Glass Twin Impinger

The value of the Glass Twin Impinger, particularly with respect to routine quality control, is recognised by its retention as Apparatus A in Ph.Eur. 2.9.18.

Its usage is restricted to the assessment of nebulisers, MDIs and such DPIs where it can be demonstrated that a flow rate of 60 (+/-5) L/min is suitable.

Developed at GSK’s laboratories in Ware, UK, the Glass Twin Impinger is relatively easy to use and assemble. It operates on the principle of liquid impingement to divide the dose emitted from the inhaler into respirable and non-respirable fractions.

The non-respirable dose impacts on the oropharynx and is subsequently swallowed. This is considered as the back of the glass throat and the upper impingement chamber (collectively described as Stage 1). The remaining respirable dose penetrating the lungs is collected in the lower impingement chamber (Stage 2).

The upper impingement chamber is designed such that at a flow rate of 60 L/min through the impinger, the particle cut-off is 6.4 microns. Particles smaller than 6.4 microns pass into the lower impingement chamber.

For comprehensive product details, specifications and part numbers, please request a copy of our brochure “Quality Solutions for Inhaler Testing”.