To evaluate the bioequivalence of clindamycin hydrochloride capsules test formulation and reference formulation in healthy subjects under fasting and postprandial conditions.

A randomized, open-label, single-dose, two-cycle crossover study was used in this study. A single dose of clindamycin hydrochloride capsules was administered in fasting and postprandial conditions, and the main pharmacokinetic parameters of clindamycin were determined by liquid chromatography tandem mass spectrometry to evaluate the bioequivalence of the two preparations.

Twenty- four healthy subjects were involved in the fasting and fed groups, respectively. The main pharmacokinetics (PK) parameters of the test formulation and reference formulation in the fasting group: C_max were (2 174.17±616.64) and (2 288.75±678.73) ng·mL^-1, AUC_0-t were (8 080.29±3 707.51) and (8 496.10±4 801.26) h·ng·mL^-1, AUC_0-∞ were (8 333.89±3 838.97) and (8 790.21±4 987.28) h·ng·mL^-1. The ratio of geometric mean and its 90% confidence interval were 95.27% (89.93%-100.93%), 97.75% (90.39%-105.70%), and 97.51% (90.13%-105.50%). The main PK parameters of the test formulation and reference formulation in the fed group: C_max were (1 860.00±349.00) and (2 069.04±504.25) ng·mL^-1, AUC_0-t were (7 829.93±1431.81) and (8 317.23±2 267.65) h·ng·mL^-1, AUC_0-∞ were (8 053.74±1 486.71) and (8 543.98±2 328.35) h·ng·mL^-1. The ratio of geometric mean and its 90% confidence interval were 91.56% (82.23%-101.95%), 96.41% (88.27%～105.31%), and 96.47% (88.14%～105.58%). The 90% confidence intervals of the geometric mean ratios of the main PK parameters of the test preparation and reference preparation for clindamycin hydrochloride capsules in the fasting group and fed group were all within 80.00% to 125.00%. The incidence of adverse events for the test and reference preparations in the fasting group were 25.00% and 20.80%, respectively, while in the postprandial group, they were 25.00% and 33.30%, respectively.

In the fasting and postprandial states, clindamycin hydrochloride capsules are bioequivalent to the original reference preparation.