90 research outputs found
Biophysical model to predict lung delivery from a dual bronchodilator dry-powder inhaler
A biophysical lung model was designed to predict inhaled drug deposition in patients with obstructive airway disease, and quantitatively investigate sources of deposition variability. Different mouth-throat anatomies at varying simulated inhalation flows were used to calculate the lung dose of indacaterol/glycopyrronium [IND/GLY] 110/50 µg (QVA149) from the dry-powder inhaler Breezhaler®. Sources of variability in lung dose were studied using computational fluid dynamics, supported by aerosol particle sizing measurements, particle image velocimetry and computed tomography. Anatomical differences in mouth-throat geometries were identified as a major source of inter-subject variability in lung deposition. Lung dose was similar across inhalation flows of 30–120 L/min with a slight drop in calculated delivery at high inspiratory flows. Delivery was relatively unaffected by inhaler inclination angle. The delivered lung dose of the fixed-dose combination IND/GLY matched well with corresponding monotherapy doses. This biophysical model indicates low extra-thoracic drug loss and consistent lung delivery of IND/GLY, independent of inhalation flows. This is an important finding for patients across various ages and lung disease severities. The model provides a quantitative, mechanistic simulation of inhaled therapies that could provide a test system for estimating drug delivery to the lung and complement traditional clinical studies
Optimization and Dose Estimation of Aerosol Delivery to Non-Human Primates
Background: In pre-clinical animal studies, the uniformity of dosing across subjects and routes of administration is a crucial requirement. In preparation for a study in which aerosolized live-attenuated measles virus vaccine was administered to cynomolgus monkeys (Macaca fascicularis) by inhalation, we assessed the percentage of a nebulized dose inhaled under varying conditions.
Methods: Drug delivery varies with breathing parameters. Therefore we determined macaque breathing patterns (tidal volume, breathing frequency, and inspiratory to expiratory (I:E) ratio) across a range of 3.3-6.5 kg body weight, using a pediatric pneumotachometer interfaced either with an endotracheal tube or a facemask. Subsequently, these breathing patterns were reproduced using a breathing simulator attached to a filter to collect the inhaled dose. Albuterol was nebulized using a vibrating mesh nebulizer and the percentage inhaled dose was determined by extraction of drug from the filter and subsequent quantification.
Results: Tidal volumes ranged from 24 to 46 mL, breathing frequencies from 19 to 31 breaths per minute and I: E ratios from 0.7 to 1.6. A small pediatric resuscitation mask was identified as the best fitting interface between animal and pneumotachometer. The average efficiency of inhaled dose delivery was 32.1% (standard deviation 7.5, range 24%-48%), with variation in tidal volumes as the most important determinant.
Conclusions: Studies in non-human primates aimed at comparing aerosol delivery with other routes of administration should take both the inter-subject variation and relatively low efficiency of delivery to these low body weight mammals into account
A Handling Study to Assess the Use of the Respimat® Soft Mist™ Inhaler in Children Aged 4–12 Years
Asthma control in patients receiving inhaled corticosteroid and long-acting beta2-agonist fixed combinations. A real-life study comparing dry powder inhalers and a pressurized metered dose inhaler extrafine formulation
<p>Abstract</p> <p>Background</p> <p>Although patients have more problems using metered dose inhalers, clinical comparisons suggest they provide similar control to dry powder inhalers. Using real-life situations this study was designed to evaluate asthma control in outpatients with moderate to severe persistent asthma and to compare efficacy of fixed combinations of inhaled corticosteroids (ICS) and long acting beta-agonists (LABA).</p> <p>Methods</p> <p>This real-life study had a cross-sectional design. Patients using fixed combinations of ICS and LABA had their asthma control and spirometry assessed during regular visits.</p> <p>Results</p> <p>111 patients were analyzed: 53 (47.7%) received maintenance therapy of extrafine beclomethasone-formoterol (BDP/F) pressurized metered dose inhaler (pMDI), 25 (22.5%) fluticasone-salmeterol (FP/S) dry powder inhaler (DPI), and 33 (29.7%) budesonide-formoterol (BUD/F) DPI. Severity of asthma at time of diagnosis, assessed by the treating physician, was comparable among groups. Asthma control was achieved by 45.9% of patients; 38.7% were partially controlled and 15.3% were uncontrolled. In the extrafine BDF/F group, asthma control total score, daytime symptom score and rescue medication use score were significantly better than those using fixed DPI combinations (5.8 ± 6.2 vs. 8.5 ± 6.8; 1.4 ± 1.8 vs. 2.3 ± 2.1; 1.8 ± 2.2 vs. 2.6 ± 2.2; p = 0.0160; p = 0.012 and p = 0.025, respectively) and the mean daily ICS dose were significantly lower.</p> <p>Conclusions</p> <p>pMDI extrafine BDP/F combination demonstrated better asthma control compared to DPIs formulated with larger particles. This could be due to the improved lung deposition of the dose or less reliance on the optimal inhalation technique or both.</p
