Variations in the adhesion force between a drug and carrier particles as a result of changes in the relative humidity of the air

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

“…This is especially useful in the case of irregular shaped particles where the contact area and adhesion force depends on the random orientation of the particles relative to the surface. Therefore, the centrifuge technique has been used to characterize the behavior of industrial powders in pharmaceutical [583][584][585][586][587][588][589] or food applications [590]. There are, however, also disadvantages of this technique.…”

The Influence of Relative Humidity on Particle Adhesion – a Review of Previous Work and the Anomalous Behaviour of Soda-lime Glass

“…The centrifuge technique employed by Zimon [10] has been used with good effect by Podczeck et al [11,12,13] to study the effect of relative humidity on the adhesion of pharmaceutical powders to various surfaces. In general, their findings were specific to each system studied, which were by nature very complex; their irregularly shaped particles ranged from hydrophobic to hydrophilic, with varying degrees of solubility.…”

“…Stone [4] Tomlinson [5,6] Bradley [7] McFarlane and Tabor [8] Zimon [10] Podczeck et al [11,12,13] Fisher and Israelachvili [14] Christenson [15] Chikazawa et al [17] Harnby et al [18] Sugarwara et al [23] Binggeli and Mate [24] Tang et al [30] Berard et al [32] Jones et al [34] Jones et al [37] Rabinovich et al Influence of press-on force and contact time studied. Difference between hydrophobic and hydrophilic surfaces identified.…”

Influence of Storage Humidity on the in Vitro Inhalation Properties of Salbutamol Sulfate Dry Powder with Surface Covered Lactose Carrier

“…Thus, the phenomenon can be explained by the formation of liquid bridges due to moisture condensation between particles. 10,23,24) When the surface covered lactose carriers were used, little decrease in the RP with increases in RH was observed, and RP remained high. This was probably because the surface of lactose particles covered with Mg-St-V had a high contact angle (Table 1), and the strong hydrophobicity prevented the adsorption of water molecules on it, so that the adhesion between drug particles and surface covered carrier particles did not increase markedly, allowed facilitation of drug detachment from carrier surface in inhalation.…”

“…However, only a few studies reported on comparison of storage humidity on the in vitro inhalation properties of dry powder inhalations using carrier particles. [8][9][10] We previously reported effects of a lactose carrier surface-covered with magnesium stearate on in vitro inhalation properties of salbutamol sulfate. 11) We, therefore, carried out basic studies on the influence of storage humidity on the in vitro inhalation property of salbutamol sulfate dry powder with surface covered lactose carrier, and we investigated the possibility of designing a DPI using the surface covered lactose carrier particles.…”