Characterisation of adhesional properties of lactose carriers using atomic force microscopy

Abstract

The atomic force microscopy (AFM) colloid probe technique was investigated as a method for the characterisation of adhesional properties of pharmaceutical powder surfaces. Lactose carriers used in dry powder inhaler (DPI) formulations were chosen for investigation since adhesion between the carrier surface and drug particles has been proposed to affect the dispersion of drug particles. Individual adhesion forces were determined by measuring the detachment forces in air between the colloid probe and the lactose particle surface. The colloid probe consisted of a silica sphere (10 μm diameter) attached to a V-shaped silicon nitride cantilever (spring constant, k = 0.42 N/m). Adhesion forces wer..