Inhalation pharmaceuticals demand exceptional analytical precision, especially when working with multiple active ingredients and sensitive propellant-based delivery systems. While carrying out routine batch-release testing for a complex inhalation product, Eurofins BPT Finland encountered a recurring and technically challenging assay issue in the combination inhaler’s analytics.
The project involved complex testing, e.g. NGI (APSD), delivered dose, API related substances, and assay. While most analyses consistently met specifications, the assay occasionally produced out-of-specification results. These deviations appeared sporadically: some replicates passed; others failed; and entire batches alternated between successful and unsuccessful outcomes.
There was no indication of an actual quality defect in the product, but the uncertainty created a risk of substantial delays to global supply. To investigate the issue thoroughly, teams across the laboratories and Quality Assurance collaborated closely with the client’s global development and manufacturing sites.
Joint troubleshooting sessions, reciprocal site visits, and even video recordings ensured full transparency throughout the process. A detailed GAP analysis across three international laboratories revealed that even tiny procedural and environmental variations could influence crystallisation behaviour and extraction efficiency. With the aerosol formulation, propellant behaviour during sample preparation proved particularly sensitive. Subtle differences in evaporation, humidity, and extraction handling between laboratories were potential contributors.
The root cause was identified to be a combination of several factors, and the findings enabled a robust update of the analytical method, adding clearer requirements for environmental conditions and harmonising all practical steps across laboratories. The case also highlighted the limitations of the original indirect method transfer approach.
Going forward, a direct method transfer will be implemented, with both laboratories analysing samples in parallel to verify full reproducibility. Today, the method performs reliably, and the client’s batches proceed without delay.
This case shows how inhalation expertise, strong collaboration, and systematic problem solving make Eurofins BPT Finland a trusted partner for complex analytical work. As a service laboratory, Eurofins BPT Finland consistently goes the extra mile, and the client expressed sincere appreciation for the support provided by the team’s specialists. For more information, visit: Eurofins BPT Finland