[Reconstruction of dissolution profiles of microcapsulated formulations by the mean and variance of dissolution times (author's transl)].

The influence of drug bioavailability on therapeutic regimens has increased the interest in in vitro dissolution testing and the quantitative interpretation of dissolution profiles. The mean and variance of in vitro dissolution times are appropriate parameters for discriminating different dissolution profiles. This article demonstrates that both parameters can easily and immediately be derived from dissolution data. Moreover, it is shown that the mean and variance of in vitro dissolution times define the parameters which appear in the model equation of a linear transport process. This model equation is proved to be valid for five formulations of N-carboxy-3-morpholinosydnone imine ethyl ester (molsidomine, Corvaton). It is applicable to dissolution data from a great variety of pharmaceutical formulations, provided that the dissolution process consists of a sequence of independent events. The model parameters are found by two different methods: by direct computation from the mean and variance of the dissolution times and by non-linear least-square parameter estimation. Both methods are compared on the basis of their resulting sum of squares (F-Test). The new pragmatic, statistical approach of data examination proves to be as effective as established routines.