An overview of the state of the art on mitigating electrostatic interference during aerodynamic testing

Authors: ,

Background: In the pharmaceutical industry, electrostatic phenomena have been a topic of debate and research for many years. It has an impact on formulation performance, especially with powders. In most aerosol formation processes, like emission of droplets from a metered dose inhaler or particles from a dry powder inhaler, electrostatic changing occurs through either contact or friction between different particulates and material surfaces, as well as induction charging. Those electrostatic charges are omnipresent, very difficult to control, almost impossible to eliminate and it can significantly influence particle behavior.
Materials and Methods: A survey was developed based on the knowledge derived from literature and from expert opinions of the EPAG (electrostatic sub group) members. It consisted of two standardised questionnaires: 1) the effectiveness of different measures and, 2) methods used for minimising electrostatic interference during aerosol testing. A personal email invitation was send to representatives from 7 organisations. The survey asked participants to rank the measures used to reduce electrostatic according to their experience and knowledge, following a score system.
Results: The findings from this preliminary survey showed a lack of information and consensus on how to measure and minimise electrostatics during aerosol analysis, with the majority of the measures currently available not extensively used by pharmaceutical organisations.
Conclusions: How to measure and minimise electrostatics during aerodynamic testing of pharmaceutical is an important issue. Further extensive data will need to be collected to achieve a full overview of this problem and how it should be approached and standardised in the future.