Development of Subcutaneous and Intramuscular Formulations of Calcium Alendronate Salts

Poorly soluble calcium-alendronate salts were prepared and investigated as potential candidates for subcutaneous or intramuscular formulations. Three such formulations containing calcium-alendronate salts with different stoichiometries were developed for testing in safety, disposition and efficacy studies in animals. All formulations demonstrated a drastic reduction in pain on injection and tissue damaging propensity compared to the soluble salts of ABP. All three were efficacious and showed prolonged absorption from the injection site with the deposition of a large percentage of the dose into the bone. Complex formation between alendronate and calcium was also studied.