The advances achieved in the field of oral cephalosporins consist of improved bioavailability and enhanced intrinsic activity of the compounds. Oral absorption is facilitated either by creating prodrugs or by modifying the compound itself with addition of the alpha-amino group at position 7 on the cephem ring or of a vinyl group at position 3. Antibacterial activity and resistance to beta-lactamases are facilitated by the presence of an amino-2-thiazole heterocycle at position 7, associated with a methoxy-imino group or an oxy-imino-acetoxy group.