Non-linear mixed effects models for the evaluation of dissolution profiles.

The use of non-linear mixed effects models to describe dissolution data has been evaluated. A theoretical part is included to introduce this approach to scientists who are not familiar with this type of statistics. The standard settings of the statistical software package (S-plus) are used as much as possible. Several mathematical functions like the Weibull, logistic, first-order and Gompertz are employed as basis for the non-linear mixed effects models. Examples are given using dissolution data of immediate and extended release tablets. The results are compared with those obtained using linear mixed effects models.