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Technology
Direct to the target through inhalation
Asthma and COPD (chronically obstructive bronchial disease) are on the rise world-wide and require improvements and further development of the therapeutical possibilities. With a permeable surface area of from 80 to 100 m² between the alveolus wall and the blood circulation, the pulmonary alveolus represent an ideal target organ for the systematic administration of active substances.
Pulmonary administration of active substances in powder form
The trend in the new development of inhalation medications shows a clear increase of galenic formulations of active substances in powder form in comparison to inhalation spray. The powder is usually administered by a modern Inhaler (DPI = Dry Powder Inhaler or MDPI = Metered Dose Powder Inhaler). With MDPI-type Inhalers the powder supply is provided by blisters with up to 60 halos. This provides the patient with 60 therapeutical applications. The reservoir Inhaler supplies the inhalation powder through a powder chamber, which proportions the quantity of powder in the device.
The ideal Inhaler powder
A particle size between 1 µm and 5 µm is one of the basic requirements for substances in powder form to reach the alveoli. The high adhesive forces between the particles and their low fluidity make these substances extremely difficult to dose. This particularly applies if the single dose to be packaged lies in a range between 1 mg and 15 mg. With highly active substances, the active agents can be mixed with suitable carrier mediums. However, the dosing behavior of such mixtures also depends heavily on the micronization of the active agents. Furthermore, active agents are being increasingly administered as pure substances.
The appropriate dosing system
Conventional dosing systems for filling of hard gelatine capsules and vials, such as Dosator or tamping pin, do not provide the desired results for the micro-dosing of powder. The drum filler developed by Höfliger is ideally suitable for the dosing of powders with poor flowing capability. Equipped with a variable number of dosing bores, an effective dosing volume of between 1 mm³ and 100 mm³ per halo is provided. This allows ground lactose, a normal carrier material, to be filled in a range between 1 and 15 mg – with a standard deviation of between 1% and 3%. Comparable values can be achieved with pure micronized substances through the modification of the dosing system.
