Inhalable insulin was available from September 2006 to October 2007 in the United States as a new method of delivering insulin, a drug used in the treatment of diabetes, to the body. After the withdrawal of the only inhalable formulation, all currently available insulin formulations are administered by subcutaneous or intravenous injection.

The first such product to be marketed was Exubera, a powdered form of recombinant human insulin, delivered through an inhaler into the lungs where it is absorbed.

Once it has been absorbed, it begins working within the body over the next few hours. Diabetics still need to take a longer acting basal insulin by injection. - cost of £1,100 per person per year.

A systematic review concluded that inhaled insulin "appears to be as effective, but no better than injected short-acting insulin. The additional cost is so much more that it is unlikely to be cost-effective." In October 2007, Pfizer announced that it would be discontinuing the production and sale of Exubera due to poor sales. Several other companies are developing inhaled forms of the drug to reduce the need for daily injections among diabetics.

History

Insulin was introduced by Banting and Best in 1921 as an injectable agent. German researchers first introduced the idea of inhalable insulin in 1924. Years of failure followed until scientists realized they might be able to use new technologies to turn insulin into a concentrated powder with particles sized for inhalation.

This technology was developed so that the inhaled insulin can effectively reach the lung capillaries where it is absorbed.

Nektar Therapeutics of San Carlos, California developed this technology that paved the way for pharmaceutical companies to begin testing and formulating inhalable insulin. Once concrete methods were developed, human tests began in the late 1990s. In January 2006, the FDA approved the use of Exubera which is a form of inhalable insulin developed by Pfizer.

Approval and competing drug development

Exubera is the brand name of first formulation of inhalable insulin to receive the US Food and Drug Administration (FDA) approval. It is manufactured by Pfizer in collaboration with Nektar Therapeutics and is licensed for use by both type 1 and type 2 diabetics. However in the UK its use in under the National Health Service "should not be recommended because it could not be proven to be more clinically or cost effective than existing treatments", - cost of £1,100 per person per year. except under special circumstances.