Competing for water: A new approach to understand disintegrant performance

Area of Science:

• Pharmaceutical Sciences
• Materials Science

Background:

• Tablet disintegration understanding remains incomplete.
• The role of binders and soluble fillers in tablet disintegration is not fully elucidated.
• Existing theories on soluble filler influence, like viscosity increase, do not fully explain observations.

Purpose of the Study:

• To investigate the impact of soluble and insoluble fillers, binders, and disintegrants on tablet disintegration.
• To propose a new hypothesis explaining the interaction between excipients and water during disintegration.
• To provide a better understanding of tablet disintegration mechanisms.

Main Methods:

• Performed water uptake, force development, and water sorption experiments on tablets.
• Utilized tablets containing soluble (lactose) or insoluble (dibasic calcium phosphate - DCP) fillers.
• Incorporated four different binders and four different disintegrants.

Main Results:

• One disintegrant performed significantly worse with both filler types.
• Sodium starch glycolate showed the longest disintegration with DCP; croscarmellose sodium performed worst with lactose.
• Identified a correlation between filler type, disintegrant efficacy, and water binding.

Conclusions:

• Introduced the 'competition-for-water' hypothesis.
• Soluble fillers bind water molecules, hindering disintegrant function and affecting tablet disintegration.
• The hypothesis offers a framework to explain and predict tablet disintegration behavior.