Article: Better Wet Granulation: Development, Scale-Up And Manufacture

By Tim Freeman, Freeman Technology

Wet granulation is a common unit operation in the pharmaceutical industry yet accurate endpoint detection remains a challenge. Here we examine the contribution that dynamic powder rheometry can make, highlighting its ability to detect the transition from wet mass to granulate with the required sensitivity. Quantification of this transition point, with a measure that is independent of process scale, accelerates development and scale-up and improves manufacture.

Wet granulation converts very fine powders into granules with a much larger particle size. This yields benefits that include:

• Improved flow properties
• Reduced segregation (especially of active ingredients relative to excipients), and hence -
• Better content uniformity
• Reduced dust hazard
• Increased density and lower packed volume (since larger particles can pack more closely than smaller cohesive ones that tend to trap air).
• Improved properties during compression