The agency has decided to remove the "essential use" designation from the epinephrine CFC propelled inhalers based on the "tentative conclusion" that there were "no substantial technical barriers to formulating epinephrine as a product that does not release CFCs" .
The move follows the March 2005 announcement by the FDA that it would phase out CFC propelled albuterol metered dose inhalers by December 31 next year with the conversion to hydrofluoroalkanes (HFA) propellants.
Previously, such CFC inhalers containing epinephrine and albuterol had been exempted from the international agreement to save the ozone layer, the Montreal Protocol, on the basis of medical necessity.
All other CFCs in consumer aerosols have been generally banned since 1978 to reduce the ozone-depleting effects the chemicals have.
Under the FDA's proposed rule, epinephrine metered dose inhalers containing CFCs, used for the temporary relief of occasional symptoms of mild asthma, would be removed from the market by the end of 2010.
Only Wyeth Consumer Healthcare and Armstrong Pharmaceuticals, a subsidiary of Amphastar Pharmaceuticals, manufacture epinephrine CFC propelled inhalers - Primatene Mist and Epinephrine Mist respectively - which have been available as over-the-counter (OTC) asthma treatments in the US since the 1960s.
With no epinephrine HFA metered dose inhaler or dry powder inhaler alternatives currently available on the market, reformulation or removal from the market are the two options faced by the manufacturers.
If completely removed from the market, patients would be forced to use prescription-only alternatives.
"The most direct alternative would be albuterol HFA inhalers," an FDA spokesman told US-PharmaTechnologist.com.
But while being an adrenergic bronchodilator like epinephrine, albuterol was not therapeutically equivalent and was a prescription-only drug, the spokesman said.
Wyeth Consumer Healthcare, which has some three million US users of its Primatene Mist, would remove the product from shelves as of December 31, 2010, Wyeth spokesman Fran Sullivan told US-PharmaTechnologist.com.
The company was not looking for other alternatives, or different types of inhalers and would not reformulate Primatene Mist, Sullivan said.
Despite the FDA's view on there being "no substantial technical barriers" , Sullivan said, according to Wyeth the reformulation of epinephrine posed "serious technical challenges". "
Wyeth evaluated several options for reformulating Primatene Mist - for a variety of reasons this reformulation proved untenable.
This fact, combined with the medical community's position on OTC treatment of asthma lead us to the conclusion not to reformulate.
Many physicians believe there are superior treatments for managing asthma, which are available by prescription."
A spokesman from Armstrong was unavailable for comment at time of publishing.
A 60-day public comment period will commence following the publication of the proposed rule in the Federal Register, and an open public meeting on the essential use of epinephrine will be held on a date yet to be confirmed.