Problems connected with the analytical investigation of drug substances

Many substances are described as monographs in Pharmacopoeias (Pharm.Eur, U SP, Pharm Jap,, Pharm. Int.). The most important step during the elaboratio n of a monograph represents the choice of the analytical procedure (method) for identification, purity testing and the assay of a drug substance, Spec ial attention must be paid to impurities that are known to possess or are s uspected to have toxic properties.