An evaluation of fit factors and dissolution efficiency for the comparison of in vitro dissolution profiles

Dissolution efficiency (D.E.), the area under a dissolution curve between defined time points, and the lit factors (f(1) and f(2)) have been compared for the characterisation of dissolution profiles, using data from three batches of a product in nine different packs stored under two conditions. The factors f(1) and f(2) offer ease of calculation and a simple measure of similarity between pairs of dissolution profiles. This is well suited to the qualitative determination of 'similarity' as required by the FDA's SUPAC Guide. However, they do not provide information on individual batches, including their consistency. In contrast, D.E. does provide such information and is well-suited to making quantitative comparisons amongst batches. Because D.E. has a simple physical meaning, it is easier to interpret D.E. data than corresponding f(1) and f(2) results. The confidence limits in D.E. values provide a useful measure of the variability in batch dissolution and allow the statistical significance of difference in D.E. between pairs of batches to be determined. Both the above measures lead to the same conclusions regarding the similarity in protective power amongst the nine packs under test and to the value of added desiccant in maintaining the dissolution profile of the product when stored under high humidity conditions. It is concluded that D.E. offers a suitable alternative to the single point dissolution measurement for QC of immediate release products. (C) 1998 Elsevier Science B.V. All rights reserved.