A novel bending point criterion for dissolution profile interpretation

A novel bending point criterion was developed and compared with a number of existing criteria for the interpretation of certain dissolution profiles; these comparison criteria were the percentage dissolved at a fixed time poi nt, the fitted Weibull parameters, and the area tinder the dissolution curv e (AUC). The statistical bending point model was applied to dissolution cur ves that showed linear dissolution. The bending point model is based on a g eneral linear model, and its confidence information is obtained using the v ariance-covariance matrix of the parameter estimates. Practically, three ti me points in the linear part and two time points on the plateau level are u sed for a reliable bending point estimation. A comparative study with three batches and three storage conditions of slow-release mucoadhesive buccal t ablets was performed. The relative standard deviation (RSD) values of the b ending point were typically between 1% and 5%, which are considerably lower than the corresponding values of the other criteria (typically between 3% and 15%). The bending point criterion is considered robust and stable for t he characterization of certain dissolution profiles. Moreover, the bending point has a particular physical interpretation that is helpful in the frame work of the slow-release application of this buccal tablet.