Abstract: A fast disintegrating controlled release oral composition comprising a core material containing cefuroxime axetil present as controlled release form, the cefuroxime axetil being provided with an outer coating of a copolymer selected from aqueous dispersions of enteric methacrylic acid and methacrylic acid esters anionic copolymers having carboxyl group as the functional group or mixtures thereof and an inner coating of a sustained-release copolymer selected from aqueous dispersions of acrylate and methacrylate pH independent copolymers having quaternary ammonium group as a functional group or mixtures thereof, and optionally probenecid. Additionally, the coating composition may contain plasticizers. The composition is suitable for once daily administration.

Abstract: A fast disintegrating controlled release oral composition comprising a core material containing cefuroxime axetil present as controlled release form, the cefuroxime axetil being provided with an outer coating of a copolymer selected from aqueous dispersions of enteric methacrylic acid and methacrylic acid esters anionic copolymers having carboxyl group as the functional group or mixtures thereof and an inner coating of a sustained-release copolymer selected from aqueous dispersions of acrylate and methacrylate pH independent copolymers having quaternary ammonium group as a functional group or mixtures thereof, and optionally probenecid. Additionally, the coating composition may contain plasticizers. The composition is suitable for once daily administration.

Abstract: A process for the stereospecific synthesis of keto-enol tautomeric mixture of p-nitrobenzyl (1R,6R,7R)-7-phenoxyacetamido-3-oxo-3-cepham-4-(R/S)-carboxylate-1-oxide and p-nitrobenzyl (1R,6R,7R)-7-phenoxyacetamido-3-hydroxy-3-cephem-4-carboxylate-1-oxide is described. These compounds are valuable intermediates for the synthesis of cephalosporin antibiotics e.g. cefaclor.

Abstract: A process for the stereospecific synthesis of keto-enol tautomeric mixture of p-nitrobenzyl(1R,6R,7R)-7-phenoxyacetamido-3-oxo-3-cepham-4-(R/S)-carboxyl ate-1-oxide and p-nitrobenzyl(1R,6R,7R)-7-phenoxyacetamido-3-hydroxy-3-cephem-4-carboxylat e-1-oxide is described. This process comprisesa) reaction of 7-phenoxyacetamido-3-exomethylene-cepham-4-carboxylic acid p-nitrobenzyl ester with ozone in a inert solvent such as acetone, or methylethyl ketone optionally in the presence of a protic solvent such as methanol, acetic acid or isopropanol at a temperature ranging from -90.degree. C. to -40.degree. C. to give the corresponding ozonide and,b) decomposition of the ozonide to keto-enol tautomeric mixture of p-nitrobenzyl(1R,6R,7R)-7-phenoxyacetamido-3-oxo-3-cepham-4-(R/S)-carboxyl ate-1-oxide and p-nitrobenzyl(1R,6R,7R)-7-phenoxyacetamido-3-hydroxy-3-cephem-4-carboxylat e-1-oxide without use of any reducing agent.

Abstract: An improved method for the preparation of 2-chloro sulfinyl azetidin-4-one of the formula: ##STR1## wherein R is: hydrogen; C.sub.1 -C.sub.3 alkyl; halomethyl; cyanomethyl; phenyl; substituted phenyl; phenoxy, benzyloxy- or substituted benzyl; a group of the formula R.sub.2 --O--wherein R.sub.2 is t-butyl, 2,2,2-trichloroethyl, benzyl or substituted benzyl; a group of the formula R.sub.3 --(O).sub.n --CH.sub.2 wherein R.sub.3 is phenyl or substituted phenyl. The 2-chlorosulfinylazetidin-4-one is prepared by reacting a penicillin sulfoxide ester of the general formula ##STR2## wherein R and R.sub.1 have the meanings defined above with an N-chloro halogenating agent in an inert organic solvent. The reaction is carried out in the presence of an acid scavenging amount of a phosphate or hydrogen phosphate of an alkali metal, alkaline earth metal, ammonium, quaternary ammonium or mixtures thereof.