Storage conditions for stability testing of pharmaceuticals in hot and humid regions.

A review of the methodology for determination of the storage conditions for stability testing according to Schumacher/Grimm is presented in this paper. The purpose is to provide scientific information useful for the definition of storage conditions for stability testing of pharmaceuticals suitable to the region where the product will be dispensed. Special attention is given to stability testing in the new markets located in developing countries with very hot and humid climates. Finally, storage conditions for stability testing in the Brazilian regions were derived and examined comparatively with the guidelines of the world health organization (WHO) and regulatory bodies. The storage conditions were derived from the calculated values of the mean kinetic temperature and the relative humidity (RH). These parameters were estimated from daily values of dry and dew point temperatures of all Brazilian capitals from 1998 to 2002; collected in the morning (9 a.m.), in the afternoon (3 p.m.), and at night (9 p.m.). The Brazilian Center of Weather Forecast and Climatic Studies of the National Institute of Spatial Research (CPTEC/INPE) kindly furnished these data. Significant differences of the mean kinetic temperature (MKT) and relative humidity (RH) for Brazilian regions were observed. These results indicate the existence of a high climatic diversity between the Brazilian regions, making challenging the definition of a single storage condition for the stability testing. Some regions present RH values higher than 80%, giving support to the concerns of the WHO, indicating the necessity of revision of existing guidelines for stability testing mainly for very hot and humid regions.