Measurement of interaction forces between individual powder particles using an atomic force microscope

Force measurements with the atomic force microscope: Technique, interpretation and applications

“…Sindel and Zimmermann [625] studied the adhesion between crystalline a-lactose monohydrate (Granulac 200) particles and a Granulac 200 pellet. Muster and Prestidge [626] measured adhesion forces of a hydrophobic colloid probe with different faces of the model pharmaceutical crystals N,n-octyl-D-gluconamide and sulfathiazole.…”

“…Local variations in adhesion may also allow identification of surface contaminants [1176][1177][1178][1179], the study of the influence of surface topography [625,701,1180] and roughness [1179] on adhesion, or the monitoring of surface heterogeneity during production steps of PEO layer grafted to a glass surface [1181].…”

Surface roughness contribution to the adhesion force distribution of salmeterol xinafoate on lactose carriers by atomic force microscopy

“…18 The AFM colloid probe technique enables the direct measurement of adhesion force between single particles and surfaces, and is becoming the method of choice to characterise particle adhesion in pharmaceutical systems. Recently, average adhesion forces in pharmaceutical powders, such as between a single small lactose particle and other lactose particle surfaces and compacted lactose disks, 19,20 between zanamivir drug particles and lactose carriers, 21,22 between beclometasone dipropionate (BDP), and a series of untreated and modified lactose surfaces 23 have been reported. However, while many replicates were determined, force distributions were not shown in these papers.…”

Characterisation of dry powder inhaler formulations using atomic force microscopy

“…5b). Sindel and Zimmermann (2001) for example demonstrated the deformation occurring to colloidal lactose probes when pressing them onto a lactose substrate. However, despite investigation, quantifying the impact of surface roughness and surface deformation on the force of adhesion has remained almost impossible (Cline and Dalby, 2002;Louey et al, 2001;Price et al, 2002).…”

“…3) to evaluate both the cohesive and adhesive interactions between materials used in drug delivery (Adi et al, 2007;Beilmann et al, 2007;De Boer et al, 2003a,b;Eve et al, 2002;James et al, 2008;Karner et al, 2014;Louey et al, 2001;Price et al, 2002;Sindel and Zimmermann, 2001;Tsukada et al, 2004;Young et al, 2009) and, quite recently, the mechanism of particle detachment (Cui and Sommerfeld, 2015). While three different scenarios describing the process of particle detachment-lift-off, sliding and rolling-are possible, a combination of colloidal probe measurements, simulations and computational modelling identified the rolling mechanism, closely followed by sliding, as the main mechanisms of particle detachment.…”