Flow test system

for research and developmentlaboratoryfor medical applications

Overview
Both MDIs and DPIs suffer from two inherent challenges: low lung deposition (typically 5–20%) and dose variability often caused by patient coordination or inspiratory effort. Soft Mist Inhalers (SMIs), also called Aqueous Droplet Inhalers (ADIs), actively aerosolise liquid to create a slow-moving “soft mist,” which can increase the fine particle fraction and reduce handling-related variability. As multi-dose liquid systems, SMIs may, however, present a risk of microbial contamination.

Delivered dose uniformity (DDU) testing notes
Because SMIs are active, aqueous-based devices, DDU testing for ADIs follows similar principles to MDI methods. DDU testing is typically performed at a constant test flow rate (example: 28.3 L/min) to assess dose consistency across repeated actuations and over device life. Copley supplies dedicated SMI DDU testing equipment for delivered dose collection and analytical recovery.

Key points

• Device type: Soft Mist Inhalers (SMIs) / Aqueous Droplet Inhalers (ADIs) — active aqueous aerosolisation producing a slow-moving aerosol cloud.
• Clinical benefits: generally higher fine particle fraction compared with MDIs and DPIs, potentially reducing dose variability linked to patient handling and coordination.
• Challenges: multi-dose liquid formulation can carry a risk of microbial contamination and require appropriate controls.
• Testing approach: DDU testing is carried out similarly to MDI protocols, typically at a constant flow rate (example: 28.3 L/min) to evaluate delivered dose consistency across repeated actuations and through the device life.

Products featured in this system

• Low Capacity Pump LCP7
• Breath Actuation Controller BAC 100i
• Inhaler Testing Workstation (ITW)
• Dose Uniformity Sample Apparatus (DUSA) for MDIs
• Flow Rate Sensor (FRS)
• Waste Shot Collector (WSC2)
• Mouthpiece Adapter

Semi-automation tools — benefits

• Improve testing efficiency and throughput
• Reduce operator-related variability
• Eliminate manual handling errors
• Increase repeatability and capacity for lifecycle sampling

DDU over the entire contents
For multi-dose devices, DDU assessment may require sampling across the inhaler’s full life (start, middle, end) to confirm consistent delivered dose throughout the contents and detect any lifecycle-related drift.

Technical characteristics / specifications

• Device category: Soft Mist Inhaler (SMI) / Aqueous Droplet Inhaler (ADI)
• Aerosol type: slow-moving aerosol cloud produced by active aqueous aerosolisation
• Typical DDU test flow rate (example): 28.3 L/min (constant flow)
• Testing approach: DDU testing aligned with MDI-style delivered dose collection and recovery across repeated actuations and device life
• Performance note: generally higher fine particle fraction compared with MDIs and DPIs
• Risk consideration: potential for microbial contamination in multi-dose liquid systems — control measures recommended