The Inventive Decade

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

Figure 1 Technology drivers and "transformation" from conventional to new pulmonary delivery technologies.

was to follow or secure in the knowledge that at least in the short term CFC availability would not be an issue. However, at the start of the 1990s the renewed interest in the role CFCs were playing in the depletion of the ozone layer led to a plan to completely eliminate their manufacture and use [4]. The chemical industry responded by developing molecules with similar physicochemical properties to those of CFCs as replacements for refrigerants and blowing agents. The pharmaceutical industry responded by forming consortia to carry out the pulmonary toxicology on two of these new chemicals, propellants 134a and 227, to enable their use in metered-dose inhalers (IPACTI and IPACTII, respectively [5]). The industry's other response was to look for alternative technologies that could replace metered-dose inhalers. Between 1991 and 2000 over 1300 patents were filed in the pulmonary delivery technology area. These were roughly split between metered-dose inhalers and dry power technologies, with a small but significant number targeted at aqueous delivery. For comparison: in the previous decade, 1981-1990, only 240 patents were filed in those areas.

Coping with Asthma

Coping with Asthma

If you suffer with asthma, you will no doubt be familiar with the uncomfortable sensations as your bronchial tubes begin to narrow and your muscles around them start to tighten. A sticky mucus known as phlegm begins to produce and increase within your bronchial tubes and you begin to wheeze, cough and struggle to breathe.

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