Effects of the mouthpiece and chamber of Turbuhaler® on the aerosolization of API-only powder formulations

Powder dispersion in dry powder inhalers (DPIs) is affected by powder formulations as well as the design of a device. This paper conducted a numerical investigation based on the coupled computational fluid dynamics (CFD) and discrete element method (DEM) to evaluate the changes of the design of a commercial DPI device Turbuhaler® on the aerosolization of an API-only formulation. Six different designs were proposed by modifying the mouthpiece and chamber of the original geometry which was reconstructed from a CT-scan of the Turbuhaler, and their performances in terms of powder deposition in the device and fine powder fraction (FPF) were evaluated. The resistance of the device was observed to vary with different designs. For the change of the mouthpiece, the device with a cylindrical mouthpiece had the least resistance and the lowest FPF emitted among all the devices, confirming the important role of the spiral mouthpiece on powder dispersion. Reducing the mouthpiece size caused more powder deposition in the inhaler due to higher airflow velocity, but FPF emitted increased compared to the original design as more powder dispersion occurred inside the mouthpiece. The half-length mouthpiece design reduced device resistance to increase airflow velocity and average collision energy, resulting in an increase in FPF loaded but a decrease in the number of collisions. For the change of the chamber, the domed chamber design increased the powder dispersion time and thus enhanced the frequency and energy of particle collisions, which eventually led to an increase in FPF loaded. At fixed flow rates, the powder dispersion efficiency was a function of the device resistance with higher device resistance causing an increase in the FPF loaded. However, it is important for the patient's attainable pressure drop to be considered in this context. Correlations between the aerosolization efficiency and the ratio of the average collision energy and cohesion energy were established based on model-predicted quantities.

Can patients achieve sufficient peak inspiratory flow rate (PIFR) with Turbuhaler® during acute exacerbation of asthma?

INTRODUCTION

Anti-inflammatory reliever (AIR) with or without regular maintenance delivered through Turbuhaler® has been widely recommended in the GINA strategy document. These patients are not prescribed with additional reliever inhalers, but dependent on Turbuhaler^® during acute asthma episodes. The peak inspiratory flow rate (PIFR) is crucial in drug delivery from a dry powder inhaler (DPI) such as Turbuhaler^®. Despite its increasing usage, there are some concerns that patients on Turbuhaler^® are not able to achieve adequate PIFR during acute exacerbation of asthma.

OBJECTIVE

This study aimed to assess the PIFR at resistance settings that matched Turbuhaler^® in patients with acute exacerbation of asthma.

METHODOLOGY

A six-month cross-sectional study was conducted at the Emergency Department (ED) of Hospital Sultanah Bahiyah and Hospital Kulim, Kedah, Malaysia. Adult patients diagnosed with mild to moderate acute exacerbations of asthma were recruited. The PIFRs were measured using the In-Check DIAL G16 that was set to simulate the resistance of Turbuhaler^® (R3). The PIFRs were assessed before (pre) and after (post) the initial bronchodilator (BD) treatment at the ED. The minimal required PIFR was defined as flow rates ≥ 30 L/min while a PIFR of 60 L/min was considered as optimal.

RESULTS

A total of 151 patients (81 females and 70 males) were recruited. The mean age was 37.5 years old with a range between 18 and 79 years old. The results showed that 98% (n = 148) of patients managed to achieve the minimal PIFR required for pre-BD. The mean PIFR pre-BD was 60 ± 18.5 L/min and post-BD was 70 ± 18.5 L/min. Furthermore, more than half (54%, n = 82) of the patients recorded PIFR ≥ 60 L/min during pre-BD, and about three-quarters (71%, n = 92) achieved PIFR ≥ 60 L/min post-BD. The PIFR showed a moderate correlation with peak expiratory flow rate (PEFR) (r = 0.55, 95% CI: 0.43-0.65, p < 0.001).

CONCLUSION

The majority of patients with asthma in the present study were able to achieve sufficient PIFR from Turbuhaler^® during mild to moderate acute exacerbations.

