Evaluation of pMDI valve performance through equilibration at refrigerated and ambient conditions




Pressurised Metered Dose Inhalers (pMDIs) are used as a device for delivering a measured amount of a known substance in a measured quantity with consistent performance. Allowing the valves and cans which make up the primary container-closure system time to equilibrate is a standard practice across the pharmaceutical industry specifically, pMDI  medicine manufacturers. The time that a container-closure system is under quarantine allowing valve equilibration is typically 14 days.

This study investigated the functionality of a container-closure system at given timepoints across numerous conditions, specifically, the storage of temperature sensitive formulations which require a period of refrigeration immediately post-manufacture. The conditions investigated included refrigerated, 2 – 8 °C and ambient, 25 °C ± 2 °C / 60% RH ± 5% RH. Two valves, from different valve manufacturers, Aptar Pharma and Consort Medical, were investigated to analyse the performance of both valves under the conditions discussed.

It was found, under the conditions investigated that the optimal interconnection of the container-closure system is formed almost immediately post-manufacture. No single container-closure system tested exceeded the USP limits for leak rate (mg/yr). The study showed that both valves undergo equilibration at both refrigerated and ambient conditions. Both valves tested performed satisfactorily delivering a consistent and within limit mean actuation weight for all therapeutic doses i.e. Actuation 2 – 6. This study could provide the impetus for evaluating current quarantine periods for the pMDI manufacturing industry, for formulations which require refrigerated storage conditions pre-patient dispensing.

Key Message

The valves discussed within this report have been tested for their suitability for use in pMDI products which require storage at refrigerated temperatures i.e. 2 – 8 °C. From the data produced, it is concluded that the valves from both manufacturers are adequate for use following equilibration at cold conditions.