Dekati® ELPI+® | Dekati® BOLAR™ |
The charge carried by inhalation aerosols has been found to affect both inhaler device performance and lung deposition. The charge levels have been found to be affected by materials used in the device, drug and carrier material used in the formulation, interaction between surfaces and the device, but can also be affected by environmental conditions such as temperature and humidity. Thus far particle charge studies have focused on particle net charge measurements since a method for measuring bipolar charge has not been available. These studies have, however, indicated that net charge measurements give insufficient information as the particles generated by one inhaler device can simultaneously carry both positive and negative charge (Kannosto et al. 2013). The Dekati® BOLAR™ is the solution for this and is the first commercially available instrument that can simultaneously measure both negative and positive charges.
The BOLAR™ has been used to measured bipolar charge size distributions of various different inhalation aerosols. For example measured DPI results clearly indicate the insufficiency of net charge measurements as the detected positive and negative charge levels can be very high compared to detected net charge results. This completely new information can significantly improve our understanding of particles' behavior and knowledge on developing new inhaler devices.
Example of bipolar particle charge size distribution of a DPI.
The Dekati® Bipolar Charge Analyzer (BOLAR™) has been specifically designed for measuring bipolar charge of inhalation aerosols
including DPIs (Dry Powder Inhalers), MDIs (Metered dose inhalers) and Nebulizers. The BOLAR™ features include:
Hinds, Aerosol Technology 1998, second edition.
Karner, S, Urbanetz, N A: The impact of electrostatic charge in pharmaceutical powders with specific focus on inhalation-powders. Journal of Aerosol Science 2011, 42, 428–445.
Kannosto, J, Isherwood, H, Niemelä, V, Ukkonen, A: High Bipolar Electrical Charge Levels of Lactose Particles measured from DPI, RDD 2013
Glover, W, Chan, H K: Electrostatic charge characterization of pharmaceutical aerosols using electrical low–pressure impaction (ELPI). Journal of Aerosol Science 2004, 35, 755–764.
Kwok, P C.L. Noakes, T, Chan, H K: Effect of moisture on the electrostatic charge properties of metered dose inhaler aerosols. Journal of Aerosol Science 2008, 39, 211–226.
Telko, Martin J., Kujanpää J., Hickey A. J., Investigation of triboelectric charging in dry powder inhalers using electrical low pressure impactor (ELPI®), International journal of pharmaceutics, 336, 352–360, 2007.
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