Correlation between Hand Grip Strength and Peak Inspiratory Flow Rate in Patients with Stable Chronic Obstructive Pulmonary Disease

Optimal peak inspiratory flow rate (PIFR) is required for effective drug delivery to distal airways when using dry powder inhalers (DPIs). This study aimed to examine the association between PIFR and hand grip strength (HGS) in stable COPD patients. A cross-sectional study was conducted. PIFR was measured using the In-check DIAL to assess for Accuhaler and Turbuhaler DPIs. HGS was measured using a handheld dynamometer. A PIFR of <60 L/min was considered suboptimal PIFR. Demographics, clinical data, and spirometric data were collected and compared. Eighty-one patients (86% men) were included. Mean age was 73.3 ± 8.9 years. FEV1 was 65.3 ± 23.7%. The prevalence of suboptimal PIFR was 38% and 59% for Accuhaler and Turbuhaler, respectively. HGS in the suboptimal PIFR group was lower than in the optimal PIFR group for Accuhaler (22.8 ± 4.7 vs. 33.2 ± 6.9 kg, p < 0.001) and for Turbuhaler (25.3 ± 6.4 vs. 35.1 ± 6.3 kg, p < 0.001). The equation for predicted Accuhaler PIFR (L/min) was −30.340 + (0.274 × hand grip strength) − (0.206 × age) + (0.219 × height) + (1.019 × FVC). The equation for predicted Turbuhaler PIFR (L/min) was 56.196 + (0.321 × hand grip strength) − (0.196 × female) − (0.224 × age) + (0.304 × FVC). The best cutoff values of HGS for predicting optimal PIFR in Accuhaler and Turbuhaler were 26.8 kg (with 82% sensitivity and 84% specificity) and 31.9 kg (with 79% sensitivity and 90% specificity), respectively. In conclusion, HGS correlated with PIFR in patients with clinically stable COPD, especially in the group with pronounced symptoms without frequent exacerbations. HGS threshold values associated with suboptimal PIFR were identified. HGS may be used as an alternative tool to assess an optimal inspiratory force for DPIs.

Comparison of the Efficacy of Budesonide Nebulizer Suspension and Budesonide Inhalation Suspension in the Treatment of Acute Exacerbation of Chronic Obstructive Pulmonary Disease

BACKGROUND

Inhaled corticosteroids have been successfully used to improve lung function. Budesonide nebulizer suspension and Budesonide inhalation suspension are two inhaled corticosteroids used in treating chronic obstructive pulmonary disorder (COPD). We compared the efficacy of Budesonide nebulizer suspension and Budesonide inhalation suspension in the treatment of patients with acute exacerbations of COPD, to prioritize the two treatments.

MATERIALS AND METHODS

In our study, 90 patients were recruited and divided randomly into two groups: Budesonide nebulizer suspension (Pulmicort Nebulizer) and Budesonide inhalation suspension (Pulmicort Turbuhaler) groups. Demographic characteristics, patient clinical information, and paraclinical data including arterial blood gases (ABG) and O₂ Saturation were recorded both at the beginning of hospitalization and on the seventh day of treatment. The collected data were analyzed through independent sample t-test, paired sample t-test, chi-square test, and linear regression using SPSS version 20.

RESULTS

Our findings revealed that there were no significant differences in O₂SAT or ABG between the two groups at baseline or after seven days of treatment (P > 0.05). After seven days of treatment, mean O₂SAT and arterial blood gases had increased significantly in each group (P < 0.001).

CONCLUSION

This study found no significant difference between the two groups with respect to the method of treatment. Therefore, Turbuhaler can be used at home by patients so, it leads to elimination of costs and hospital stays.

Influence of inhaler technique on asthma and COPD control: a multicenter experience

BACKGROUND

The successful management of asthma and chronic obstructive pulmonary disease (COPD) mostly depends on adherence to inhalation drug therapy, the usage of which is commonly associated with many difficulties in real life. Improvement of patients' adherence to inhalation technique could lead to a better outcome in the treatment of asthma and COPD.

OBJECTIVE

The aim of this study was to assess the utility of inhalation technique in clinical and functional control of asthma and COPD during a 3-month follow-up.

