medronic acid medronic acid medronic acid (conjugate base, medronate), also known as methylene diphosphonate, is the smallest bisphosphonate. its complex with radioactive technetium, 99mtc medronic acid, is used in nuclear medicine to detect bone abnormalities, including metastases. not to be confused with mildronate or minodronate. medronic acid names preferred iupac name methylenebis(phosphonic acid) other names methanediphosphonic acid; methylene diphosphonate; medronate; phosphonomethylphosphonic acid; mdp identifiers cas number 1984-15-2 n 3d model (jsmol) interactive image chebi chebi:43945 n chembl chembl180570 y chemspider 15308 y echa infocard 100.016.229 kegg d04887 y pubchem cid 16124 unii 73os0qin3o n comptox dashboard (epa) dtxsid8045696 inchi inchi=1s/ch6o6p2/c2-8(3,4)1-9(5,6)7/h1h2,(h2,2,3,4)(h2,5,6,7) ykey: mbkdynnuvrnnrf-uhfffaoysa-n y smiles o=p(o)(o)cp(=o)(o)o properties chemical formula ch6o6p2 molar mass 176.001 g·mol−1 melting point 199 to 200 °c (390 to 392 °f; 472 to 473 k) hazards lethal dose or concentration (ld, lc): ld50 (median dose) 45-50 mg/kg (i.v., mice, rabbits) except where otherwise noted, data are given for materials in their standard state (at 25 °c , 100 kpa). n verify (what is yn ?) infobox references