Powder strength distributions for understanding de-agglomeration of lactose powders.

Purpose: The purpose was to calculate distributions of powder strength of a cohesive bed to explain the de-agglomeration of lactose.
Methods: De-agglomeration profiles of Lactohale 300(®) (L300) and micronized lactose (ML) were constructed by particle sizing aerosolised plumes dispersed at air flow rates of 30-180 l/min. The work of cohesion distribution was determined by inverse gas chromatography. The primary particle size and tapped density distributions were determined. Powder strength distributions were calculated by Monte Carlo simulations from distributions of particle size, work of cohesion and tapped density measurements.
Results: The powder strength distribution of L300 was broader than that of ML. Up to 85th percentile, powder strength of L300 was lower than ML which was consistent with the better de-agglomeration of L300 at low flow rates. However, ~15% of L300 particles had higher powder strength than ML which likely to cause lower de-agglomeration for L300 at high air flow rates.
Conclusion: Cohesive lactose powders formed matrices of non-homogenous powder strength. De-agglomeration of cohesive powders has been shown to be related to powder strength. This study provided new insights into powder de-agglomeration by a new approach for calculating powder strength distributions to better understand complex de-agglomeration behaviour.