Use of percolation theory to predict the edge of failure for tablets
The percolation threshold model is
used to predict the behaviour of tablets based on particle-particle
interactions. If you consider a tablet composed of a matrix A, percolated by
particles of B; as the concentration of B in the tablet increases a threshold
will be reached where the tablet becomes a matrix of B percolated by particles
of A. Above this threshold a property phase transition occurs because of the
formation of clumps of B that become connected across the entire volume of the
tablet, i.e. forming an infinite cluster.
This percolation threshold is an edge of failure above or below which tablet properties such as tensile strength, dissolution rate or compactability) can step change. Predicting or measuring the percolation threshold, using statistical models or experimentation, is an evidence-based approach that can help get solid dosage forms designed faster. Once these edges of failure are identified, they can be avoided, and blends can be designed that offer higher chances of forming desired tablets.
To get a primer on percolation theory and how it can help design better dosage forms, start with these papers written by APC experts, packed with key references, experimental insights, and the methodologies you need to measure percolation threshold for your tablets and blends.