Analytical Technologies Singapore

One of the four Critical Quality Attributes (CQAs) that determine the safety, quality and efficacy of orally inhaled and nasal drug products (OINDPs), delivered dose is the total amount of drug emitted from the drug device that is available to the user, when the device is actuated correctly. 

The Delivered Dose Uniformity, or DDU, must be ensured within and between devices. DDU is measured by firing the test device into a sampling apparatus which contains a filter. The active drug caught on the filter is then dissolved in solvent and analysed using High-Pressure Liquid Chromatography (HPLC). Depending on the type of OINDP under test, different apparatus set-ups are required.

DDU of Metered-Dose Inhalers (MDIs)

Spacers & VHCS

The additional volume to help better dispense the aerosolised drug from MDIs


MDI testing the flow rate is fixed at an arbitrary value of 28.3 L/min

DDU of Dry Powder Inhalers (DPIs)

Dry Powder Inhalers (DPIs)

Test regime are more complex for DPIs than MDIs

DDU of Nebulisers


Delivered dose testing of nebulisers is carried out to determine the total amount of drug a patient

DDU of Aqueous Droplet Inhalers (ADIs)

Aqueous Droplet Inhalers (ADIs)

A new generation of inhaler designed to overcome low lung deposits and dose variability

DDU of Nasal Products

Dose Uniformity Sampling Apparatus (DUSA)

Simplifying the measurement of delivered dose uniformity testing for nasal sprays

Nasal Spray Dose Collector (NSDC)

Optimised internal geometry to eliminate splashback, drips and leakage following actuation to ensure complete spray dose capture every time.

Nasal Spray Waste Collector (NSWC)

Designed to collect high volumes of waste aerosol doses with no splashback onto the nozzle for safe and convenient disposal of waste drug product.