Electrostatic characterisation of inhaled powders: Effect of contact surface and relative humidity

Elajnaf, Abdulmagid; Carter, Paul; Rowley, G.

doi:10.1016/j.ejps.2006.07.006

Cited by 71 publications

(41 citation statements)

References 14 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…21 Not only is the CE between two materials affected by RH, but also the net surface charges carried on some isolated metals or non-crystals will build up when RH increases. 22 In general, the natural environment is not completely dry, therefore usually a thin water film or island patch will adhere to solid surfaces of hydrophilic materials. 11,24 Therefore, it is necessary to investigate the dependence of CE on RH.…”

Section: Introductionmentioning

confidence: 99%

Effect of humidity on contact electrification due to collision between spherical particles

et al. 2016

View full text Add to dashboard Cite

This paper reports an experimental study of the contact electrification (CE) that happens when glass spheres of identical materials collide under different ambient relative humidity (RH) conditions. The experimental results indicate that the net charge on a sphere from a single collision is significantly altered by varying the RH level; the charge increases with increasing RH at low humidity, and then decreases at high RH conditions. The net charge reaches a maximum in the 20%–40% RH range. To explain the dependence of the CE on RH, we propose a model which yields predictions in agreement with the experimental data. The model also reveals how CE can be affected by temperature and surface absorption energy.

show abstract

Section: Introductionmentioning

confidence: 99%

Effect of humidity on contact electrification due to collision between spherical particles

et al. 2016

View full text Add to dashboard Cite

show abstract

“…To evaluate electrostatic forces and triboelectric charging, Faraday pails or wells are commonly used (Byron et al, 1997;Elajnaf et al, 2006;Karner and Urbanetz, 2011). Such a device basically consists of two conductive balls or wells of different sizes.…”

Section: Electrical Force Measurementsmentioning

confidence: 99%

Characterisation of dry powder inhaler formulations using atomic force microscopy

Weiss

McLoughlin

Cathcart

2015

International Journal of Pharmaceutics

View full text Add to dashboard Cite

A B S T R A C TInhalation formulations are a popular way of treating the symptoms of respiratory diseases. The active pharmaceutical ingredient (API) is delivered directly to the site of action within the deep lung using an inhalation device such as the dry powder inhaler (DPI).The performance of the formulation and the efficiency of the treatment depend on a number of factors including the forces acting between the components. In DPI formulations these forces are dominated by interparticulate interactions. Research has shown that adhesive and cohesive forces depend on a number of particulate properties such as size, surface roughness, crystallinity, surface energetics and combinations of these. With traditional methods the impact of particulate properties on interparticulate forces could be evaluated by examining the bulk properties. Atomic force microscopy (AFM), however, enables the determination of local surface characteristics and the direct measurement of interparticulate forces using the colloidal probe technique. AFM is considered extremely useful for evaluating the surface topography of a substrate (an API or carrier particle) and even allows the identification of crystal faces, defects and polymorphs from high-resolution images. Additionally, information is given about local mechanical properties of the particles and changes in surface composition and energetics. The assessment of attractive forces between two bodies is possible by using colloidal probe AFM.This review article summarises the application of AFM in DPI formulations while specifically focussing on the colloidal probe technique and the evaluation of interparticulate forces.2015 Elsevier B.V. All rights reserved.

show abstract

“…And, lactose monohydrate may dissolve and then recrystallize resulting in solid bridges producing stronger agglomerates that do not disperse (28). An increase in relative humidity in the range 0-86% produces a corresponding decrease in charge and adhesion values for API, lactose and DPI formulation during tribo-electrification in association with mixing vessel surfaces (29).…”

Section: Introductionmentioning

confidence: 99%

Dry Powder Inhalers: Study of the Parameters Influencing Adhesion and Dispersion of Fluticasone Propionate

Thi

Robins³

et al. 2012

AAPS PharmSciTech

View full text Add to dashboard Cite

Abstract. Interactions between particles are dependent on the physicochemical characteristics of the interacting particles but it is also important to consider the manufacturing process. Blending active pharmaceutical ingredient (API) with carrier is a critical stage that determines the blend homogeneity and is the first step towards obtaining the final quality of the powder blend. The aim of this work was to study parameters that influence the interactions between API and carrier in adhesive mixtures used in DPI and their effect on API dispersion. The study was done with fluticasone propionate blended with lactose 'Lactohale 200'. The study was based on the influence of the operating conditions (speed, mixing time, resting steps during mixing), the size of the carrier and the storage conditions on the blend properties and on the API dispersion. The quality of the blends was examined by analysing the API content uniformity. Adhesion characteristics were evaluated by submitting mixtures to a sieving action by air depression with the Alpine air-jet sieve. Aerodynamic evaluation of fine particle fraction (FPF) was obtained using a Twin Stage Impinger; the FPF being defined as the mass percentage of API below 6.4 μm. For good dispersion and therefore good homogeneity of the API in the carrier particles, speed and powder blending time have to be sufficient, but not too long to prevent the appearance of static electricity, which is not favourable to homogeneity and stability. The FPF increases with the decrease in the carrier size. The storage conditions have also to be taken into consideration. Higher humidity favours the adhesion of API on the carrier and decreases the FPF.

show abstract

Electrostatic characterisation of inhaled powders: Effect of contact surface and relative humidity

Cited by 71 publications

References 14 publications

Effect of humidity on contact electrification due to collision between spherical particles

Effect of humidity on contact electrification due to collision between spherical particles

Characterisation of dry powder inhaler formulations using atomic force microscopy

Dry Powder Inhalers: Study of the Parameters Influencing Adhesion and Dispersion of Fluticasone Propionate

Contact Info

Product

Resources

About