A new article by current and former FreeThink employees has been published in the scientific journal Pharmaceutical Development and Technology. The article, “Accelerated shelf life modeling of appearance change in drug products using ASAPprime®,” was co-authored by FreeThink Senior Scientist Kristina Flavier, former FreeThinkers James McLellan and Teslin Botoy, and FreeThink President Ken Waterman. You can find the full article here.


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 50–90°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 ΔE*), where a visual assessment of appearance changes likely to be noticeable was used to assign a ΔE* specification limit. ASAPprime® 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 ASAPprime® approach for accelerated stability studies are a fast, accurate approach to modeling appearance changes.