AeroChamber MAX* Valved Holding Chambers (VHCs) are designed for use with HFA formulations

The 1987 Montreal Protocol, an international treaty on “Substances that Deplete the Ozone Layer”, was drafted for the purpose of phasing out the commercial production of all ozone-depleting chlorofluorocarbon (CFC) propellants. Scientists have demonstrated that ultraviolet light converts CFCs to compounds that react with ozone, breaking down this protective layer in the atmosphere. As a result, hydrofluoroalkanes (HFA’s) have almost completely replaced CFC’s as the propellant used in pressurized metered dose inhaler (pMDI) inhalation aerosols, as the absence of chlorine in HFAs reduces it’s ozone-depleting activity to almost zero.

The physical characteristics of HFA formulations differ in a number of ways from their CFC counterparts. The reformulation of pMDIs with HFA-based propellants has resulted in changes to aerosol plume formation.¹  HFA formulations generally have a much higher propensity for static charge.

"Spacer devices designed for use with CFC type inhalers will not necessarily work as well with the new propellants. Electrostatic interactions between the formulation and spacer may differ and result in an altered performance that may compromise the safety or efficacy of the inhaler, or both. Only spacers specifically identified as suitable for a particular CFC-free inhaler should be used." ²

The AeroChamber MAX* VHC, the first transparent anti-static chamber, was designed especially for use with HFA formulations. The chamber is manufactured from StatBan*, a custom anti-static polymer that helps maximize aerosol suspension time, improving drug availability for patients who are not able to inhale and activate their pMDI concurrently. In addition, the 198mL volume chamber was specifically selected to accommodate the shorter, wider, HFA plumes.

The attached study summary documents the consistent performance of the AeroChamber MAX* VHC, in particular when used with HFA formulations.

⁽¹⁾ Using Holding Chambers With New HFA Drug Formulations. Jolyon Mitchell. Advance for Managers of Respiratory Care, June 2004, pp67-68.

⁽²⁾ Pharmacists – the scientists in the high street. Professor Tony Moffat. Science Committee of the Royal Pharmaceutical Society of Great Britain.

* trade-marks and registered trade-marks of Trudell Medical International

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