# Assessment of the plasticity of dry granulated particles (mini-tablets) and its relationship to their tabletability

## TL;DR

This study examines how the plasticity of dry granulated particles affects their ability to form tablets, finding that granule deformation is key to tablet quality.

## Contribution

The study introduces a new approach to assess granule plastic deformation and its impact on tabletability using analytical powder compression.

## Key findings

- Granule plastic deformation is a key property for tabletability.
- Indentation hardness and α−1 coefficient showed no correlation.
- Analytical powder compression is preferred for measuring granule plastic deformation.

## Abstract

Mini-tablets of different proportions of α-lactose monohydrate (LAC) and microcrystalline cellulose (MCC) were prepared by uniaxial compaction and served as surrogate granules. The inverted Adams coefficient i.e., α−1 was derived from bulk mini-tablet compression data and used as an indication of granule plastic deformation. The correlation of the parameter to single granule deformability assessed from uniaxial single mini-tablet compression and macro-indentation hardness was investigated. Furthermore, the relationship between the plastic deformation parameters and the tabletability of mini-tablets were evaluated. An increased MCC concentration resulted in an increased indentation hardness and deformability of the mini-tablets, but no correlation was found between indentation hardness and the α−1 coefficient. Thus, the plastic deformation expressed during powder compression showed no relationship to the single specimen indentation hardness and plastic deformability. An increased indentation hardness tended to correspond to an increased tablet tensile strength, while the opposite applied for the α−1 coefficient. The trend of increased tablet tensile strength with higher MCC concentration was broken at the highest MCC concentration, i.e., for mini-tablets showing very limited fragmentation. It was concluded that granule plastic deformation is a key property for granule tabletability. It is suggested that granule plastic deformation should be assessed during granule engineering.

Unlabelled Image

•Plastic deformation of dry granulated particles is a key property for their tabletability.•Limited granule fragmentation may contribute to an improved tabletability.•The plasticity of the granule forming particles is critical for the granule plasticity.•Single granule plasticity did not correlate to plastic deformation during powder compression.•Analytical powder compression is the preferred approach to measure granule plastic deformation.

Plastic deformation of dry granulated particles is a key property for their tabletability.

Limited granule fragmentation may contribute to an improved tabletability.

The plasticity of the granule forming particles is critical for the granule plasticity.

Single granule plasticity did not correlate to plastic deformation during powder compression.

Analytical powder compression is the preferred approach to measure granule plastic deformation.