The Inhalation Characteristics of Patients When They Use Different Dry Powder Inhalers

Abstract

Background: The characteristics of each inhalation maneuver when patients use dry powder inhalers (DPIs) are important, because they control the quality of the emitted dose. Methods: We have measured the inhalation profiles of asthmatic children [CHILD; n¼16, mean forced expiratory volume in 1 sec (FEV 1 ) 79% predicted], asthmatic adults (ADULT; n¼53, mean predicted FEV 1 72%), and chronic obstructive pulmonary disease (COPD; n¼29, mean predicted FEV 1 42%) patients when they inhaled through an Aerolizer, Diskus, Turbuhaler, and Easyhaler using their ''real-life'' DPI inhalation technique. These are low-, medium-, medium/high-, and high-resistance DPIs, respectively. The inhalation flow against time was recorded to provide the peak inhalation flow (PIF; in L/min), the maximum pressure change (DP; in kPa), acceleration rates (ACCEL; in kPa/sec), time to maximum inhalation, the length of each inhalation (in sec), and the inhalation volume (IV; in liters) of each inhalation maneuver. Results: PIF, DP, and ACCEL values were consistent with the order of the inhaler's resistance. For each device, the inhalation characteristics were in the order ADULT > COPD > CHILD for PIF, DP, and ACCEL ( p < 0.001). The results showed a large variability in inhalation characteristics and demonstrate the advantages of DP and ACCEL rather than PIFs. Overall inhaled volumes were low, and only one patient achieved an IV > 4 L and DP > 4 kPa. Conclusion: The large variability of these inhalation characteristics and their range highlights that if inhalation profiles were used with compendial in vitro dose emission measurements, then the results would provide useful information about the dose patients inhale during routine use. The inhalation characteristics highlight that adults with asthma have greater inspiratory capacity than patients with COPD, whereas children with asthma have the lowest. The significance of the inhaled volume to empty doses from each device requires investigation.

Study of the Emitted Dose After Two Separate Inhalations at Different Inhalation Flow Rates and Volumes and an Assessment of Aerodynamic Characteristics of Indacaterol Onbrez Breezhaler® 150 and 300 μg

“…Patients with COPD have reduced inspiratory capacities together with low inhaled volumes (12), and so many use suboptimal inhalations when using DPIs which means that the dose they inhale is reduced.…”

“…The information that is most clinically relevant is to identify the type of dose emitted when low inhalation flows and inhaled volumes are used. This is very important for patients with COPD because these patients can only use low inhalation flows and low inhaled volumes (11,12). Therefore, the primary aim of this work was to investigate a range of inhalation flow rates (28.3, 60, 90 and 120 L/min) and volumes (500, 750, 1000, 1500 and 2000 mL) on the dose emission from 150 and 300 μg indacaterol Onbrez Breezhaler® (Novartis Pharmaceuticals Ltd., UK) using two separate inhalations.…”

Powder Particles and Technologies for Medicine Delivery to the Respiratory System: Challenges and Opportunities

“…The problem of L-R inhalers is that they are typically flowdependent, i.e. the mass and particle size distribution of the aerosol they release are significantly improved when flow increases (Weuthen T. et al, 2002;Azouz W. et al, 2015). Powder de-agglomeration is better at high airflow rates but at the same time the aerosol velocity at the inlet to the mouth becomes higher, which increases undesired drug deposition in the oro-pharynx.…”

Novel inhalation devices for treatment of chronic obstructive pulmonary disease

“…Теоретически при использовании подобных устройств для успешной ингаляции от пациента требуется большая скорость потока на вдохе -> 90 л / мин [12]. Развить такую скорость потока способны далеко не все больные ХОБЛ: объемная скорость вдоха у большинства из них находится в интервале 40-70 л / мин [5,13]. Для Аэролайзера низкое собственное сопротивление является недо статком, т. к. в этом ингаляторе доля частиц опти мального диаметра увеличивается пропорциональ но скорости воздушного потока.…”

“…Например, при ингаляции через Аэролайзер больной должен выполнить быстрый вдох общим объемом 4 л [4]. По результатам исследования у больных ХОБЛ показано, что такие пациенты при ингаляции через Аэролайзер делают вдох средним объемом только 1,7 л, при этом только 38 % паци ентов способны развить необходимую для успеш ной ингаляции скорость на вдохе [5]. В целом серьезные ошибки при вдохе через капсульные инга ляторы (Аэролайзер, ХандиХалер) совершают 45 % больных [2].…”