IntroductIon Cephalosporins are currently among the most widely prescribed antibiotics in hospitals.Development of these antibiotics has led to compounds with a broad spectrum of activity against both Gram-positive and Gram-negative bacteria and with low toxicity profles. Derivatives of penicillins, these drugs universally contain a -lactam ring (Figure 1). This four member ring is inherently strained and prone to hydrolysis and photolysis, limiting its stability.In addition to degradation products, isomers and dimers of the synthesis reagents are produced during manufacture of the compound. These impurities can persist in the drug product and many are of unknown toxicity.