An Accelerated Storage Test for Predicting the Stability of Suspensions of Measles Virus Dried by Sublimation In Vacuo

Abstract

Several recent publications have described how the expiration dates of vitamin preparations stored at room temperatures may be predicted quantitatively on the results of short-term degradation studies at elevated temperatures (1–5). The fundamental studies of Garrett have been responsible for the greatest advances in this field (2). Briefly, the method is based on the observation that a suitable metameter of the potency (the potency itself or its logarithm) declines, at a selected temperature, linearly with time; further, that different rates of decline in potency (or its metameter) obtained at different temperatures are related to these temperatures and act in accordance with fundamental physical chemical principles (6). Based on the foregoing, thermal degradation should follow the logarithmic form of the Arrhenius relation with respect to absolute temperature (T): log k = -(ΔHa/2.303R)(1/T) (1) where k is the specific rate of degradation of the biologic material, R is the gas constant and ΔH_a is defined as the heat of activation.