The inspection of manufacturing facilities is required to ensure that good manufacturing practices are followed at all times. In assessing manufacture, the inspector is required to pay particular attention to raw materials, manufacturing procedures, sterile operations, packaging and labelling, in-process quality control, personnel and storage facilities. Special attention should be paid to any alterations of the master formula and manufacturing procedures.

An additional mechanism of drug quality surveillance at the time of manufacture is the batch control (batch certification) of some types of drugs. According to this procedure each batch of a drug, after being declared by the manufacturer as fully conforming to quality specifications, is “put in quarantine” while a random sample is taken and analysed by a governmental drug control laboratory for confirmation of its quality. The batch is released only after a satisfactory result is obtained. Such a mechanism, which calls for a duplication of the manufacturer’s control efforts by the governmental authorities, is usually restricted to specific types of drugs, such as those that are potent but highly labile. It is usually phased out once the quality level of manufacture is considered sufficiently uniform by the drug control agency.