Bioequivalence of two quetiapine extended release tablets in Chinese healthy volunteers under fasting and fed conditions and effects of food on pharmacokinetic profiles

OBJECTIVE: The objectives of this study were to evaluate the bioequivalence of Quesero extended release (Quesero XR) tablets and Seroquel extended release (Seroquel XR) tablets under fasting and fed conditions and to determine the effect of food on the pharmacokinetic (PK) properties of Quesero XR or Seroquel XR in Chinese healthy volunteers. METHODS: A single-site, randomized, open-label, two-period crossover design with a 10-day washout period was conducted in 20 subjects under the fed and fasting studies. A single oral dose of 200 mg Quesero XR or Seroquel XR was given to the subjects after an overnight fast of 10 hours. Blood samples were taken at scheduled time spots from 0 hour pre dose to 36 hours post dose. Plasma concentrations of quetiapine were measured by a validated ultra-performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS) method. The PK parameters were calculated by non-compartment analysis using Phoenix WinNonlin software. RESULTS: On both conditions, no significant differences were found among the main PK parameters of the two preparations by analysis of variance (P>0.05); the Wilcoxon test of maximum peak plasma concentration (T(max)) showed no significant differences (P>0.05); the 90% confidence limit (CL) of lnC(max), lnAUC(0→36), and lnAUC(0→∞) fell within the acceptable range of 80%–125%. As compared with the fasting state, the T(max) was advanced and the mean maximum plasma concentration (C(max)), AUC(0→36), and AUC(0→∞) were also increased in the fed state; the geometric mean ratio and 90% CI of the main PK parameters fell outside the range of the CIs; analysis of variance showed significant differences in the other PK parameters except for apparent total clearance after oral administration (clearance rate; P<0.05). CONCLUSION: The two formulations of Quesero XR and Seroquel XR are bioequivalent under both fasting and fed conditions, and food may affect the PK profiles by increasing the rate and extent of absorption of Quesero XR or Seroquel XR in Chinese healthy volunteers.