Accelerated shelf life modeling of appearance change in drug products using ASAP.

An accelerated stability model approach was demonstrated to accurately predict the long-term shelf life of example drug substances and drug products (indigo carmine tablets and L-ascorbic acid powder) where appearance changes were shelf life-limiting. The products were exposed outside of packaging to conditions from 50 to 90 °C and 0-80% relative humidity for up to one month to accelerate appearance changes. The appearance changes of stressed samples were quantitated using the CIELAB color scale (calculated Δ*), where a visual assessment of appearance changes likely to be noticeable was used to assign a Δ* specification limit. ASAP software was employed to create an isoconversion paradigm, modeled in packaging by the moisture-modified Arrhenius equation, that predicted the color changes of the products within the error bars of the model to nine months at 25 °C/60% RH, 30 °C/65% RH, and 40 °C/75% RH. Overall, these case studies indicate that the ASAP approach for accelerated stability studies are a fast, accurate approach to modeling appearance changes.