Aerosolized Delivery of Antifungal Agents
Pulmonary infections caused by Aspergillus species are associated with significant morbidity and mortality in immunocompromised patients. Although the treatment of pulmonary fungal infections requires the use of systemic agents, aerosolized delivery is an attractive option in prevention because the drug can concentrate locally at the site of infection with minimal systemic exposure. Current clinical evidence for the use of aerosolized delivery in preventing fungal infections is limited to amphotericin B products, although itraconazole, voriconazole, and caspofungin are under investigation. Based on conflicting results from clinical trials that evaluated various amphotericin B formulations, the routine use of aerosolized delivery cannot be recommended. Further research with well-designed clinical trials is necessary to elucidate the therapeutic role and risks associated with aerosolized delivery of antifungal agents. This article provides an overview of aerosolized delivery systems, the intrapulmonary pharmacokinetic properties of aerosolized antifungal agents, and key findings from clinical studies
Mucociliary and long-term particle clearance in airways of patients with immotile cilia
Spherical monodisperse ferromagnetic iron oxide particles of 1.9 μm geometric and 4.2 μm aerodynamic diameter were inhaled by seven patients with primary ciliary dyskinesia (PCD) using the shallow bolus technique, and compared to 13 healthy non-smokers (NS) from a previous study. The bolus penetration front depth was limiting to the phase1 dead space volume. In PCD patients deposition was 58+/-8 % after 8 s breath holding time. Particle retention was measured by the magnetopneumographic method over a period of nine months. Particle clearance from the airways showed a fast and a slow phase. In PCD patients airway clearance was retarded and prolonged, 42+/-12 % followed the fast phase with a mean half time of 16.8+/-8.6 hours. The remaining fraction was cleared slowly with a half time of 121+/-25 days. In healthy NS 49+/-9 % of particles were cleared in the fast phase with a mean half time of 3.0+/-1.6 hours, characteristic of an intact mucociliary clearance. There was no difference in the slow clearance phase between PCD patients and healthy NS. Despite non-functioning cilia the effectiveness of airway clearance in PCD patients is comparable to healthy NS, with a prolonged kinetics of one week, which may primarily reflect the effectiveness of cough clearance. This prolonged airway clearance allows longer residence times of bacteria and viruses in the airways and may be one reason for increased frequency of infections in PCD patients
Improper inhaler technique is associated with poor asthma control and frequent emergency department visits
Performance Characteristics of Breezhaler((R)) and Aerolizer((R)) in the Real-World Setting
The evaluation of errors in use with different inhaler devices is challenging to quantify as there are a number of definitions of critical and non-critical errors with respect to inhaler use; in addition, performance characteristics of the device, such as airflow resistance, can also influence effective use in the real-world setting. Repeated observations and checking/correcting inhaler use are essential to optimise clinical effectiveness of inhaled therapy in patients. Breezhaler® is a single unit-dose dry powder inhaler used in chronic obstructive pulmonary disease and in asthma (budesonide) that has low airflow resistance, making it easier for patients of varying disease severities to achieve the inhalation flow rate required for lung deposition of treatment. Similar to Breezhaler®, the Aerolizer® is a single unit-dose dry powder inhaler used in asthma management with low airflow resistance. Studies have shown relatively low rates of critical errors with Breezhaler® and Aerolizer®, with similarities in the critical errors reported; these data on critical errors together with similarities in the usability of Breezhaler® and Aerolizer® further support the functional similarity between the two devices in both asthma and chronic obstructive pulmonary disease. Breezhaler® also has patient-feedback features, including use of a transparent drug capsule that can be checked after inhalation to see it is empty. The low resistance of the dose-confirming Breezhaler® results in less inspiratory effort being required by patients for its effective use, which allows the device to be used effectively across a wide age range of patients and disease severities
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