In-vitro intra- and inter-inhaler flow rate-dependent dosage emission from a combination of budesonide and eformoterol in a dry powder inhaler

The effect of exhalation before the inhalation of dry powder aerosol drugs on the breathing parameters, emitted doses and aerosol size distributions

Airway deposition of aerosol drugs is highly dependent on the breathing manoeuvre of the patients. Though incorrect exhalation before the inhalation of the drug is one of the most common mistakes, its effect on the rest of the manoeuvre and on the airway deposition distribution of aerosol drugs is not explored in the open literature. The aim of the present work was to conduct inhalation experiments using six dry powder inhalers in order to quantify the effect of the degree of lung emptying on the inhalation time, inhaled volume and peak inhalation flow. Another goal of the research was to determine the effect of the exhalation on the aerodynamic properties of the drugs emitted by the same inhalers. According to the measurements, deep exhalation before drug inhalation increased the volume of the inhaled air and the average and maximum values of the inhalation flow rate, but the extent of the increase was patient and inhaler specific. For different inhalers, the mean value of the relative increase in peak inhalation flow due to forceful exhalation was between 15.3 and 38.4% (min: Easyhaler®, max: Breezhaler®), compared to the case of normal (tidal) exhalation before the drug inhalation. The relative increase in the inhaled volume was between 36.4 and 57.1% (min: NEXThaler®, max: Turbuhaler®). By the same token, forceful exhalation resulted in higher emitted doses and smaller emitted particles, depending on the individual breathing ability of the patient, the inhalation device and the drug metered in it. The relative increase in the emitted dose varied between 0.2 and 8.0% (min: Foster® NEXThaler®, max: Bufomix® Easyhaler®), while the relative enhancement of fine particle dose ranged between 1.9 and 30.8% (min: Foster® NEXThaler®, max: Symbicort® Turbuhaler®), depending on the inhaler. All these effects and parameter values point toward higher airway doses due to forceful exhalation before the inhalation of the drug. At the same time, the present findings highlight the necessity of proper patient education on the importance of lung emptying, but also the importance of patient-specific inhaler-drug pair choice in the future.

Optimal Inhalation Flow Pattern from Turbuhaler Predicted by Laser Photometry

Background: The emitted dose (ED) from most dry powder inhalers (DPIs) is almost independent of peak inspiratory flow (PIF) above a certain value, which is specific to the individual DPI. However, the ED of the Turbuhaler^® (TBH) increases linearly with PIF increments. This study investigated the powder clearance and clinical utility of TBH performance features by using the photo-reflection method (PRM), a type of laser photometry. Methods: Pulmicort^® (PLM) (containing budesonide only) and Symbicort^® (SMB) (drugs with lactose particles) were inspired with a ramp-up pattern of several PIF intensities using a vacuum pump. Time trajectories of particle release and PIF were then compared. Results: The particle-release trajectories from both types of DPIs were similar, consisting of a sharp increment phase (∼0.15 seconds) followed by exponential decay. Both onset to the peak of particle-release time and particle-release times were not affected by PIF changes when the PIF was >40 L/min. EDs from both TBHs were linearly related to PIFs, and the slope of the regression equation for SMB was 2.4-fold larger than that of PLM. The peak of the released particles (PK_IED) was also linearly related to PIF. A linear relationship was also observed between ED and PK_IED in both TBHs, and these regression lines overlapped. Conclusion: EDs from the TBH were dependent on PK_IED. Therefore, rapid, initially strong, and deep inhalation should be advised while using the TBH. PRM could measure the fine and small amount of particles released from the TBH.

Performance Characteristics of Breezhaler® and Aerolizer® 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.

In vitro and in vivo performance modelling and optimisation of different dry powder inhalers: A complementary study of neural networks, genetic algorithms and decision trees

INTRODUCTION

Aerosol delivery from DPIs could be affected by different factors. This study aimed to evaluate and predict the effects of different factors on drug delivery from DPIs.

METHODS

Modelling and optimisation for both in vitro and in vivo data of different DPIs (Diskus, Turbohaler and Aerolizer) were carried out using neural networks associated with genetic algorithms and the results are confirmed using a decision tree (DT) and random forest regressor (RFR). All variables (the type of DPI, inhalation flow, inhalation volume, number of inhalations and type of subject) were coded as numbers before using them in the modelling study.

RESULTS

The analysis of the in vitro model showed that Turbohaler had the highest emitted dose compared with the Diskus and the Aerolizer. Increasing flow resulted in a gradual increase in the emitted dose. Little differences between the inhalation volumes 2 and 4 litres were shown at fast inhalation flow, and interestingly two inhalations showed somewhat higher emitted doses than one-inhalation mode with Turbohaler and Diskus at slow inhalation flow. Regarding the in vivo model, the percent of drug delivered to the lung was highly increased with Turbohaler and Diskus in healthy subjects where continuous contour lines were observed. The Turbohaler showed increased lung bioavailability with the two-inhalation modes, the Diskus showed a nearly constant level at both one and two inhalations at slow inhalation. The Turbohaler and Aerolizer showed little increasing effect moving from one to two inhalations at slow inhalation.

