Pharmacokinetics, Bioequivalence and Safety of Cloperastine in Chinese Healthy Subjects Under Fasting and Postprandial Conditions.

Background: Cloperastine is a pivotal antibechic widely prescribed to treat cough caused by respiratory diseases. The present trial evaluated the pharmacokinetics (PK), bioequivalence (BE) and safety effects of the generic test (T) tablet of cloperastine after single-dose administration of cloperastine, compared with the original reference (R) tablet of cloperastine.

Objective: The purpose of this trial was to compare the PK, BE and safety of a test 10 mg versus the reference 10 mg formulation of cloperastine under fasting and postprandial conditions in healthy Chinese volunteers.

Methods: A single-centre, randomised, open, double-cycle, self-crossover, single oral administration Phase I trial was performed in healthy Chinese volunteers. A total of 60 subjects were enrolled in either the fasting (28 subjects) or the postprandial condition (32 subjects). Subjects randomly received a single dose of the T or R preparation (10 mg dose). Plasma concentrations of cloperastine were analysed by a validated LC-MS/MS method. The primary endpoints of the PK parameters were the area under the plasma concentration-time curve from zero to 72 h (AUC_0-72h), under the plasma concentration-time curve from zero to infinity (AUC_0-∞) and the maximal plasma concentration (C_max). The equivalence standard range (80.0-125.0%) was used to evaluate the BE of the two preparations. The safety parameter as secondary endpoint was mainly evaluated by the occurrence of adverse events (AEs).

Results: A total of 25 and 30 subjects in the fasting and postprandial conditions completed this clinical trial, respectively. The geometric mean ratio (GMR) of the T/R for the C_max, AUC_0-72h and AUC_0-∞ were 102.1%, 103.8% and 104.0% in the fasting condition, respectively. In the postprandial condition, the GMR of the T/R for the C_max, AUC_0-72h and AUC_0-∞ were 94.2%, 98.8% and 99.0%, respectively. All the values fell within the range (80.0-125.0%). The C_max and AUC_0-72h values of the T and R preparations in fasting and postprandial conditions were not statistically significant (P > 0.05). Furthermore, no serious adverse events (SAEs) occurred during the whole trial.

Conclusions: The T and R preparations were bioequivalent under both conditions. Food has no significant effect on the absorption of cloperastine. Moreover, T and R preparations were well tolerated. The trial registration number (TRN) and date of registrations were CTR20212515, 13 October 2021.