Cephalosporin derivatives, and compositions containing them

Abstract

A compound of formula (I) or a pharmaceutically acceptable salt or in vivo hydrolysable ester thereof: ##STR1## wherein R is phenyl, 4-hydroxyphenyl, or a 5- or 6-membered heterocyclic ring containing up to three heteroatoms selected from oxygen, sulphur or nitrogen, optionally substituted with hydroxy, amino, halogen or C.sub.1-6 alkoxy; R.sup.1 represents hydrogen or C.sub.1-6 alkyl; R.sup.2 and R.sup.3 are the same or different and represent hydrogen, C.sub.1-6 alkyl, halogen, amino, hydroxy, or C.sub.1-6 alkoxy; X represents oxygen or sulphur; and A represents hydrogen, pyridyl, acetoxy, carbamoyloxy or a heterocyclicthio group; Their preparation and use is described.

Dependencies are inferred from the claim text.