CONCLUSIONS

Modelling of the input data showed a good differentiating and prediction power for both in vitro and in vivo models. The results of the modelling refer to the high efficacy of Diskus followed by Turbohaler for delivering aerosol. With two inhalations, the three DPIs showed an increase in the percent of drug excreted at slow inhalations.

The role of inspiratory flow in selection and use of inhaled therapy for patients with chronic obstructive pulmonary disease

Inhalation therapy is the mainstay of chronic obstructive pulmonary disease management, and inhaler selection can have a profound impact on drug delivery and medication adherence, as well as on treatment outcomes. Although multiple delivery systems, such as pressurized metered-dose inhalers, dry powder inhalers, slow-mist inhalers, and nebulizers, are available, clinical benefits achieved by patients rely on effective delivery of the inhaled medication to the airways. Among several factors influencing drug deposition, inspiratory flow is one of the most important. Inspiratory flow impacts drug delivery and subsequent clinical efficacy, making it necessary to adequately train patients to ensure correct inhaler use. Peak inspiratory flow is the maximal airflow generated during a forced inspiratory maneuver. Health care professionals need to select the appropriate delivery system after carefully considering patient characteristics, including lung function, optimal inspiratory flow, manual dexterity, and cognitive function. Herein, the role of inspiratory flow in the selection and use of inhaled therapy in patients with COPD is reviewed.

Real-life budesonide and formoterol dose emission from the medium and high strength fixed dosed combinations in a Spiromax® dry powder inhaler using inhalation profiles from patients with chronic obstructive pulmonary disease

Dry powder inhalers (DPIs) are passive devices used to administer inhaled medication for the management of asthma and chronic obstructive pulmonary disease (COPD). DPIs require patients to generate a sufficient internal turbulent airflow force during each inhalation to deaggregate the powdered drug formulation into an emitted dose containing particles with the greatest likelihood of lung deposition. This internal force is generated by the interaction between the user's inhalation flow and the resistance of the DPI. Traditional compendial in vitro methods of measuring dose emission use a vacuum pump to simulate inhalation. We have adapted this in vitro method by replacing the square wave inhalation profile generated by a vacuum pump with the inhalation profiles of patients using an empty DPI. This method enables accurate assessment of the actual dose they would have inhaled. In the present study, real-life inhalation profiles were selected from 15 patients with COPD who inhaled through an empty placebo Spiromax® DPI. Ex vivo dose emissions were measured for the medium (emitted dose of 160 μg/4.5 μg) and high-strength (320 μg/9 μg) budesonide/formoterol formulations from the Spiromax DPI. These profiles were used to investigate the effect of the primary inhalation parameter-peak inhalation flow (PIF). Some profiles were modified to isolate other inhalation parameters (namely, inhaled volume [V_in] and acceleration rate of the inhalation maneuver [ACIM]). Both the medium-strength and high-strength DuoResp Spiromax displayed flow-dependent dose emission. When the PIF of a patient's inhalation maneuver increased from 26.8 L/min to 69.7 L/min, there was a significant (p < 0.05) effect on the dose-emission characteristics of the medium-strength and high-strength DuoResp Spiromax. At each PIF, an increase in V_in from approximately 500 mL to 2000 mL had no effect on the dose-emission characteristics of either strength. However, at each V_in there was a significant (p < 0.05) effect on the dose-emission characteristics as PIF increased. The effect of ACIM on the dose-emission characteristics was small. The ex vivo methodology used in this study provides a practical approach to identify the actual dose a patient might inhale during routine real-life use of the DuoResp Spiromax.

Easyhaler®: an overview of an inhaler device for day-to-day use in patients with asthma and chronic obstructive pulmonary disease

Inhalation therapy is likely to continue to dominate asthma and chronic obstructive pulmonary disease (COPD) treatment. The pressurised metered-dose inhaler (pMDI) accounts for most of the global inhaler market, but this kind of device is difficult to use properly. Dry powder inhalers (DPIs) have several advantages over pMDIs: they are breath-activated, easy and convenient to use, and environmentally friendly. The Easyhaler^® (Orion; Finland) is a multidose reservoir-type DPI developed to efficiently deliver a wide range of medications, including fixed-dose combinations of bronchodilators and corticosteroids. Easyhaler shares a similar shape with the pMDI, and its performance is unaffected by moisture, dropping, vibration, and freezing/thawing. For these reasons, Easyhaler may be considered one of the most convenient inhalers for daily use in patients with asthma or COPD.

