Relative bioavailability of salmon calcitonin given intramuscularly.

Background: Salmon calcitonin, a polypeptide hormone, is used in the treatment of osteoporosis, hypercalcemia and Paget's disease. The purpose of this study was to evaluate the pharmacokinetics and relative bioavailability of two salmon calcitonin products, Miacalcic (Novartis Pharmaceuticals, Basle, Switzerland) and Calcinin (Purzer Pharmaceuticals, Taipei, Taiwan).

Methods: This was a randomized, single-dose, crossover study conducted under fasting conditions with a washout period of 1 week between doses. Ten healthy male subjects were enrolled in this study. Each subject received a 100 IU dose (20 micrograms; 50 IU/ampule x 2) of salmon calcitonin intramuscularly (i.m.) followed by collection of blood samples at specified time intervals. Serum salmon calcitonin concentrations were measured using a validated radioimmunoassay method with a detection limit of 15.0 pg/ml. Values for the area under the serum concentration from time zero to last time and infinity curve (AUC0-t and AUC0-infinity), peak concentration (Cmax), time to peak concentration, terminal first order rate constant, terminal half-life, mean residence time, total clearance divided by absolute bioavailability, onset time, maximal effect and duration were compared for each product.

Results: The 90% confidence intervals for AUC0-t, AUC0-infinity and Cmax after logarithmic transformation were 93.2% to 113.1%, 97.2% to 114.9% and 84.9% to 108.0%, respectively.

Conclusions: Based on the two one-sided tests procedure, we conclude that Miacalcic and Calcinin are bioequivalent.