METHODS

A total of 312 patients with asthma or COPD who used dry powder Turbuhaler were enrolled in this observational study. During three visits (once a month), training in seven-step inhalation technique was given and it was practically demonstrated. Correctness of patients' usage of inhaler was assessed in three visits by scoring each of the seven steps during administration of inhaler dose. Assessment of disease control was done at each visit and evaluated as: fully controlled, partially controlled, or uncontrolled. Patients' subjective perception of the simplicity of inhalation technique, disease control, and quality of life were assessed by using specially designed questionnaires.

RESULTS

Significant improvement in inhalation technique was achieved after the third visit compared to the first one, as measured by the seven-step inhaler usage score (5.94 and 6.82, respectively; P<0.001). Improvement of disease control significantly increased from visit 1 to visit 2 (53.9% and 74.5%, respectively; P<0.001) and from visit 2 to visit 3 (74.5% and 77%, respectively; P<0.001). Patients' subjective assessment of symptoms and quality of life significantly improved from visit 1 to visit 3 (P<0.001).

CONCLUSION

Adherence to inhalation therapy is one of the key factors of successful respiratory disease treatment. Therefore, health care professionals should insist on educational programs aimed at improving patients' inhalation technique with different devices, resulting in better long-term disease control and improved quality of life.

Onset of action of budesonide/formoterol Spiromax(®) compared with budesonide/formoterol Turbuhaler(®) in patients with COPD

Budesonide/formoterol (BF) is available in two delivery systems, the dry powder inhaler (DPI) Turbuhaler and a pressurized metered dose inhaler (pMDI) for use in patients with asthma or chronic obstructive pulmonary disease (COPD). Spiromax DPI was recently developed as an alternative to Turbuhaler DPI. In the present study, we examined whether there is a difference in the onset of bronchodilatation between BF 320/9 μg delivered by Spiromax and BF 320/9 μg delivered by Turbuhaler in 16 outpatients with stable moderate-to-severe COPD. Our results confirm the rapid onset of action of formoterol when combined with budesonide in patients with COPD and indicate that the onset of bronchodilation induced by BF Spiromax is faster than that elicited by BF Turbuhaler. Furthermore, they show that BF fixed-dose combination does not induce a decrease in SpO2 or an increase in heart rate in patients with COPD, irrespective of the DPI used to deliver this combination. Given the evidence that both inhalers have an equal safety profile, BF Spiromax offers to prescribers and COPD patients an effective alternative to BF Turbuhaler depending also on their preference, availability and cost.

A randomized, double-blinded, double-dummy efficacy and safety study of budesonide-formoterol Spiromax® compared to budesonide-formoterol Turbuhaler® in adults and adolescents with persistent asthma

Background

Budesonide and formoterol (BF) Spiromax® is a dry powder inhaler designed to deliver BF with maximum ease of use for patients with asthma or chronic obstructive pulmonary disease.

Methods

A phase 3b, 12-week, multicenter, double-blind, double-dummy, randomized, controlled trial in patients (≥12 years) with persistent asthma. Primary objective: to demonstrate non-inferiority of twice-daily BF Spiromax 160/4.5 mcg to BF Turbuhaler® 200/6 mcg in change from baseline in weekly average of daily trough morning peak expiratory flow (PEF). Secondary endpoints included: Patient Satisfaction and Preference Questionnaire scores, change from baseline in evening PEF, trough forced expiratory volume in one second, percentage of symptom-free and rescue-free 24-hour periods, and safety.

Results

The analysis was based on the per-protocol population (BF Spiromax, n = 290; BF Turbuhaler, n = 284). The least squares mean change from baseline to week 12 in morning PEF was: BF Spiromax, 18.8 L/min and BF Turbuhaler, 21.8 L/min. Non-inferiority of BF Spiromax vs BF Turbuhaler was demonstrated (the lower limit of the 95 % two-sided confidence interval was −9.02 L/min, which is greater than −15 L/min [the criteria specified for non-inferiority]). The mean difference in the total performance domains scores for BF Spiromax vs BF Turbuhaler were 0.248 at baseline and 0.353 at week 12 (both, p <0.001), indicating statistical superiority for BF Spiromax. No statistical or numerical differences were recorded in the total convenience domain score between the two devices. Scores for ‘device preference’ and ‘willingness to continue’ supported BF Spiromax at baseline and at week 12 (p = 0.0005 vs BF Turbuhaler). No significant between-group differences were observed in the other secondary efficacy endpoints. Both treatments were well tolerated, with no significant differences in adverse events or asthma exacerbations.

