Salbutamol relative lung and systemic bioavailability of large and small spacers

Salbutamol Easyhaler provides non-inferior relief of methacholine induced bronchoconstriction in comparison to Ventoline Evohaler with spacer: A randomized trial

BACKGROUND

Salbutamol is a cornerstone for relieving acute asthma symptoms, typically administered through a pressurized metered-dose inhaler (pMDI). Dry powder inhalers (DPIs) offer an alternative, but concerns exist whether DPIs provide an effective relief during an obstructive event.

OBJECTIVE

We aimed to show non-inferiority of Salbutamol Easyhaler DPI compared to pMDI with spacer in treating methacholine-induced bronchoconstriction. Applicability of Budesonide-formoterol Easyhaler DPI as a reliever was also assessed.

METHODS

This was a randomized, parallel-group trial in subjects sent to methacholine challenge (MC) test for asthma diagnostics. Participants with at least 20 % decrease in forced expiratory volume in 1 s (FEV1) were randomized to receive Salbutamol Easyhaler (2 × 200 μg), Ventoline Evohaler with spacer (4 × 100 μg) or Budesonide-formoterol Easyhaler (2 × 160/4.5 μg) as a reliever. The treatment was repeated if FEV1 did not recover to at least -10 % of baseline.

RESULTS

180 participants (69 % females, mean age 46 yrs [range 18-80], FEV1%pred 89.5 [62-142] %) completed the trial. Salbutamol Easyhaler was non-inferior to pMDI with spacer in acute relief of bronchoconstriction showing a -0.083 (95 % LCL -0.146) L FEV1 difference after the first dose and -0.032 (-0.071) L after the last dose. The differences in FEV1 between Budesonide-formoterol Easyhaler and Salbutamol pMDI with spacer were -0.163 (-0.225) L after the first and -0.092 (-0.131) L after the last dose.

CONCLUSION

The study confirms non-inferiority of Salbutamol Easyhaler to Ventoline Evohaler with spacer in relieving acute bronchoconstriction, making Easyhaler a sustainable and safe reliever for MC test and supports its use during asthma attacks.

Relative Lung and Systemic Bioavailability Along with Oropharyngeal Deposition of Salbutamol Post-Inhalation: A Pharmacokinetic Evaluation of Novel Inhaler Technique Training Gadgets

Background: Suboptimal use of pressurized metered dose inhaler (pMDI) remains a major barrier to inhaled therapy success. Verbal inhaler technique training (VT) fails to maintain patients' good pMDI use, thus training tools might help. Trainhaler^® (THR device) and Flo-Tone^® CR (FTCR device), two novel pMDI technique training tools, were evaluated and compared in terms of relative lung and systemic bioavailability and oropharyngeal deposition of salbutamol inhaled from Ventolin^® Evohaler^® (GlaxoSmithKline) either alone following THR or connected to FTCR. Methods: Sixteen healthy adults inhaled 2 × 100 μg salbutamol puffs (1 minute apart) from Ventolin using the THR device or FTCR device in a two-period, randomized crossover study. A 7-day washout separated THR and FTCR approaches. Immediately after each puff inhalation, each subject gargled with 20 mL water for oropharyngeal deposition determination. Urine samples were collected 0.5 hour (pre-inhalation) and 0.5, 1.0, and 2.0 hours post-inhalation. Urine was then pooled till 24-hour post-inhalation. The relative lung bioavailability (0- to 0.5-hour urinary salbutamol excretion-USAL0.5) and relative systemic bioavailability (0- to 24-hour urinary excretion of salbutamol and its metabolite-USALMET24) were determined. Results: The mean (standard deviation [SD]) USAL0.5 of the THR and FTCR groups was 5.70 (6.43) and 11.39 (9.67) μg, respectively. The mean (SD) oropharyngeal deposition was 11.11 (4.37) and 6.09 (1.89) μg, respectively. The THR and FTCR devices were statistically significantly different in USAL0.5 and oropharyngeal deposition (p < 0.001), whereas there was no statistically significant difference in USALMET24. Conclusion: The THR device and the FTCR device showed positive impact on inhaled pMDI delivery. Indeed, the FTCR device doubled the relative lung bioavailability and minimized the unwanted oropharyngeal deposition of inhaled salbutamol. In practice, these pMDI trainers would complement and maintain VT. Study Registration: The study was registered on the ISRCTN registry (Reference: ISRCTN88332465-06/12/2017 [Prospectively Registered]).

