In Vitro Drug Delivery of a Fixed-Dose Combination of Fluticasone Furoate/Umeclidinium/Vilanterol from a Dry Powder Inhaler

Utility of peak inspiratory flow measurement for dry powder inhaler use in chronic obstructive pulmonary disease

PURPOSE OF REVIEW

Every type of dry powder inhaler (DPI) device has its own intrinsic resistance. A patient's inspiratory effort produces a pressure drop that determines the inspiratory flow, depending on the inhaler's specific internal resistance. Optimal peak inspiratory flow (PIF) is needed for effective release of dry powder, disaggregation of drug-carrier agglomerates, and optimal deposition of respirable drug particles, particularly generation of a high fine-particle fraction to reach the small airways of the lungs. However, standardized recommendations for PIF measurements are lacking and instructions appeared vague in many instances.

RECENT FINDINGS

Suboptimal PIFs are common in outpatient chronic obstructive pulmonary disease (COPD) patients and during acute exacerbations of COPD, and are associated with increased healthcare resource utilization. There is significant variation in the results of studies which is in part related to different definitions of optimal flow rates, and considerable variation in how PIF is measured in clinical and real-life studies.

SUMMARY

Standardization of technique will facilitate comparisons among studies. Specific recommendations for PIF measurement have been proposed to standardize the process and better ensure accurate and reliable PIF values in clinical trials and clinical practice. Clinicians can then select and personalize the most appropriate inhaler for their patients and help them achieve the optimal PIF needed for effective drug dispersion.

Modeled small airways lung deposition of two fixed-dose triple therapy combinations assessed with in silico functional respiratory imaging

BACKGROUND

Small airways disease plays a key role in the pathogenesis of chronic obstructive pulmonary disease (COPD) and is a major cause of obstruction; therefore, it is a critical pharmacotherapy target. This study evaluated lung deposition of two inhaled corticosteroid (ICS)/long-acting β2-agonist/long-acting muscarinic antagonist single-inhaler triple therapies using in silico functional respiratory imaging (FRI). Deposition was assessed using real-world inhalation profiles simulating everyday use where optimal inhalation may be compromised.

METHODS

Three-dimensional airway models were produced from 20 patients with moderate-to-very severe COPD. Total, central, and regional small airways deposition as a percentage of delivered dose of budesonide/glycopyrronium/formoterol fumarate dihydrate (BGF) 160/7.2/5 µg per actuation and fluticasone furoate/umeclidinium/vilanterol (FF/UM/VI) 100/62.5/25 µg were evaluated using in silico FRI based on in vitro aerodynamic particle size distributions of each device. Simulations were performed using multiple inhalation profiles of varying durations and flow rates representing patterns suited for a pressurized metered-dose inhaler or dry-powder inhaler (four for BGF, two for FF/UM/VI, with one common profile). For the common profile, deposition for BGF versus FF/UM/VI was compared post-hoc using paired t-tests.

RESULTS

Across inhalation profiles, mean total lung deposition was consistently higher with BGF (47.0-54.1%) versus FF/UM/VI (20.8-22.7%) and for each treatment component, with greater deposition for BGF also seen in the central large airways. Mean regional small airways deposition was also greater across inhalation profiles with BGF (16.9-23.6%) versus FF/UM/VI (6.8-8.7%) and for each treatment component. For the common profile, total, central, and regional small airways deposition were significantly greater for BGF versus FF/UM/VI (nominal p < 0.001), overall and for treatment components; notably, regional small airways deposition of the ICS components was approximately five-fold greater with budesonide versus fluticasone furoate (16.1% vs. 3.3%).

CONCLUSIONS

BGF was associated with greater total, central, and small airways deposition for all components versus FF/UM/VI. Importantly, using an identical inhalation profile, there was an approximately five-fold difference in small airways deposition for the ICS components, with only a small percentage of the ICS from FF/UM/VI reaching the small airways. Further research is needed to understand if the enhanced delivery of BGF translates to clinical benefits.