Application of percolation theory to characterize the release behavior of carteolol matrix systems

The paper reports a study of the capability of the percolation theory to explain the influence of several formulation factors over the release behavior of carteolol hydrochloride inert matrix systems. For this purpose, previously prepared matrix systems have been employed. The characterization of these matrices by means of ''classical theories'' has been reported in previous papers. Similar percolation thresholds have been found (52.7%, 56.2 % v/v for the insoluble phase and 48.2% to 51.2% v/v for the soluble phase), even with changing formulation factors such as nature and percentage of polymer, type of wetting liquid and nature, and percentage of filler. This fact suggests an advantage far the application of percolation theory to the rationalization of pharmaceutical dosage forms design. From the obtained results, the characterization of a multicomponent system on the basis of percolation theory seems to be rather general. On the other hand, the relatively high percolation thresholds obtained can be attributed to the different particle sizes of the components according to correlated percolation models.