A 3D printed human upper respiratory tract model for particulate deposition profiling

Pulmonary route is the main route of drug delivery for patients with asthma and chronic obstructive pulmonary diseases, offering several advantages over the oral route. Determining the amount of drug deposited onto various parts of the respiratory tract allows for a good correlation to clinical efficacy of inhalation drug devices. However, current in vitro cascade impactors measure only the aerodynamic particle size distribution, which does not truly represent the in vivo deposition pattern in human respiratory tract. In this study, a human upper respiratory tract model was fabricated using a 3D printer and subsequently characterized for its dimensional accuracy, surface finishing and air leaking. The effects of using a spacer and/or various airflow rates were also investigated. To assess this in vitro model, the deposition pattern of a model drug, namely, salbutamol sulphate, was tested. The resultant deposition pattern of salbutamol sulphate from a metered dose inhaler at 15 L per minute with the spacer, showed no significant difference from that of a published radiological in vivo study performed in adult humans. In addition, it was also found that the deposition pattern of salbutamol at 35 L per minute was comparable to the results of another published study in human. This in vitro model, showing reasonable in vitro-in vivo correlation, may provide opportunities for personalized medicine in special populations or disease states.

Comparative pharmacokinetics of salbutamol inhaled from a pressurized metered dose inhaler either alone or connected to a newly enhanced spacer design

BACKGROUND

Coordination between actuation of a pressurized metered dose inhaler (pMDI) and inhalation is a critical manoeuvre that many patients fail to perform correctly. pMDIs connected to spacers do not require hand-lung coordination. This study evaluated the relative lung and systemic bioavailability and oropharyngeal deposition of salbutamol post-inhalation from Ventolin® Evohaler® (GlaxoSmithKline) either alone following verbal inhaler technique counselling (VC) or connected to a newly improved Able Spacer® (AS).

METHODS

In a two-period, randomized crossover study, 16 healthy adults inhaled 2 × 100 µg salbutamol puffs (1 min gap) from Ventolin using VC or AS. Immediately after each puff inhalation, each subject gargled with 20 mL water for oropharyngeal deposition (OD) determination. Urine samples were collected 0.5 h (pre-) and 0.5, 1.0 and 2.0 h post-inhalation. Urine was then pooled 2-24 h post-inhalation. The relative lung bioavailability (0-0.5 h urinary salbutamol excretion - USAL0.5) and systemic bioavailability (0-24 h urinary excretion of salbutamol and its metabolite - USALMET24) were determined. A one week washout separated VC and AS use.

RESULTS

The mean (SD) USAL0.5 of VC and AS was 5.36 (4.48) and 12.80 (10.83) µg, respectively. The mean (SD) OD was 11.35 (3.37) and 0.48 (0.30) µg, respectively. VC and AS were significantly different in USAL0.5 and OD (p<0.001). USALMET24 was comparable (p>0.05).

CONCLUSIONS

Compared with VC, AS doubled the inhaled salbutamol lung dose and minimised its precipitation in the oral cavity. The results suggest this inhalation aid can add therapeutic and safety benefits particularly in patients with continued pMDI technique issues despite repeated VC.

Real-Time Analysis of the Respiratory Flow Through a Valved Holding Chamber

Background: The ability of patients to take, correctly and regularly, aerosol treatments is a key for good control of asthma and chronic obstructive pulmonary disease. Devices that help to improve inhalation technique could train the patient to take their medication properly, reducing risk of exacerbations. In this study we evaluate a new device that by recording real-time respiratory flow into the valved holding chamber (VHC) mouthpiece, could be used to improve patient technique. Methods and Results: Using computational fluid dynamics analysis we demonstrated that compared to a mouthpiece with no flow probe, the presence of a probe modifies the flow profile and velocity regardless of the probe shape or position. During flow measurement using a SDP610 pressure sensor (Sensirion, Switzerland), all probes can accurately record adult and child respiratory patterns. Resistance was determined from the back pressure generated by the VHC with or without probes; and resistance was not impacted by the probes. Aerodynamic particle size distribution and drug delivery measurement were assessed using the United States Pharmacopeia throat model (Copley Scientific, UK), next generation impactor (NGI; Copley Scientific), and a breath simulator (BRS200; Copley Scientific). To test different formulations, these experiments were performed with fluticasone propionate (Flixotide^®; GSK, UK), salbutamol (Ventolin^®; GSK), and beclomethasone dipropionate (BDP) (QvarSpray^®; GSK). Depending on the molecule or the probe configuration, we noticed a decrease of the emitted doses, fine particle deposition, mass median aerodynamic diameter, but no significant change in the mass of drug delivered. A decrease in the fine particle fraction (FPF) was observed in most testing conditions. However, a slight increase was noticed for two conformations with BDP (round and close [Rc] and diamond and far [Df]) and salbutamol (Rc and round and far [Rf]). Conclusion: By inserting a flow probe directly into the mouthpiece of a VHC we could perform real-time analysis of respiratory flow during the VHC use without disturbing drug delivery, or increasing resistance.

