title: Twenty years of HFA pMDI patents: facts and perspectives.
abstract: OBJECTIVE
  Over the past 20 years, the inhalation drug delivery industry has undergone a quiet revolution after the phasing out of the chlorofluorocarbon propellants used to formulate pressure-metered dose inhalers (pMDIs). This review looks back to the creative landscape of those 20 years through a study of patent application trends. To this end, an analysis of the hydrofluoroalkane pMDIs patent landscape was undertaken.
  
  
  METHODS
  A statistical analysis demonstrates that 20 years after the introduction of hydrofluoroalkanes in the inhalation delivery field, the original patent applications are coming to the end of their legal life.
  
  
  RESULTS
  Detailed analysis revealed that, from a total of 971 of the patents identified, up to 2.3% will expire within the next 5 years, rising to up to 7.3% in the next 10 years. The UK and USA were the main patent destinations and locations of inventive activity, as measured by patent filing location. Interestingly, the UK was the first destination and location of inventive activity in Europe, largely due to the activity of GlaxoSmithKline, followed by Italy, thanks to the work of Trinity-Chiesi. The analysis also showed that patent assignees are not always major pharmaceutical companies, with suppliers of propellants, as well as companies without major inhalation activity (such as Novadel), making substantial contributions to the landscape.
  
  
  CONCLUSIONS
  These developments may have a significant impact on innovation trends and key company activity around novel pMDI formulations, in particular for generics manufacturers.
authors.affiliation: Faculty of Pharmacy and Pharmaceutical Sciences, Monash University, Parkville, VIC, Australia. philippe.rogueda@monash.edu
authors.forename: Philippe
authors.initials: P
authors.lastname: Rogueda
authors.forename: Arthur
authors.initials: A
authors.lastname: Lallement
authors.forename: Daniela
authors.initials: D
authors.lastname: Traini
authors.forename: Ilian
authors.initials: I
authors.lastname: Iliev
authors.forename: Paul M
authors.initials: PM
authors.lastname: Young
mesh_terms: D000280:Administration, Inhalation; D000335:Aerosol Propellants / Q000737:chemistry*; D000473:Alkanes / Q000737:chemistry; D000818:Animals; D016503:Drug Delivery Systems / Q000266:history* / Q000639:trends; D004345:Drug Industry / Q000639:trends; D005466:Fluorocarbons / Q000737:chemistry; D049673:History, 20th Century; D049674:History, 21st Century; D006801:Humans; D006846:Hydrocarbons, Halogenated / Q000737:chemistry; D018973:Intellectual Property; D036501:Metered Dose Inhalers / Q000266:history* / Q000639:trends; D010330:Patents as Topic; D013678:Technology, Pharmaceutical / Q000639:trends
chemical_list: D000335:Aerosol Propellants; D000473:Alkanes; D005466:Fluorocarbons; D006846:Hydrocarbons, Halogenated