Evaluation of the Effect of Disintegrant Distribution on the Dissolution Behavior of Pharmaceutical Tablets Using Raman Chemical Imaging.

In pharmaceutics, substandard drug manufacturing can sometimes occur. Usually, end-product release tests are conducted to detect defective products, but in many cases, they are not able to identify the root causes of quality defects. In recent years, chemical imaging techniques have been widely used to study quality defects by visualizing the distribution of components in solid dosage forms. However, in most studies, the causes are predicted from images of ingredients, and the impact of each factor is unclear. In this study, we prepared model tablets and intentionally changed only the distribution of disintegrants, and visualized this distribution using the Raman chemical imaging technique to evaluate the effect on the dissolution behavior of the tablets. We found that tablet disintegration occurs completely when the amount of disintegrant is sufficient to disintegrate the tablet and is distributed throughout the tablet, even if the distribution is not uniform. In contrast, if there was a large area where the disintegrant was not present, the tablet did not disintegrate sufficiently. This suggests that it is more important that a sufficient amount of disintegrant is present throughout the tablet rather than the degree of deviation of disintegrant distribution.