Evaluation of asthma control, parents' quality of life and preference between AeroChamber Plus and AeroChamber Plus Flow-Vu spacers in young children with asthma

OBJECTIVE

The AeroChamber Plus (AC) valved holding chamber has been enhanced to include the Flow-Vu (FV) inspiratory flow indicator that provides visual inhalation feedback during use. We have investigated if FV alters asthma control and whether parents accept it.

METHODS

At visit 1, children with asthma, age 1-5 years, used an AC with their pressurised metered dose inhaler and 2 weeks later (visit 2) they were randomised to use either AC or FV. Subjects returned 6 (visit 3) and 12 (visit 4) weeks later. The Asthma Control (ACQ) and Paediatric Asthma Caregiver's Quality of Life (PACQLQ) questionnaires were scored at each visit, and their peak inhalation flow (PIF) when they used their spacer was measured.

RESULTS

Forty participants in each group completed the study. There was no difference in the ACQ scores from visits 2 to 4 between the two groups. The improvements in the PACQLQ scores were greater in the FV group (p = 0.029). The mean difference (95% confidence interval) for the change from visits 2 to 4 between FV and AC groups was 0.05 (-0.33, 0.43) and 0.39 (0.035, 0.737) for the ACQ and PACQLQ, respectively. Most parents preferred the FV (p < 0.001). There was no difference in the PIF rates at each visit and between the two spacers.

CONCLUSIONS

There was no change in asthma control of the young children but that of their parents improved. Parents preferred the FV and this could be related to their improved perception of their children's asthma control by better PACQLQ scores.

A valved holding chamber does not decrease the bronchodilator activity of budesonide-formoterol combination metered dose inhaler

OBJECTIVE

Spacers and valved holding chambers (VHCs) were developed to facilitate using pressurized metered dose inhaler (pMDI) by patients who could not coordinate the actions required for successful pMDI use. There is little in vivo evidence about how VHC may affect the bronchodilation from combination drugs in pMDI. This study was to determine the effect, if any, of VHC on the bronchodilating actions of the pMDI budesonide/formoterol combination.

METHODS

Sixteen adult asthmatic subjects with 15% or greater reversibility of forced expiratory volume in one second (FEV-1), 15 minutes after inhaling 180-360 μg of albuterol, participated. The study had a randomized crossover design with each subject using budesonide-formoterol pMDI as described in the product information one timeand on a second occasion using the pMDI with a VHC. Spirometry and impedance osscilometry were measured at baseline and repeatedly over a 12-hour period. This study was approved by IntegReview Institutional Review Board, Austin, TX, USA. The clinical trial number for this study was NCT 009-15538 (http://www.westernskymed.com).

RESULTS

The area under the curve of FEV-1, the FEV-1, and the fraction FEV-1/FVC was similar over the 12-hour time frame with both methods. Resistance was not different at any time point. In both procedures, the onset of bronchodilation occurred rapidly within 3 to 5 minutes.

CONCLUSIONS

In well-trained asthmatic subjects, both tested methods caused equivalent bronchodilation. This suggests a VHC itself has no deleterious effect on the bronchodilator activity in the combined drug. These results may not apply to patients who have coordination problems with the pMDI and further study is indicated.

Antibiotic and bronchodilator prescribing for acute bronchitis in the emergency department

BACKGROUND

Although the overuse of antibiotics and underuse of bronchodilators for treatment of acute bronchitis is well known, few studies have analyzed these trends in the emergency department (ED).

STUDY OBJECTIVES

To characterize the antibiotic and bronchodilator prescribing practices of physicians at two academic EDs in the diagnosis of acute bronchitis, and to identify factors that may or may not be associated with these practices.

METHODS

A computer database was searched retrospectively for all patients with an ED discharge diagnosis of acute bronchitis, and analyzed, looking at the frequency of antibiotic prescriptions, the class of antibiotic prescribed, and several other related factors including age, gender, chief complaint, duration of cough, and comorbid conditions.

RESULTS

During the study period, there were 836 cases of acute bronchitis in adults. Of these, 622 (74.0%) were prescribed antibiotics. Of those prescribed antibiotics, 480 (77.2%) were prescribed broad-spectrum antibiotics. Using multivariate analysis (odds ratio, 95% confidence interval), antibiotics were prescribed significantly more often in patients aged 50 years or older (1.7, 1.2-2.5) and in smokers (1.5, 1.0-2.2). Of patients without asthma, 346 (49.9%) were discharged without a bronchodilator, and 631 (91.1%) were discharged without a spacer device.

