A pharmaceutical composition for
oral administration comprising PTH, wherein the
in vitro release of PTH-when tested in a
dissolution test of
pharmacopoeia standard-is delayed with at least 2 hours and once the release starts, at least 90% w / w such as, e.g., at least 95% or at least 99% of all PTH contained in the composition is released within at the most 2 hours. The composition may also comprises a
calcium containing compound and / or a
vitamin, D. In particular, PTH is administered in combination with a
calcium-containing compound for the treatment or prevention of bone-related diseases, so that I) an effective amount of a
calcium-containing compound is administered to lower the
plasma level of endogenous PTH, and II) an effective amount of PTH is administered to obtain a
peak concentration of Pm once the endogeneous PTH level is lowered. This present a potential therapeutic or prophylactic
regimen for bone-related disorders including
osteoporosis.