ASAP for Non-Traditional Factors: Dissolution, Disintegration & Color

ASAP for Non-Traditional Factors: Dissolution, Disintegration & Color

Kenneth C. Waterman, Ph.D.
President, FreeThink Technologies, Inc.
Branford, CT USA

The Accelerated Stability Assessment Program (ASAP) approach of assigning storage times to hit the dissolution failure point at a range of temperatures and relative humidities (RHs) below the critical relative humidity (CRH) at each storage condition can be used to model the dissolution and disintegration stability of immediate-release tablet products.  Ambient condition stability could be determined based on a modified Arrhenius equation using the inverse of the failure times in place of rate constants.  This use of failure times, rather than a rate of change, was critical for modeling dissolution and disintegration stability because the onset of the failures was sudden.  In both cases, dissolution and disintegration failures were correlated with each other, but with greater storage times needed to effect destabilization for dissolution than disintegration.

Color change is modeled well by ASAP, with the challenge of changing qualitative descriptions to quantitative using colorimeter measurements.  In addition, specification limits need to be established. Even such changes in appearance as spots can be effectively quantitated and modeled with ASAP.  With these in place, ASAP can be used to determine such factors as formulation variation, packaging selection and climate zone sensitivity.