A Pharmacokinetic and Pharmacodynamic Comparison of Synthetic and Recombinant Oral Salmon Calcitonin

The aim of this study was to assess the bioavailability and pharmacodynamic efficacy of synthetic salmon calcitonin (ssCT) and recombinant salmon calcitonin (rsCT) in healthy postmenopausal women. The study was a single-blind, randomized study. Participants were 36 postmenopausal women 62 to 74 years old, randomly assigned to a comparison of dosing with ssCT (n = 12) or rsCT (n = 24) given in the morning at 08:00. Study parameters were plasma CT levels measured up to 2 hours postdose and changes in the bone resorption marker serum CTX-I and the cartilage degradation marker urine CTX-II measured up to 4 hours postdose. For both formulations, peak plasma concentrations were obtained 15 minutes after dosage, and no statistically significant differences in the uptake of CT were observed. Measurement of bone resorption and cartilage degradation markers displayed comparable responses, with AUCs of relative change of serum CTX-I of -250% x hours and relative change of urine CTX-II of -180% x hours during the 4-hour observation period. In conclusion, oral synthetic and recombinant calcitonin displayed comparable pharmacodynamic and kinetic properties.