Conclusions

This study demonstrates the non-inferiority of BF Spiromax vs BF Turbuhaler in patients (≥12 years) with asthma. More patients preferred the Spiromax device over Turbuhaler for its performance, and were willing to continue therapy with BF Spiromax beyond the 12-week study period.

Trial registration

NCT01803555; February 28, 2013.

Electronic supplementary material

The online version of this article (doi:10.1186/s12890-016-0200-x) contains supplementary material, which is available to authorized users.

Monitoring Inhaler Inhalations Using an Acoustic Sensor Proximal to Inhaler Devices

BACKGROUND

The efficacy of drug delivery from inhalers is very much dependent on the user's peak inspiratory flow rate (PIFR). Current methods to measure PIFR in inhalers are based on subjective checklists. There is a lack of methods currently available to objectively remotely monitor PIFR in pressurized metered dose inhalers (pMDIs) and dry powder inhalers (DPIs). In this study, for the first time, non-contact acoustic methods were employed to estimate PIFR through three commonly used inhalers (Diskus™ DPI, Turbuhaler™ DPI, and Evohaler™ pMDI) with the aim of applying these methods to remotely monitor inhaler inhalation technique in future clinical applications.

METHODS

Each inhaler was placed inside an airtight container connected to a spirometer to measure PIFR. A high quality microphone was placed 5 cm from the mouthpiece of the inhalers to record inhalation sounds. Over 2000 inhaler inhalation sounds were recorded from 11 healthy participants. A range of temporal and spectral acoustic features from the inhalation sounds were correlated with PIFR. The variation of acoustic features and the repeatability of the inhalation acoustic spectral profile were investigated to further characterize inhaler inhalation sounds and to determine the reliability of acoustics to estimate PIFR.

RESULTS

All acoustic features were significantly correlated with PIFR (p < 0.001). The mean power of the inhalation sound generated the most consistent correlation across all inhalers [R² = 0.77 (Diskus™), R² = 0.7 (Turbuhaler™), R² = 0.75 (Evohaler™)]. Acoustic features generated low variation and the spectral profile of inhalation sounds was repeatable regardless of flow rate, suggesting that acoustic methods are a reliable method of estimating PIFR.

CONCLUSIONS

The methods presented in this study may be employed in a wearable monitoring device in future applications to measure inhaler PIFR. Objective monitoring of PIFR in inhalers may help patients improve their inhaler inhalation technique and therefore may be of significant clinical benefit to both patients and clinicians.

Equivalent Lung Dose and Systemic Exposure of Budesonide/Formoterol Combination via Easyhaler and Turbuhaler

BACKGROUND

Easyhaler(®) device-metered dry powder inhaler containing budesonide and formoterol fumarate dihydrate (hereafter formoterol) for the treatment of asthma and chronic obstructive pulmonary disease has been developed. The current approvals of the product in Europe were based on several pharmacokinetic (PK) bioequivalence (BE) studies, and in vitro-in vivo correlation (IVIVC) modeling.

METHODS

Four PK studies were performed to compare the lung deposition and total systemic exposure of budesonide and formoterol after administration of budesonide/formoterol Easyhaler and the reference product, Symbicort Turbuhaler. The products were administered concomitantly with oral charcoal (lung deposition) and in two of the studies also without charcoal (total systemic exposure). Demonstration of BE for lung deposition (surrogate marker for efficacy) and non-inferiority for systemic exposure (surrogate marker for safety) were considered a proof of therapeutic equivalence. In addition, IVIVC models were constructed to predict study outcomes with different reference product fine particle doses (FPDs).

RESULTS

In the first pivotal study, the exposure and lung dose via Easyhaler were higher compared to the reference product (mean comparison estimates between 1.07 and 1.28) as the FPDs of the reference product batch were low. In the following studies, reference product batches with higher FPDs were utilized. In the second pivotal study, non-inferiority of Easyhaler compared to Turbuhaler was shown in safety and BE in efficacy for all other parameters except the formoterol AUCt. In the fourth study where two reference batches were compared to each other and Easyhaler, budesonide/formoterol Easyhaler was bioequivalent with one reference batch but not with the other having the highest FPDs amongst the 28 reference batches studied. In the IVIVC based study outcome predictions, the test product was bioequivalent with great proportion of the reference batches. For the test product and the median FPD reference product BE was predicted.

