Abstract: Novel cephalosporin compounds of formula (I) exhibit potent and broad antibiotic activities against Gram-negative and Gram-positive bacteria and various resistant bacteria: ##STR1##

Abstract: The present invention provides compounds of formula (I) and pharmaceutically or veterinarily salts thereof; ##STR1## wherein R.sub.1 is hydrogen or halogen or an organic group; R.sub.2 is hydrogen or an optionally substituted C.sub.1 -C.sub.6 alkyl, C.sub.3 -C.sub.6 cycloalkyl, C.sub.6 -C.sub.10 aryl or C.sub.7 -C.sub.14 aralkyl group;R.sub.3 is hydrogen or halogen, or an organic groupR.sub.4 is hydrogen or a group defined as R.sub.2 above or R.sub.4 taken together with R.sub.3 constitutes a C.sub.2 -C.sub.6 alkanediyl or an alkanediyl radical optionally substituted by methyl or phenyland X is either oxygen or sulphur or NR.sub.6, wherein R.sub.6 is either hydrogen or a group as defined for R.sub.2. A process for their preparation by cyclization of appropriate intermediates is also described.The compounds of formula I and the pharmaceutically and veterinarily acceptable salts thereof are elastase inhibitors.

Abstract: The subject compounds, which are adapted for the site-specific/sustained delivery of centrally acting drug species to the brain, are:(a) compounds of the formula[D-DHC] (I)wherein [D] is a centrally acting drug species, and [DHC] is the reduced, biooxidizable, blood-brain barrier penetrating lipoidal form of a dihydropyridine.revreaction.pyridinium salt redox carrier, with the proviso that when [DHC] is ##STR1## wherein R is a lower alkyl or benzyl and [D] is a drug species containing a single NH.sub.2 or OH functional group, the single OH group when present being a primary or secondary OH group, said drug species being linked directly through said NH.sub.

Abstract: The compounds having a 4,11-dioxo-3-oxa-8(or 7)-thia-1-azatricyclo[7,2,0,0.sup.2,6 ]undecane-2-carboxylic acid skeleton as the base structures, their esters and their salts are useful antibacterial agents.

Abstract: The compounds having a 4,11-dioxo-3-oxa-8(or 7)-thia-1-azatricyclo[7,2,0,0.sup.2,6 ]undecane-2-carboxylic acid skeleton as the base structure, their esters and their salts are useful antibacterial agents.