Intranasal Delivery of the Peptide, Salmon Calcitonin

Abstract

Calcitonin is a polypeptide hormone normally secreted by the parafollicular cells of mammalian thyroid glands and by the ultimobronchial gland of birds and fish. The linear sequence of 32 amino acids found in the calcitonin of salmon origin has been synthesized. This synthetic salmon calcitonin (sCT) is currently formulated as a sterile solution for subcutaneous injection in the treatment of Paget’s disease, hypercalcemia, and osteoporosis. Paget’s disease is a disorder characterized by abnormal bone formation and resorption while hypercalcemia is an elevated serum calcium level, and osteoporosis is a loss of bone mass with increased fractures. Treatment calls for daily subcutaneous injections of salmon calcitonin over an extended period. The necessity of this daily injection is bothersome and inconvenient to patients. However, because the drug is a polypeptide subject to digestive degradation, it can not be given orally. Therefore, an alternate route of administration, such as intranasally, is attractive.