Pharmacokinetic study with synthetic salmon calcitonin (Sandoz)

18 patients randomly divided into 3 groups of six each received 35 mug (140 M.R.C. Units) of synthetic salmon calcitonin intravenously, intramuscularly or subcutaneously. Plasma and urin concentrations were determined using the radioimmunoassay method. There was a rapid distribution phase of ca. 12 minutes after intravenous injection then an elimination half-life of 1.1 hours. The volume of distribution was 11 litres. The invasion half-life after intramuscular and subcutaneous administration was 12 and 11 minutes respectively and the elimination half-lives 1 and 1.5 hours, respectively. The bioavailability of the intramuscular and subcutaneous forms was found to be 66 and 71% respectively when areas under their plasma concentration/time curves were compared with the intravenous area.