CONCLUSION

Antibiotics are over-prescribed in the ED for acute bronchitis, with broad-spectrum antibiotics making up the majority of the antibiotics prescribed. Age ≥50 years and smoking are associated with higher antibiotic prescribing rates.

The Bioavailability of Salbutamol in Urine via Volumatic and Nonvolumatic Valved Holding Chambers

Purpose

Pressurized metered dose inhalers are commonly used in patients with asthma. However, the need to coordinate inhalation with inhaler actuation means that they are not suitable for use per se. Valved holding chamber devices were developed to overcome some of the problems of pressurized metered dose inhalers. Several types of holding chambers of different sizes are available in Iran. This study was designed to compare the effects of 2 commonly used valved holding chambers (Asthm Yar and Dam Yar) in Iran on bioavailability of salbutamol spray and also spirometric parameters in asthmatic patients.

Methods

This was a comparative experimental crossover study. Patients with mild to moderate asthma were entered in this study. Lung function was assessed using a portable spirometer (Spirolab, Progetti, Italy). Spirometric parameters of forced expiratory flow (FEF)_50%, FEF_25–75%, peak expiratory flow (PEF), forced expiratory volume in the first second of expiration (FEV₁), forced vital capacity (FVC), and FEV₁/FVC were measured. Urinary concentration of salbutamol as an index of pulmonary bioavailability was assayed with high-performance liquid chromatography.

Results

Forty patients (25 women and 15 men) with the mean age of 43.10 ± 12.99 years were studied. Mean ± SD changes of spirometric parameters before and after using Asthm Yar were not significantly different from those of Dam Yar. The relative bioavailability after inhalation with Asthm Yar was significantly higher than after inhalation with Dam Yar (P = 0.002).

Conclusions

Although the results indicate that relative bioavailability to the lung after inhalation with Asthm Yar was significantly higher than after inhalation with Dam Yar, its clinical importance should be tested.

Solvation in hydrofluoroalkanes: how can ethanol help?

Objectives

The goal of this work was to evaluate the ability of ethanol mixed with hydrofluoroalkanes (HFAs) to improve solvation of moieties of relevance to pressurized metered-dose inhalers (pMDIs).

Methods

Chemical force microscopy was used to measure the adhesion force (Fad) between alkyl-based, ether-based and ester-based moieties (C8/C8, COC/COC and COOC/COOC interactions) in 2H,3H-perfluoropentane (HPFP)/ethanol mixtures. HPFP is a liquid that mimics propellant HFAs. The Fad results are thus a measure of solvation in HFAs. Johnson–Kendall–Roberts (JKR) theory was used to model the results.

Key findings

The Fad normalized by the tip radius of curvature (Fad/R) decreased upon the addition of ethanol, suggesting its ability to enhance the solvent environment. At 15% (v/v) ethanol, the Fad/R was reduced 34% for the alkyl, 63% for the ether, and down 67% for the ester tails. Thus, the solvation could be ranked as: ester &gt; ether &gt; alkyl. JKR theory was a reasonable model for the Fad/R.

Conclusions

Ethanol, within the concentration range of interest in commercial pMDIs, provided limited enhancement in solvation of alkyl moieties. On the other hand, the cosolvent significantly enhanced solvation of ether-based and ester-based moieties, thus suggesting its potential for formulations containing amphiphiles with such groups.

Choosing inhaler devices for people with asthma: current knowledge and outstanding research needs

Recommendations in asthma guidelines presuppose that practitioners have the evidence, information, knowledge, and tools to select inhaler devices appropriate for individual patients. Randomised controlled trials usually exclude patients with suboptimal inhaler technique. There is therefore little evidence on which to base inhaler selection in the real world, where patients often use their inhalers incorrectly. The lung deposition of inhaled drug varies according to inhaler device, drug particle size, inhalation technique, and pattern of inspiratory flow. Even with training, not all patients can use their inhalers correctly and maintain inhaler technique; patients may have inability to handle the inhaler, strong negative preferences, or natural breathing patterns that do not match their prescribed inhaler. Therefore, matching device to the patient may be a better course of action than increasing therapy or training and retraining a patient to use a specific inhaler device. Several research questions require answers to meet the goal of helping prescribers make a more informed choice of inhaler type. Is the level of drug deposition in the lungs a key determinant of clinical short- and long-term outcomes? What should be measured by a clinical tool designed to check inhaler technique and therefore help with device selection? If we have a tool to help in individualising inhaler choice, will we achieve better asthma outcomes? Do we have to refine inhaler device choice for each individual, or will we get better outcomes if we select our current best option in light of current knowledge and apply this on a population level?