DPI Testing

Dry powder inhalers deliver medication as a powder rather than an aerosol, and the patient’s inspiratory flow drives de-agglomeration. Because of this, DPIs are tested at higher flow rates than pMDIs.

Testing at 60 and 90 LPM

Moving the A3G from pMDI to DPI testing takes about ten minutes. Minus stages -0, -1 and -2 snap into the stage column to achieve flow rates of 60 or 90 litres per minute, and the flow rate is set using the integrated mass flow controller, which induces laminar flow internally and holds the rate within 1% to 2%.

The same DPI conversion kit is available for manual Andersen Cascade Impactors, supplied with stages -0, -1 and -2.

What stays the same

• Automated concurrent dose collection from individual ACI stages and impaction plates
• Separate automated dose collection from the pre-separator and induction port
• Programmable solvent injection, washing and drying
• One micron 316 stainless steel woven wire mesh filter with zero bypass air flow
• CFR 21 Part 11 compliant software with method version control and audit trail

Equipment used

• A3G — Automated Andersen Cascade Impactor, DPI configuration
• DPI conversion kit for 60 LPM and 90 LPM, including stages -0, -1 and -2
• High capacity pre-separator in stainless steel or aluminium
• CHAKRAVAT — programmable shaker for induction ports, mouthpiece adapters and DUSA tubes