To evaluate the bioequivalence and safety of colchicine tablets under fasting and fed conditions in Chinese healthy participants.

A single-center, randomized, open, single-dose, two-formulation, two-period, two-sequence crossover design was adopted, enrolling 72 healthy participants, with 36 healthy participants in each group for fasting and fed conditions. Single oral dose 0.5 mg of test formulation (T) or the reference formulation (R) was taken across two periods，respectively. Plasma concentration of colchicine was determined using ultra-high performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS). The pharmacokinetic parameters were calculated and the bioequivalence was evaluated using the non-compartmental model in Phoenix WinNonlin 8.2 software.

The main pharmacokinetic parameters of a single oral colchicine tablet under fasting condition for T and R were as follows: C_max were (2.70±0.88) and (2.54±0.87) ng·mL^-1，t_max were 0.98 (0.48, 2.00) and 0.98 (0.73, 2.48) h，t_1/2 were (29.54±5.46) and (29.67±4.86) h，AUC_0-t were (18.40±5.30) and (18.00±5.10) h·ng·mL^-1，AUC_0-∞ were (21.80±5.90) and (20.70±4.90) h·ng·mL^-1, respectively. The main pharmacokinetic parameters under fed condition for T and R were as follows: C_max were (2.49±0.84) and (2.58±1.00) ng·mL^-1，t_max were 1.48 (0.73, 3.98) and 1.48 (0.73, 4.00) h，t_1/2 were (31.79±4.69) and (30.65±4.91) h，AUC_0-t were (19.80±4.30) and (19.90±5.00) h·ng·mL^-1，AUC_0-∞ were (23.20±5.00) and (23.10±5.20) h·ng·mL^-1, respectively. The geometric mean ratios of C_max, AUC_0-t and AUC_0-∞ of the T and R formulations under fasting and fed conditions with a 90% confidence interval ranged from 80.00% to 125.00%.

Under both fasting and fed conditions, the colchicine tablet test formulation and reference formulation were bioequivalent in Chinese healthy subjects, and both were shown to be safe.