Metered dose inhalers patents

DeStefano G, Kelash-Cannavo LJ, inventors Boehringer Ingelheim Pharmaceuticals, Inc., U.S., assignee. Formulation for a Metered Dose Inhaler Using Hydrofluoroalkanes as Propellants. US Patent 2004184994, 2004. 

Bowman PA, Greenleaf D. Non-CFC metered dose inhalers the patent landscape. Int J Pharm 1999 186(l) 91-94. 

The modern pressurized metered dose inhaler (pMDI) was developed between 1955 and 1956. However, the pMDI had its roots in research carried out many years before.During the 1930s and 1940s, the discovery of liquefied propellants (chlorinated-fluorocarbons or freon propellants) such as CFC12, CFC114, CFCll, and CFC22 was a major step in the realization of a portable inhaler. However, the first pMDI was not invented until 1956, when the metering valve used in the device was developed and patented. ... 

The most significant developments in metered-dose inhaler technology to occur since the early 1990s have been the introduction of hydrofluoroalkane (HFA) systems as alternatives to chlorofluorocarbon (CFC) systems [174]. This has largely been caused by the link between the use of CFC systems and ozone depletion in the upper atmosphere [152,175]. Albuterol and beclomethasone have been reformulated in HFA products, but as yet the CFC products are still subject to an annually renewable medical exemption. The Food and Drug Administration has recently published its position on alternative propellant formulations, which should initiate the phase-out of CFCs [176]. In the meantime, a number of generic CFC products of albuterol have been manufactured. The opportunity for reformulation of products as they come of patent is likely to increase research and development in this area in the near future. New formulation opportunities will also arise from these developments, including solutions [177], micellar [178,179], and microemulsion [180]. 

Over the last 3 decades there have been two peaks in patent filings in the pulmonary delivery area (Fig. 2). Both of these seem to be related to the work of Molina and Rowlands [3], and both seem to have been driven by the threat that CFCs would be banned and would no longer be available for use in metered-dose inhalers. The first of these occurred in early 1970s. In the U.S. this first scare resulted in reformulation efforts for consumer products, but after a brief flurry of pulmonary patents the pharmaceutical industry settled back, oblivious to what... 

P. Modi patented a mixed micellar for administering insulin to the buccal mucosa using a metered dose inhaler.52 The formulation includes a micellar proteinic pharmaceutical agent, lauryl sulphate, salicylate, edetate, and at least one absorption-enhancing compound such as lecithin, hyaluronic acid, glycolic acid, oleic acid, linolenic acid, or glycerin. 

Figure 2 Pulmonary technology patent filings per year related to either metered-dose or dry powder inhalers. (Data generated using Aurigin Inc. patent search engine. Numbers may be slight overestimates of total related patents, due to restriction in search terms.)...

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