory test results, vital signs, and physical exam findings were compared between the 2 groups. <b><i>Results:</i></b> The ratios of the geometric means of C_max, AUC_0-t, and AUC_0-inf of the tested to reference preparations under fasting conditions were 105.03% (90% confidence interval [CI]: 99.53–110.83%), 104.02% (90% CI: 101.37–106.74%), and 104.04% (90% CI: 101.38–106.77%), respectively. The same ratios under fed conditions were 96.55% (90% CI: 85.80–108.65%), 103.08% (90% CI: 100.07–106.18%), and 103.07% (90% CI: 100.21–106.01%), respectively. The 90% CI values for C_max, AUC_0-t, and AUC_0-inf fell within the accepted range of bioequivalence (80.00–125.0%). Common adverse events included hypoglycemia, heart rate increase, palpitation, sweating, dizziness, and diarrhea. <b><i>Conclusions:</i></b> The test formulation (0.12 g) met the CFDA’s regulatory definition for bioequivalence to the reference formulation. Both formulations were well tolerated by healthy Chinese subjects. <b><i>Trial Registration:</i></b> This trial has been registered in the Chinese Clinical trial registry (ChiCTR2000030694), March 10, 2020.