Doxycycline calcium [USAN], Doxycycline calcium (internal use), C22H24N2O8.2Ca, Doxycycline calcium [USAN:USP], DOXYCYCLINE CALCIUM, Vibramycin calcium, EINECS 302-088-9, 2-Naphthacenecarboxamide,4-(dimethylamino)-1,4,4a,5,5a,6,11,12a-octahydro-3,5,10,12,12a-pentahydroxy-6-methyl-1,11-dioxo-,calcium salt (1:2),(4S-(4alpha,4aalpha,5alpha,5aalpha,6alpha,12aalpha))