Any pharmaceutical product can be subject to chemical or microbiological deterioration and the regulatory authorities will need to be shown the manufacturer's experimental evidence for their claimed shelf-life of the product. If, for example, the medicine is principally going to be used in the tropics, it should be able to withstand climatic conditions there for the duration of its claimed active life. Accelerated storage tests Instabilities in modern formulations are often detectable only after considerable periods of storage under normal conditions. Any problems encountered may require modifications to be made to the formulation or the packaging. For example, if an injection has been shown to be susceptible to oxidation, it may be necessary to seal it in glass ampoules under nitrogen.
Many pharmaceuticals have the potential of becoming contaminated by microorganisms during use.
If tablets are kept dry, they will not allow any microbes to flourish which may have come into contact with them during handling - but this will not be the case if they are stored under humid conditions. The British Pharmacopoeia lays down standards for such tests. The use of preservatives and the procedures for testing their efficacy are studied in Module phar2408 . The British Pharmacopoeia is published annually by Her Majesty's Stationery Office and is the authoritative collection of standards for medicines in the United Kingdom. It provides essential information for all those concerned with the quality of medicines and its standards are legally enforceable in the UK and most of the Commonwealth.