Concept review of dry powder inhalers: correct interpretation of published data

Bacteriophage endolysin powders for inhaled delivery against pulmonary infections

Endolysins are bacteriophage-encoded enzymatic proteins that have great potential to treat multidrug-resistant bacterial infections. Bacteriophage endolysins Cpl-1 and ClyJ-3 have shown promising antimicrobial activity against Streptococcus pneumoniae, which causes pneumonia in humans. This is the first study to investigate the feasibility of spray-dried endolysins Cpl-1 and ClyJ-3 with excipients to produce inhalable powders. The two endolysins were individually tested with leucine and sugar (lactose or trehalose) for spray drying method followed by characterization of biological and physico-chemical properties. A complete loss of ClyJ-3 bioactivity was observed after atomization of the liquid feed solution（before the drying process）, while Cpl-1 maintained its bioactivity in the spray-dried powders. Cpl-1 formulations containing leucine with lactose or trehalose showed promising physico-chemical properties (particle size, crystallinity, hygroscopicity, etc.) and aerosol performances (fine particle fraction values above 65%). The results indicated that endolysin Cpl-1 can be formulated as spray dried powders suitable for inhaled delivery to the lungs for the potential treatment of pulmonary infections.

Comparison of peak inspiratory flow rate via the Breezhaler®, Ellipta® and HandiHaler® dry powder inhalers in patients with moderate to very severe COPD: a randomized cross-over trial

BACKGROUND

The chronic and progressive nature of chronic obstructive pulmonary disease (COPD) requires self-administration of inhaled medication. Dry powder inhalers (DPIs) are increasingly being used for inhalation therapy in COPD. Important considerations when selecting DPIs include inhalation effort required and flow rates achieved by patients. Here, we present the comparison of the peak inspiratory flow rate (PIF) values achieved by COPD patients, with moderate to very severe airflow limitation, through the Breezhaler®, the Ellipta® and the HandiHaler® inhalers. The effects of disease severity, age and gender on PIF rate were also evaluated.

METHODS

This randomized, open-label, multicenter, cross-over, Phase IV study recruited patients with moderate to very severe airflow limitation (Global Initiative for Obstructive Lung Disease 2014 strategy), aged ≥40 years and having a smoking history of ≥10 pack years. No active drug or placebo was administered during the study. The inhalation profiles were recorded using inhalers fitted with a pressure tap and transducer at the wall of the mouthpiece. For each patient, the inhalation with the highest PIF value, out of three replicate inhalations per device, was selected for analysis. A paired t-test was performed to compare mean PIFs between each combination of devices.

RESULTS

In total, 97 COPD patients were enrolled and completed the study. The highest mean PIF value (L/min ± SE) was observed with the Breezhaler® (108 ± 23), followed by the Ellipta® (78 ± 15) and the HandiHaler® (49 ± 9) inhalers and the lowest mean pressure drop values were recorded with the Breezhaler® inhaler, followed by the Ellipta® inhaler and the HandiHaler® inhaler, in the overall patient population. A similar trend was consistently observed in patients across all subgroups of COPD severity, within all age groups and for both genders.

CONCLUSIONS

Patients with COPD were able to inhale with the least inspiratory effort and generate the highest mean PIF value through the Breezhaler® inhaler when compared with the Ellipta® and the HandiHaler® inhalers. These results were similar irrespective of patients' COPD severity, age or gender.

TRIAL REGISTRATION

The trial was registered with ClinicalTrials.gov NCT02596009 on 4 November 2015.

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

Onbrez Breezhaler® is a low-resistance capsule-based device that was developed to deliver indacaterol maleate. The study was designed to investigate the effects of both maximum flow rate (MIF) and inhalation volume (Vin) on the dose emission of indacaterol 150 and 300 μg dose strengths after one and two inhalations using dose unit sampling apparatus (DUSA) as well as to study the aerodynamic characteristics of indacaterol Breezhaler® using the Andersen cascade impactor (ACI) at a different set of MIF and Vin. Indacaterol 150 and 300 μg contain equal amounts of lactose per carrier. However, 150 μg has the smallest carrier size. The particle size distribution (PSD) of indacaterol DPI formulations 150 and 300 μg showed that the density of fine particles increased with the increase of the primary pressure. For both strengths (150 μg and 300 μg), ED1 increased and ED2 decreased when the inhalation flow rate and inhaled volume increased. The reduction in ED1 and subsequent increase in ED2 was such that when the Vin is greater than 1 L, then 60 L/min could be regarded as the minimum MIF. The Breezhaler was effective in producing respirable particles with an MMAD ≤5 μm irrespective of the inhalation flow rate, but the mass fraction of particles with an aerodynamic diameter <3 μm is more pronounced between 60 and 90 L/min. The dose emission of indacaterol was comparable for both dose strengths 150 and 300 μg. These in vitro results suggest that a minimum MIF of 60 L/min is required during routine use of Onbrez Breezhaler®, and confirm the good practice to make two separate inhalations from the same dose.