The bioavailability of intranasal salmon calcitonin in healthy volunteers with and without a permeation enhancer.

Serum levels of radioimmunoactive salmon calcitonin (sCT) were determined in 10 healthy volunteers after intranasal administration (IN) of 100-, 205-, and 450-IU of sCT with 0.5% sodium tauro-24,25-dihydrofusidate (STDHF), a 200-IU commercial IN formulation, and a 100-IU intramuscular (IM) formulation. Relative to the IM dose, the bioavailabilities of the IN formulations containing 0.5% STDHF were 3.9, 7.9, and 7.4%, respectively. The 200-IU commercial formulation resulted in serum levels above the limit of detection in only 5 of 10 patients, with an average bioavailability of 1.6%.