Pharmacodynamic properties and bioequivalence of dalteparin sodium subcutaneous injection in healthy Chinese male subjects

1. Dalteparin sodium (DS) is a low molecular weight heparin that is widely used in the treatment of thromboembolism. The purpose of this study was to compare the pharmacodynamic properties and bioequivalence of the two formulations of DS with subcutaneous injection in healthy Chinese male subjects. 2. In this randomized, open-label, two-period crossover study, a total of 24 male subjects were recruited to receive single subcutaneous doses of test and reference DS injection in two different sequences (12 subjects each) with a seven-day washout period. Plasma samples were obtained at different time points after administration of the injection and measured by chromogenic substrate assay. The pharmacodynamic parameters including E-max, AUEC(0-T), AUEC(0-) and T-max were analyzed to evaluate the bioequivalence of two DS formulations. 3. The relative bioequivalence was 107.7 +/- 15.5 and 106.6 +/- 29.8 for Anti-Xa and Anti-IIa, two major active metabolites of DS, respectively. The 90% confidence intervals (CIs) of the geometric mean ratio (test/reference) of E-max, AUEC(0-T) and AUEC(0-) were 98.71-104.40%, 101.95-112.13% and 102.38-112.10% for Anti-Xa, and 100.88-110.42%, 95.76-112.62% and 92.24-111.32% for Anti-IIa, respectively, and all of the 90% CIs were within 80-125%. The T-1/2 of reference and test were 2.88 +/- 1.21h and 2.76 +/- 0.97h for Anti-Xa, 1.87 +/- 0.62h and 1.96 +/- 1.52h for Anti-IIa. 4. Based on the pharmacodynamic parameters and FDA Guidance on DS and regulatory criteria for bioequivalence, the test and reference formulations were bioequivalent in healthy Chinese male subjects.