DPI inhaler (dry-powder inhaler) is an inhaler, which is intended to deliver a drug in the form of dry powder to the lungs. It is taken for the treatment of asthma and asthmatic conditions. It is also used to treat other respiratory diseases. They are chronic obstructive pulmonary disease (COPD), emphysema and bronchitis. DPI inhalers, for example, such as inhalation insulin Afrezza, can also be used within the patients, suffering from diabetes mellitus.
DPI inhalers are considered to be an alternative kind of aerosol inhalers. They are also called metered-dose inhalers (MDIs), because when using DPI inhalers, the patients need to set the medication powder dosage. The medication can be produced in various forms. One of them is the form of capsules. In this case, manual filling of the inhaler with the medication is required. The drug can also be produced in the form of a proprietary from within an inhaler. After the medication has been loaded in the inhaler or after it has been actuated, the patient should place the mouthpiece of the inhaler in the mouth and take a deep slow breath in, thus making an inhalation. During the inhalation the patient should feel that the medication has reached the lower parts of the lungs. After the inhaling it is necessary to hold the breath for about 5-10 seconds.
Today, many devices of this kind are produced and the patients can choose among them. The patient should clearly know the required dosage, which is prescribed by the doctor. Usually, the dose for one breath can be less than several tens of milligrams. Large doses of the drug in the form of powder can provoke coughing.
The majority of DPI inhalers work in such a way that their use depends on the strength of the patient's breaths. The amount of powder that will enter the lungs during an inhalation depends on the strength of the patient's breaths in. If the breath is not deep, the powder will break into doses that are too small to get into the lungs and produce a positive effect from the medication. Thus, taking small doses of the drug will lead to an incomplete drug action and poor work of the whole device and the patient will not be able to obtain the desired result, as the drug will not relieve the symptoms of the disease. Thus, most DPI inhalers are designed so that, during the inhalation, minimal inspiratory effort is required for the proper use of the inhaler. Therefore, such inhalers are usually recommended to be used by the adults and older children.
It is known that there are some inhalers, which contain lactose. It is used to convey the parts of the active substance, which should be normal in order to achieve the desired result. Lactose helps with the exit of the drug powder from the inhaler during an inhalation. Lactose improves the consumption capacity of the drug powder at the time of manufacturing and using. It is also used as a filling substance.
It should be mentioned, that such lactose can harm the health of the people who are lactose intolerant. Some doctors do not allow taking lactose-containing DPIs in order not to develop the possibility of an emerging adverse reaction and hypersensitivity to the drug.
Method of Storage
The DPI inhaler should be stored at a maximum temperature of 25°C in a dry dark place and the 40-50% humidity. It should be stored in a small sealed package. It should be remembered that the effect of the powder on moisture impairs the ability of the device to spray the drug into a fine powder when inhaled.