Inhaler

__NOTOC__ An inhaler or puffer is a medical device used for delivering medication into the body via the lungs. It is mainly used in the treatment of asthma and Chronic Obstructive Pulmonary Disease (COPD).

There are several different types of inhalers. The most common is the pressurized metered-dose inhaler ("MDI"). In MDIs, medication is most commonly stored in solution in a pressurized canister that contains a propellant, although it may also be a suspension ["Pharmaceutical Inhalation Aerosol Technology", ed. A. J. Hickey, 2nd edition, Marcel Dekker, NY, 2004.] . The MDI canister is attached to a plastic, hand-operated actuator. On activation, the metered-dose inhaler releases a fixed dose of medication in aerosol form. The correct procedure for using an MDI is to first fully exhale, place the mouth-piece end of the pump into the mouth, and having just started to inhale at a moderate rate, depress the canister to release the medicine. The aerosolized medication is drawn into the lungs by continuing to inhale deeply before holding the breath for 10 seconds to allow the aerosol to settle onto the walls of the bronchial and other airways of the lung.

To reduce deposition in the mouth and throat, and to reduce the need for precise synchronization of the start of inhalation with actuation of the device, MDIs are sometimes used with a complementary spacer or holding chamber device¹.

Besides the MDI, other types of inhalers¹ include dry powder inhalers (DPIs), which release a dose of medicine as a powder aerosol that is inhaled by the patient, and nebulizers, which instead supply the aerosol as a mist created from an aqueous formulation.

The largest manufacturers of inhalers are GlaxoSmithKline (makers of the Advair Discus (a DPI)), Merck, AstraZeneca (makers of Pulmicort and Symbicort) and Boehringer-Ingelheim (makers of Atrovent, Combivent, and Spiriva). BI, GSK, Merck, and AstraZeneca manufacture the medication being delivered via inhaler. However, 3M Drug Delivery Systems does some of the finished product manufacturing, as they are one of the leaders of MDI canisters, metering valves and other components.

Current Types of Inhalers by Delivery

* Metered-dose inhaler or MDI
* Dry Powder Inhaler or DPI
* Nebulizer

Current Types of Inhalers by Category

* Rescue Inhalers: Short-Acting Beta-2 Adrenergic Bronchodilator Inhalers
* Maintenance Inhalers: Long-Acting Adrenergic Bronchodilator Inhalers
* Maintenance Inhalers: Anticholinergic Bronchodilators in COPD
* Maintenance Inhalers: Corticosteroids
* Combination Inhalers: Corticosteroid with LongActing Beta-2 Adrenergic Agonist
* Combination Maintenance Inhaler: Anticholinergics with Short- Acting Beta-2 Adrenergic Agonists [ [http://www.redorbit.com/news/health/156919/changes_in_inhaler_devices_for_asthma_and_copd/index.html Changes in Inhaler Devices for Asthma And COPD - Health - RedOrbit ] ]

External links

* [http://http://www.mece.ualberta.ca/arla/tutorial.htm Basics aspects of inhaled pharmaceutical aerosols]
* [http://www.normanchigier.com/SpraySystemsusedinAerosolMedicationandTabletCoatings.html Recent advances in spray medication technology]
* [http://www.ourasthma.com Ourasthma.com] – a patient-oriented site with information on asthma inhalers.
* [http://zhenbo.9f.com/ Discrete simulation of powder dispersion in pharmaceutical aerosol inhalers]

References

*Patton, J., Breathing life into protein drugs - Inhalation of therapeutic macromolecules is a feasible, natural, more people-friendly, delivery system. Nature Biotechnology, 1998. 16(2): p. 141-143.