How has the development of new analytical technologies influenced the quality criteria and standards for the uniformity of
dosage units? Have more accurate systems led to greater focus on tablet scoring?
Tablet scoring enables patients to control their drug dosage and could potentially deliver cost savings for healthcare providers.
It also makes larger tablets easier to swallow. However, the production of a scored tablet undoubtedly adds complexity to
the manufacturing process. This issue was brought into focus by recent FDA guidance on tablet scoring, for both general tabletting,
and more specifically, the manufacturing of generics.
Whilst a key aspect of tablet splitting has always been on how uniformly the active ingredient is distributed within the finished
product, it is equally important to understand how to produce tablets with the required mechanical integrity and properties.
Advances in spectroscopic techniques, such as near infrared (NIR) and laser-induced breakdown spectroscopy (LIBS), mean that
it is now possible to analyse content uniformity across the surface of a tablet. In addition, advances in powder characterisation
techniques can assist in the development of truly robust manufacturing processes.
Poor content uniformity is often attributed to the difficulty of achieving a homogeneous blend to begin with, which may be
because the active ingredient is present at very low levels, or is cohesive and prone to agglomeration. Alternatively, if
the API has significant particle size or density difference to the excipients in the blend, it may be liable to segregation
post blending. Dynamic powder characterisation can help optimise the blending process (1) and also predict the likelihood
of segregation. It therefore brings real insight into how to address these issues.
Furthermore, dynamic parameters in combination with shear and bulk properties, support a comprehensive understanding of powder
behaviour, whether during the blending process itself, or when processed through the tablet press. Together these properties
help manufacturers to rationalise and control powder performance during discharge from the hopper, whilst flowing through
the feed frame, and during filling of the die. In addition, they provide information relating to the compressibility characteristics
of the blend, as well as quantifying the ease with which air is entrained and released, both of which impact finished tablet
quality. This information can be extremely helpful in ensuring compatibility between the process equipment selected and the
properties of the blend, a match that is crucial for ensuring content uniformity in scored tablets.