[Drug delivery system for the treatment of osteoporosis]

The number of agents for the treatment of osteoporosis has increased over the past few years allowing more and more differentiated therapy. Calcitonin, vitamin D3, bisphosphonate, estrogen, vitamin K2 and calcium are administered for the treatment of osteoporosis in Japan. The purpose of drug delivery system (DDS) is to provide a practical approach to increasing efficacy and minimizing side effects of the drugs. In fact by the development of DDS, topical administration, prodrug and targeting therapy are used in the treatment for osteoporosis. It is well known that calcitonin in susceptible to proteolysis in the intestine. So, calcitonin must be given intramuscular or subcutaneous injection for therapy. DDS of calcitonins is studying in many routes of administration, such as nasal, transdermal, ocular, oral, bronchial, rectal and vaginal.