CFC-free compliance a "blessing in disguise"

As the December 31 deadline for the removal of CFC albuterol inhalers in the US approaches, a new report by Kalorama Information forecasts big changes in the global $36bn (€26bn) a year respiratory products market.

The study, which was published earlier this week, predicts that removing inhalers that use chloro-fluoro carbon (CFC)-based propellants from the shelves will both spur innovation and drive a 10 per cent market expansion.

The report asserts that respiratory equipment suppliers have been teaming up to install new manufacturing capacity to prepare for the phase out. According to author Joe Constance, the effort and money spent “could be a blessing in disguise.”

Constance explained that because the ban has been brought in over an extended period, “[drugmakers] have had sufficient time to take the necessary steps to shift towards hydrofluoroalkane (HFA)-based products.”

To date only three branded HFA albuterol products have been approved by the Food and Drug Administration (FDA): Teva's Proair; Schering Plough's Proventil; and GlaxoSmithKline's Ventolin. These drugs look set to dominate the market for the foreseeable future.

Late last year, Datamonitor predicted that Teva's ProAir was most likely to reap the benefits of the lack of competition due to its favourable price compared with other HFA products.

In addition, no generic HFA has so far been approved in the US, despite the fact that branded versions will begin to lose patent protection in 2010. A 2007 Decision Resources survey suggested that, while the non-CFC market is a considerable opportunity, generics firms have been slow to develop products due to the relative complexity of their manufacture.

Manufacturing complexity

In his paper "The CFC to HFA transition and its impact on pulmonary drug development," Chet Leach of the Lovelace Respiratory Research Institute, discussed some of these challenges associated with developing HFA-based inhalers.

He explained that problems ranging from the poor compatibility of surfactants with HFA to the difficulties associated with sealant technologies have hampered development efforts.

Dr Leach added that because the thermodynamic properties of CFCs and HFAs differ considerably, the design of the inhaler, known as the boot, is critical in ensuring both the correct particle diameter and size and shape of the delivery plume.

He also said that manufacturing facilities need significant modification to be capable of safely producing HFA-based inhalers, particularly as a result of the use of flammable co-solvents such as ethanol.