Inhalation devices for pulmonary administration are only as good as the patient can handle them. Regular training and error checking are therefore essential. It is also important to find the right device for each patient. Medical aerosols are dust or mist aerosols that arise immediately before or during inhalation. Only particles between 1 and 5 µm in size are relevant for the treatment of respiratory diseases. In order for these to be deposited “in the right place”, namely in the deep airways, the patient must use the correct breathing technique.
The generation of mist aerosols requires slow and deep inhalation. With powder inhalers, on the other hand, the patient has to inhale vigorously so that the micronized active ingredient particles are detached from their carrier substances by a high inhalation flow. A subsequent pause of five to ten seconds favors the sedimentation and diffusion of the particles.
Inhalers and Portable Nebulizers
New inhalers, propellant-powered metered dose aerosols and powder inhalers, were introduced to the market. The most innovative development was with the nebulizers with the introduction of portable nebulizers (https://truneb.com/). In contrast to the usual electrical devices (compressed air-operated compressors or ultrasonic nebulizers), the soft inhaler works purely mechanically and generates a relatively uniform, affordable range of particle sizes. The handy device is easy to use, inhalation only takes a few seconds. There is no cold stimulus. The filling level of the cartridge can easily be read off. The downside with many advantages: the system is only available for a fixed combination of fenoterol and ipratropium bromide.
The CFC ban has clearly promoted the development of metered dose inhalers, because the switch to HFC propellants required readjustment of the entire system. It turned out to be beneficial that some active ingredients are soluble in norflurane: the particles are smaller, the size spectrum is narrower and the impact losses are lower. The undesired deposition in the oropharynx decreases, the desired endobronchial deposition increases. That means: more effect, fewer side effects.
The CFC ban in powder inhalers has given a boost to innovation. When the patient breathes in, micronized medicinal powder, which is bound to lactose as a carrier, is swirled into dust aerosols. A distinction is made between refillable systems that can be loaded with hard gelatine capsules, double-foil discs or powder cartridges and non-refillable devices.
With the variety of devices available, the patient must be given thorough training. For this, the multipliers would also have to train and acquire solid knowledge of the dosage forms. As long as there is still no optimal inhaler for all patients, technical innovations are necessary to improve the effectiveness and tolerability of pulmonary administration.