Pharmacokinetics and bioequivalence of Ezetimibe tablet versus Ezetrol®:an open-label, randomized, two-sequence crossover study in healthy Chinese subjects

Background Ezetimibe is a new class of antihyperlipidemic agent indicated for the prevention of atherosclerosis disease and for the treatment of hypercholesterolemia. Information on the pharmacokinetic profiles of ezetimibe tablet in healthy Chinese volunteers are lacking, and regulatory requirements necessitate a bioequivalence study of ezetimibe tablet versus Ezetrol((R)) in China. Methods A single-dose randomized, open-label, two-group, two-period crossover study was conducted in 59 healthy Chinese volunteers under fasting or fed conditions to assess the bioequivalence between two preparations. Eligible participants were randomly divided into fasted and fed groups. Blood samples were collected at specified time intervals, and the plasma concentrations of ezetimibe and ezetimibe glucuronide were determined by a validated liquid chromatography-tandem mass spectrometry (LC-MS/MS) method. PK and bioavailability parameters were estimated via non-compartmental methods. Adverse events were also recorded. Results Fifty-nine healthy volunteers were enrolled in the study. The main pharmacokinetic parameters of total ezetimibe in the plasma of the ezetimibe tablet (10 mg) and the Ezetrol((R)) (10 mg) after a single fasting administration: C-max were (65.73 +/- 47.14), (71.32 +/- 51.98) ng center dot mL(- 1); T-max were 1.75, 1.25 h; T1/2 were (17.09 +/- 13.22), (17.35 +/- 12.14) h; AUC(0-t) were (643.34 +/- 400.77), (668.49 +/- 439.57) h center dot ng center dot mL(- 1); AUC(0-infinity) were (706.36 +/- 410.92), (734.23 +/- 468.26) h center dot ng center dot mL(- 1). The main pharmacokinetic parameters of total ezetimibe in plasma of ezetimibe tablet (10 mg) and Ezetrol (R) (10 mg) after a fed administration: C-max were (83.38 +/- 38.95), (84.74 +/- 34.62) ng center dot mL(- 1); T-max were 2.50, 2.50 h; T1/2 were (22.56 +/- 12.68), (19.80 +/- 15.59) h; AUC(0-t) were (494.21 +/- 208.65), (536.69 +/- 209.11) h center dot ng center dot mL(- 1); AUC(0-infinity) were (573.74 +/- 252.74), (604.75 +/- 247.13) h center dot ng center dot mL(- 1). The main pharmacokinetic parameters C-max, AUC(0-t), and AUC(0-infinity) of the two drugs were analyzed by variance analysis after logarithmic transformation. The total ezetimibe under fasting state with 90% confidence intervals (CIs) were 85.29 similar to 97.19, 90.41% similar to 104.38%, and 90.81 similar to 106.05%; total ezetimibe in fed state were 86.36% similar to 109.17, 84.96% similar to 96.40, and 85.32% similar to 101.0%. The 90% CIs of the ratio of geometric means (GMRs) of C-max, AUC(0-t), and AUC(0-infinity) of Ezetrol (R) and ezetimibe tablet both fasting and fed conditions fell within the conventional bioequivalence criteria of 0.80-1.25. Both C-max and AUC met the predetermined criteria for assuming bioequivalence. No severe adverse events were observed. Conclusions The test ezetimibe tablet and Ezetrol((R)) were determined to be bioequivalent under both fasting and fed conditions in Chinese people.