Experimental Evaluation of Dry Powder Inhalers During In- and Exhalation Using a Model of the Human Respiratory System (xPULM™)

Dry powder inhalers are used by a large number of patients worldwide to treat respiratory diseases. The objective of this work is to experimentally investigate changes in aerosol particle diameter and particle number concentration of pharmaceutical aerosols generated by five dry powder inhalers under realistic inhalation and exhalation conditions. The active respiratory system model (xPULM™) was used as a model of the human respiratory system and to simulate a patient undergoing inhalation therapy. A mechanical upper airway model was developed, manufactured and introduced as a part of the xPULM™ to represent the human upper respiratory tract with high fidelity. Integration of optical aerosol spectrometry technique into the setup allowed for evaluation of pharmaceutical aerosols. The results show that the upper airway model increases the resistance of the overall system and act as a filter for bigger particles (>3 µm). Furthermore, there is a significant difference (p < 0.05) in mean particle diameter between inhaled and exhaled particles with the majority of the particles depositing in the lung. The minimum deposition is reached for particle size of 0.5 µm. The mean particle number concentrations exhaled are 2.94% (BreezHaler®), 2.66% (Diskus®), 10.24% (Ellipta®) 2.13% (HandiHaler®) and 6.22% (Turbohaler®). In conclusion, the xPULM™ active respiratory system model is a viable option for studying interactions of pharmaceutical aerosols and the respiratory tract in terms of applicable deposition mechanisms. The model can support the reduction of animal experimentation in aerosol research and provide an alternative to experiments with human subjects.

A Concise Overview on Recent Advances in Pharmaceutical Aerosols and Their Commercial Applications

Background: Localized drug delivery to the respiratory system has become an increasingly successful and essential treatment strategy for several pulmonary diseases, including asthma, chronic abstractive disease, pneumonia, bronchitis, and cystic fibrosis. The rising incidence of respiratory diseases is a significant factor driving the worldwide market for respiratory inhaler devices. Objective: The objective of this article is to present various aspects of pharmaceutical aerosols, including their types, components, fundamentals, in-process and finished product quality control tests based on pharmacopeial standards and specifications, and commercial utility considering the pharmaceutical aerosol dosage forms that have been patented from 2000 to 2020, along with a list of marketed pharmaceutical products. Method: Aerosol, collectively referred to as a pressurized device, operates by triggering an appropriate valve system with a continuous or metered dosage of tiny mist spray. It is used not only in the treatment of asthma and chronic obstructive pulmonary disease but also in the treatment of cancer, diabetes, migraine, angina pectoris, acute lung injury, bone disorders, tuberculosis, and many more. A multitude of different variables, including types and properties of propellants, active substances, containers, valves, actuators, spray patterns, valve crimping efficiency, and particle size of the aerosols, influence the therapeutic effectiveness of pharmaceutical aerosols. Conclusion: Based on the current findings, distinct characteristics such as the elimination of firstpass metabolism, quick drug absorption, ease of therapy termination, as well as a larger surface area have attributed to the success of pharmaceutical aerosols.

Experimental Evaluation of Dry Powder Inhalers During In- and Exhalation Using a Model of the Human Respiratory System (xPULM™)

Dry powder inhalers are used by a large number of patients worldwide to treat respiratory diseases. The objective of this work is to experimentally investigate changes in aerosol particle diameter and particle number concentration of pharmaceutical aerosols generated by five dry powder inhalers under realistic inhalation and exhalation conditions. The active respiratory system model (xPULM™) was used as a model of the human respiratory system and to simulate a patient undergoing inhalation therapy. A mechanical upper airway model was developed, manufactured and introduced as a part of the xPULM™ to represent the human upper respiratory tract with high fidelity. Integration of optical aerosol spectrometry technique into the setup allowed for evaluation of pharmaceutical aerosols. The results show that the upper airway model increases the resistance of the overall system and act as a filter for bigger particles (>3 µm). Furthermore, there is a significant difference (p < 0.05) in mean particle diameter between inhaled and exhaled particles with the majority of the particles depositing in the lung. The minimum deposition is reached for particle size of 0.5 µm. The mean particle number concentrations exhaled are 2.94% (BreezHaler®), 2.66% (Diskus®), 10.24% (Ellipta®) 2.13% (HandiHaler®) and 6.22% (Turbohaler®). In conclusion, the xPULM™ active respiratory system model is a viable option for studying interactions of pharmaceutical aerosols and the respiratory tract in terms of applicable deposition mechanisms. The model can support the reduction of animal experimentation in aerosol research and provide an alternative to experiments with human subjects.

Inhalotherapy in Noninvasive Ventilation

The use of non-invasive ventilation (NIV) has markedly increased over the last decades, and NIV has now become an important alternative to invasive ventilation and has gained popularity particularly as treatment option for patients with obstructive sleep apnea, chronic obstructive pulmonary disease (COPD), and acute respiratory failure. The most prominent forms of NIV are noninvasive positive pressure ventilation (NPPV) and the recently introduced high-flow nasal cannula (HFNC) therapy. Many patients who received NIV may also benefit from the administration of pharmaceutical aerosols, typically bronchodilators, which are best delivered without interrupting respiratory support. For example, nowadays, the use of NIV is considered the standard of care for some forms of acute respiratory failure such as COPD exacerbation and acute cardiogenic pulmonary edema. Patients with COPD exacerbation also benefit from inhaled bronchodilator therapy.