Abstract: Biphosphonic acids of general formula I: ##STR1## in which R is a fluorine atom of a linear or branched alkyl radical containing between 1 and 5 carbon atoms, which may also be substituted by one or more amino groups of fluorine atoms or both amino groups and fluorine atoms, R' is hydroxy or fluorine, and their salts with an alkali metal, an organic base or a basic aminoacid, exhibit valuable properties in the treatment of urolithiasis or in the treatment as inhibitors of bone reabsorption. The compound 4-amino-1-hydroxybutan-1,1-biphosphonic acid is between 100 and 300 times more active than Cl.sub.2 MDP.

Abstract: A pharmaceutical composition for the treatment of osteopathias is described which contains an effective amount of the active ingredient 6-amino-1-hydroxyhexane-1,1-diphosphonic acid or a pharmaceutically acceptable salt, ester, or a chelation complex with copper and inert carriers. The compositions are suitable for oral or systemic administration or topical application.