Dosage Unit Sampling Apparatus for Dry Powder Inhalers

The Dosage Unit Sampling Apparatus (DUSA) for DPIs is capable of sampling at a variety of flow rates up to 100 LPM.

The unit complies with USP Chapter <601> and EP Chapter <0671> specifications.

The standard collection tube and associated caps are manufactured from Dupont™ Delrin® (inert, resistant to most solvents, no extractables) with fluorinated ethylene propylene (FEP) encapsulated silicone o-ring seals which virtually eliminate leakage and extractables with the majority of drug recovery solvent systems.

Caps are quick-seal, ¼ turn to full positive stop, which are easy to assemble/disassemble reproducibly independent of the torque applied by the technician.

The sample collection tube is supplied with a filter support assembly that accommodates a 47 mm diameter filter, reliably produces an airtight seal, and readily connects to a vacuum pump via a hose barb.

According to the compendial method for delivered dose determination from a DPI, it is necessary to establish a 4 kPa pressure drop across the device and measure the corresponding flow rate through the inhaler. This pressure drop can be conveniently determined using a collection tube with a pressure tap (as shown above). Collection tubes without a pressure tap are also available for subsequent dose collections, once the test flow rate has been established.

DUSA for DPIs Starter Kit

The DUSA for DPIs Starter Kit (NE-D001) consists of:

  • One collection tube with a pressure tap
  • One collection tube without a pressure tap
  • One filter support assembly
  • One cap (with FEP encapsulated silicone seal) with hose barb to connect to a flow meter, which permits easy setting and confirmation of the target airflow rate prior to use of the DUSA
  • Two rinsing caps (with FEP encapsulated silicone seals)
  • A starter pack of 47 mm filters

In practice, most companies usually find it convenient and more efficient to supplement the starter kit described above with additional collection tubes (without pressure taps) and rinsing caps. In this mode of experimentation, the same filter support assembly can be used respectively with multiple DUSA’s to achieve faster sample preparation.

Usually, only one tube with a pressure tap is needed to determine the appropriate flow rate for the device. Collection tubes without pressure taps are less expensive, less prone to breakage or leakage, and minimized extractables when recovering drug samples from the apparatus.

Custom Actuator Adaptors

Custom molded mouthpiece adaptors are also available upon request to ensure a positive, reproducible seal and correct placement of the inhaler mouthpiece at the upstream opening of the DUSA. Customers must supply a sample DPI mouthpiece in order for us to fabricate a custom adaptor. Knowing your approximate rinsing solvent allows us to suggest the most compatible molding material.


  • NE-D001: DUSA for DPIs Starter Kit
  • NE-D002: Collection tube with pressure tap
  • NE-D003: Collection tube without pressure tap plus two rinsing caps (with FEP encapsulated silicone seals)
  • NE-D004: Two rinsing caps (with FEP encapsulated silicone seals)
  • NE-D005: Filter support
  • NE-D006: Cap (with FEP encapsulated silicone seal) with hose barb
  • NE-D007: Set of 10 FEP Encapsulated Silicone Seals
  • NE-D008: Set of 10 Low Density Polyethylene (LDPE) Seals for existing Nephele customers who prefer to retain the sealing system supplied with early versions of DUSA tubes
  • NE-D009: Pack of 47 mm Glass Fiber Filters (Quantity = 100)

Products are competitively priced. Please contact for a quotation, additional details or to discuss the availability of special order items.

All equipment is supplied according to our Terms and Conditions of Sale.