Reliability of Arrhenius Equation in predicting vitamin A stability in multivitamin tablets.

Shelflife predictions of vitamin A stability in multivitamin tablets were calculated based on data obtained from the analyses of six multivitamin tablet preparations by the classical Arrhenius treatment. This approach gave excessive variation in the predictions. The same data were treated by a modified Arrhenius method, which reduced the variation. Long-term room temperature data show that incorrect slopes were predicted in three of the six sets of data with the modified approach. The data indicate that erroneous predictions can result when applying the Arrhenius treatment to accelerated data and that this approach should be used with extreme caution in establishing the expiration date of a multivitamin tablet product, especially where the limiting ingredient for expiration dating is a preprocessed raw material and not a single-entity chemical.