CONCLUSIONS

Equivalence regarding both safety and efficacy between budesonide/formoterol Easyhaler and Symbicort Turbuhaler was shown based on totality of evidence from the PK studies and IVIVC analyses, and therefore, therapeutic equivalence between the products can be concluded. The results of the PK studies are likely dependent on the variability of FPDs of the reference product batches.

Deposition and fine particle production during dynamic flow in a dry powder inhaler: a CFD approach

In this work the dynamic flow as well as the particle motion and deposition in a commercial dry powder inhaler, DPI (i.e., Turbuhaler) is described using computational fluid dynamics, CFD. The dynamic flow model presented here is an extension of a steady flow model previously described in Milenkovic et al. (2013). The model integrates CFD simulations for dynamic flow, an Eulerian-fluid/Lagrangian-particle description of particle motion as well as a particle/wall interaction model providing the sticking efficiency of particles colliding with the DPI walls. The dynamic flow is imposed by a time varying outlet pressure and the particle injections into the DPI are assumed to occur instantaneously and follow a prescribed particle size distribution, PSD. The total particle deposition and the production of fine particles in the DPI are determined for different peak inspiratory flow rates, PIFR, flow increase rates, FIR, and particle injection times. The simulation results for particle deposition are found to agree well with available experimental data for different values of PIFR and FIR. The predicted values of fine particle fraction are in agreement with available experimental results when the mean size of the injected PSD is taken to depend on the PIFR.

Skills in handling turbuhaler, diskus, and pressurized metered-dose inhaler in korean asthmatic patients

Purpose

The objective of this study was to evaluate skills in handling inhalers and factors associated with these skills among patients with asthma who had undergone treatment at special asthma and allergy clinics in Korea.

Methods

We enrolled 78 subjects who used Turbuhaler and 145 who used Diskus for asthma control at special clinics in 10 university hospitals and visually assessed their skills in handling these inhalers. We also evaluated skills in 137 subjects who had used pressurized metered-dose inhalers (pMDIs) for symptom relief. Age, sex, duration of asthma and inhaler use, smoking status, monthly income, highest grade completed in school and previous instruction for handling inhalers were also measured to evaluate their association with overall inhaler skills.

Results

Performance grade was inadequate for 12.8% of participants using Turbuhaler, 6.2% for Diskus, and 23.4% for pMDIs. The success rates for each step in handling the inhalers were relatively high except for the "exhale slowly to residual volume" step, in which success rates ranged from 24.2% to 28.5%. Older age, male sex, lower educational grade, and absence of previous instruction for handling inhalers were associated with inadequate inhaler technique in univariate analysis; however, only older age and absence of previous instruction remained significant independent risk factors in multivariate analysis.

Conclusions

Among Korean asthmatic patients in special asthma and allergy clinics, skills in handling their inhalers were mostly excellent; meanwhile, older age and absence of previous instruction for handling inhalers were associated with inadequate techniques.

Comparison of small-group training with self-directed internet-based training in inhaler techniques

OBJECTIVES

To compare the effectiveness of small-group training in correct inhaler technique with self-directed Internet-based training.

DESIGN

Pharmacy students were randomly allocated to 1 of 2 groups: small-group training (n = 123) or self-directed Internet-based training (n = 113). Prior to intervention delivery, all participants were given a placebo Turbuhaler and product information leaflet and received inhaler technique training based on their group. Technique was assessed following training and predictors of correct inhaler technique were examined.

ASSESSMENT

There was a significant improvement in the number of participants demonstrating correct technique in both groups (small group training, 12% to 63%; p < 0.05; and Internet-based training, 9% to 59%; p < 0.05) post intervention, with no significant difference between the groups in the percent change (n = 234, p > 0.05). Increased student confidence following the intervention was a predictor for correct inhaler technique.

CONCLUSIONS

Self-directed Internet-based training is as effective as small-group training in improving students' inhaler technique.