DPI DUSA (USP Apparatus B)

For inhalers containing multiple doses, a test for dose content uniformity over the entire contents is required. The test also measures total discharges claimed by the product label. The sample collection system utilised is the Dosage Unit Sampling Apparatus (DUSA) collection tube. Primary parts include a fine particulate filter holder, main chamber with side pressure tap, end cap sets (solid and with vacuum hose connector), gasket seals and an inlet to hold the preferred mouth piece adaptor.

Popular closures techniques include the quick turn bayonet-style or screw-style cap. Custom designs available while following critical guidelines.

Material options: Delrin or Teflon.


The Dosage Unit Sampling Apparatus, DUSA-MDI, has been designed from specifications laid down in the various pharmacopoeia for the sampling and testing of pressurised Metered Dose Inhalers. It is used to perform those tests specified by the relevant compendial standards – “Total Number of Dis-charges per Container or Inhaler”, “Dose Uni-formity” and “Dose Uniformity Over the Entire Contents” as well as those tests designed to simulate the performance of the inhaler during actual use.