STORAGE-CONDITIONS FOR STABILITY TESTING IN THE EC, JAPAN AND USA - THE MOST IMPORTANT MARKET FOR DRUG PRODUCTS

Strong efforts have been undertaken to harmonise the requirements for the investigation of the stability of drug substances and drug products. Since the results of these investigations are used to assign labelling which properly reflects the stability of the substances/products under the climatic conditions encountered in the region of distribution and use, a thorough examination of the climatic conditions in the EC, Japan and the USA was conducted. According to this study, the EC, Japan and the USA may be practically assigned to a region for which there is an annual mean kinetic temperature of up to 25 degrees C. In fact, the climatic study indicates that 25 degrees C/60 per cent RH is general well above the mean kinetic temperature for the 35 major European, Japanese and American cities in the study. In addition the mean kinetic temperature encompasses the data in warehouses as well as measured seasonal and daily fluctuations up to and above the extreme temperature of 30 degrees C allowed by the USP definition of controlled room temperature. Based upon the above, it can therefore be concluded that long term controlled room temperature labelling for the USA, Japan and the EC can be accurately assigned by applying storage condition of 25 degrees C/60 per cent RH. Since the applied procedure to calculate and derive climatic conditions is based on the Arrhenius equation in the modified version of Hayne's relates mainly to chemical stability. In order to follow also organoleptic, and physico-chemical changes storage at higher conditions is necessary for up to 6 months (40-degrees-C/75 %) if a shelf live of at least three years is anticipated. The described procedure and derived storage conditions allow considerably savings in capacity and cutting costs.