Pharmacokinetics, Bioequivalence, and Safety Studies of Crisaborole Ointment in Healthy Chinese Subjects

The aim of this study was to evaluate the bioequivalence and safety of a single application of crisaborole ointment to test formulation and reference formulation in healthy subjects under fasting conditions. A total of 32 subjects were included and divided into 2 groups (test-reference; reference-test). A single-center, single-dose, 2-formulation, 2-period, 2-sequence, open, randomized, and crossover trial design was adopted. Eligible healthy subjects were applied with the test preparation (domestic crisaborole ointment) or the reference preparation (original crisaborole ointment), followed by a 7-day washout period. Blood samples were collected at predetermined time points before and after administration. After the development and verification of the blood concentration detection method for this study, the third-party supplier used liquid chromatography-tandem mass spectrometry to determine the plasma concentration of crisaborole and used SAS Version 9.4 software to calculate the pharmacokinetic parameters and evaluate the bioequivalence. In this study, the 90% confidence intervals of the geometric mean ratios of maximum concentration, area under the concentration-time curve over the dosing interval, and area under the concentration-time curve from time 0 to infinity were within the acceptable range (80%-125%). During the study, 5 subjects had 8 adverse events, and no serious adverse events were reported. In this study, the tested formulation of crisaborole ointment is bioequivalent to the reference formulation, and the safety is comparable.