Use of software to facilitate pharmaceutical formulation - experiences from a tablet formulation

This paper exemplifies the benefits of using experimental design together with software to facilitate the formulation of a tablet for specific purposes, from screening to robustness testing. By applying a multivariate design for the screening experiments, many excipients were evaluated in comparatively few experiments. The formulation work was generally based on designed experiments. Most of the experiments were fractional or full factorial designs, generated and evaluated in Modde with the centre point replicated. The robustness of the formulation was evaluated with experimental designs on two different occasions. Tested flavours, were found to have limited influence on the important responses, which was key information in order to proceed with that particular composition. The formulation was also robust towards normal batch-to-batch variation of the excipients and the active pharmaceutical ingredient. A process step was investigated and, by applying experimental design and keeping in mind previous findings, important information could be gained from the study. The different studies yielded good and very useful models. Established relationships between design factors and responses provided information that was vital for the project. In cases of poor models, essential information regarding robustness was obtained. Copyright (C) 2004 John Wiley Sons, Ltd.