INTRAPULMONARY DRUG-DELIVERY OF SALMON-CALCITONIN

Calcitonin (CT) and other bone-active peptides have been restrained in clinical use by the need for parenteral administration. Although nasa l and other transmucosal routes can be used for CT treatment, bioavail ability and bioactivity of the peptide thus delivered are limited. We have evaluated the intrapulmonary route (IP) for the delivery of salmo n calcitonin (SCT) in normal subjects. SCT was administered with a dry powder delivery inhaler. For comparison, each subject also received i ntramuscular (IM) SCT. Inhaled SCT produced significant hypocalcemia i n all subjects as did injected SCT, and the peptide could be readily m easured in serum by immunoassay. Compared by dose, IP SCT had 66% of t he bioactivity and 28% of the bioavailability of IM SCT. This intrapul monary route of administration should enhance the clinical acceptabili ty of SCT and could also be applicable to other bone-active peptides.