Experimental Evaluation of Dry Powder Inhalers during Inhalation 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 four dry powder inhalers under realistic inhalation and exhalation conditions. To simulate patients undergoing inhalation therapy, the active respiratory system model (xPULM™) was used. 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 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, while particles with the size of (>0.5 µm) are least influenced by deposition mechanisms. The fraction of exhaled particles ranges from 2.13% (HandiHaler®) over 2.94% (BreezHaler®), and 6.22% (Turbohaler®) to 10.24% (Ellipta®). These values are comparable to previously published studies. Furthermore, the mechanical upper airway model increases the resistance of the overall system and acts as a filter for larger particles (>3 µm). In conclusion, the xPULM™ active respiratory system model is a viable option for studying interactions of pharmaceutical aerosols and the respiratory tract regarding applicable deposition mechanisms. The model strives to support the reduction of animal experimentation in aerosol research and provides an alternative to experiments with human subjects.

Impact of treatment with direct-acting antivirals on anxiety and depression in chronic hepatitis C.

BACKGROUND AND AIM: Treatment of hepatitis C with direct-acting antiviral agents (DAA) has few side effects. Although pivotal studies suggested that DAA were safe in patients with psychiatric diseases who could not be treated with previous antiviral therapies, their effects on anxiety and depression have not yet been analysed in clinical practice. The aim of our study was to analyse anxiety and depression in the setting of DAA treatment in a clinical practice series. METHODS: All patients starting DAA treatment between November 1, 2014 and October 31, 2015 were eligible. Patients completed the Hospital Anxiety and Depression scale at different times during treatment. The results were plotted on line graphs and evaluated using a linear regression model with repeated measures. RESULTS: One hundred and forty-five patients were included (11% with major psychiatric disorders; 32% on psychiatric treatment). Sustained virologic response (SVR) was achieved in 97.3% of cases. Anxiety and depression measures did not differ between time points. No differences between patients on psychiatric treatment or with advanced fibrosis or cirrhosis were found at any time point analysed. CONCLUSION: DAA treatment had no impact on anxiety or depression during or after chronic hepatitis C infection treatment, even in high-risk patients with major psychiatric disorders.