DISINTEGRATION KINETICS OF TABLETS MONITORED BY MEANS OF A RESULTANT-WEIGHT APPARATUS

The weight and/or volume variations of a sample immersed in a fluid me dium can be determined with respect to time by means of a resultant-we ight measuring apparatus and method. The applicability of this in vitr o technique is examined herein for the monitoring of the disintegratio n process of tablets. Illustrative experiments obtained with different commercially-available tablets indicate that the information provided by the resultant-weight curves faithfully translates the macroscopic changes of the sample and its hydrodynamic evolution in time. Disinteg ration kinetics can be recorded even for instant release tablets, but the information becomes particularly interesting when the process adop ts a sequence with distinct steps, such as with tablets having a compo site structure (for example multi-layered modified release tablets, fi lm-coated tablets etc). The magnitude and duration of each step can be measured exactly and it is in turn possible to assess the different p arts of the tablets separately and to adjust their formulation or tech nological characteristics in accordance with the intended hydrodynamic behaviour.