Simulation of Airway Deposition of an Aerosol Drug in COPD Patients

Medical aerosols are key elements of current chronic obstructive pulmonary disease (COPD) therapy. Therapeutic effects are conditioned by the delivery of the right amount of medication to the right place within the airways, that is, to the drug receptors. Deposition of the inhaled drugs is sensitive to the breathing pattern of the patients which is also connected with the patient's disease severity. The objective of this work was to measure the realistic inhalation profiles of mild, moderate, and severe COPD patients, simulate the deposition patterns of Symbicort^® Turbuhaler^® dry powder drug and compare them to similar patterns of healthy control subjects. For this purpose, a stochastic airway deposition model has been applied. Our results revealed that the amount of drug depositing within the lungs correlated with the degree of disease severity. While drug deposition fraction in the lungs of mild COPD patients compared with that of healthy subjects (28% versus 31%), lung deposition fraction characteristic of severe COPD patients was lower by a factor of almost two (about 17%). Deposition fraction of moderate COPD patients was in-between (23%). This implies that for the same inhaler dosage severe COPD patients receive a significantly lower lung dose, although, they would need more.

Real life dose emission characterization using COPD patient inhalation profiles when they inhaled using a fixed dose combination (FDC) of the medium strength Symbicort® Turbuhaler®

The dose emitted from dry powder inhalers (DPI) is inhalation flow dependent and so varies with the peak inhalation flow (PIF) of a patient's inhalation maneuver (IM). Dose emission could also be affected by other IM parameters-the inhaled volume (V_in) and the initial acceleration rate of the IM (ACIM). We have adapted the compendial method for in-vitro DPI determinations so that inhalation profiles replace the inhalation square profile generated by a vacuum pump. These real-life patient inhalation profiles were measured when 18 COPD patients inhaled through an empty placebo Symbicort^® Turbuhaler^®. They have been used to identify the dose emission characteristics from a fixed dosed combination of 200μg budesonide plus 6μg formoterol Turbuhaler^®. To isolate each inhalation parameter some profiles were modified to provide a further 9 profiles to study the influence of V_in and 27 to identify the effect of ACIM. The fine particle dose, total emitted dose and mass median aerodynamic diameter were significantly (p<0.05) influenced by PIF (p<0.05) whereas ACIM and V_in had only a small effect. The results show the value of this ex-vivo methodology to provide an insight into the dose that each patient would have inhaled during real-life use.

Numerical simulation of emitted particle characteristics and airway deposition distribution of Symbicort(®) Turbuhaler(®) dry powder fixed combination aerosol drug

One of the most widespread dry powder fixed combinations used in asthma and chronic obstructive pulmonary disease (COPD) management is Symbicort(®) Turbuhaler(®). The aim of this study was to simulate the deposition distribution of both components of this drug within the airways based on realistic airflow measurements. Breathing parameters of 25 healthy adults (11 females and 14 males) were acquired while inhaling through Turbuhaler(®). Individual specific emitted doses and particle size distributions of Symbicort(®) Turbuhaler(®) were determined. A self-developed particle deposition model was adapted and validated to simulate the deposition of budesonide (inhaled corticosteroid; ICS) and formoterol (long acting β2 agonist; LABA) in the upper airways and lungs of the healthy volunteers. Based on current simulations the emitted doses varied between 50.4% and 92.5% of the metered dose for the ICS, and between 38% and 96.1% in case of LABA component depending on the individual inhalation flow rate. This variability induced a notable inter-individual spread of the deposited lung doses (mean: 33.6%, range: 20.4%-48.8% for budesonide and mean: 29.8%, range: 16.4%-42.9% for formoterol). Significant inter-gender differences were also observed. Average lung dose of budesonide was 29.2% of the metered dose for females and 37% for males, while formoterol deposited with 26.4% efficiency for females and 32.5% for males. Present results also highlighted the importance of breath-holding after inhalation of the drug. About a half of the total lung deposition occurred during breath-hold at 9.6s average breath-hold time. Calculated depositions confirmed appropriate lung deposition of Symbicort(®) Turbuhaler(®) for both genders, however more effort for optimal inhalation technique is advised for persons with low vital capacity. This study demonstrated the possibility of personalized prediction of airway deposition of aerosol drugs by numerical simulations. The methodology developed in this study will be applicable also to other marketed drugs in the future.

Inhalation device requirements for patients' inhalation maneuvers

BACKGROUND

Inhaled drugs are the mainstay of treatment for lung diseases such as asthma and chronic obstructive pulmonary disease. However, failure to use inhalation devices correctly can lead to a poorly controlled status. A vast number of inhalation devices exist and each device has specific requirements to achieve optimum inhalation of the drug. Currently, there is no overview of inhalation requirements considering all devices. This article presents a review of the literature on different inhalation device requirements and incorporates the data into a new inhalation flow algorithm.

METHODS

Data from literature on commercially available inhalation devices were evaluated and parameters, such as inhalation flow rate, flow acceleration, inhalation volume, and inspiration time assessed for the required inhalation maneuver specific to the device. All agreed upon data points were used to develop an inhalation flow algorithm.

RESULTS

The literature analysis revealed availability of robust data for the required inhalation flow characteristics for most devices and thus for the development of an algorithm. For those devices for which these parameters are not published, the minimum required flow criteria were defined based on published data regarding individual aspects of aerosol quality.

CONCLUSIONS

This review provides an overview of inhalation devices available on the market regarding requirements for an acceptable inhalation maneuver and shows which goals should be achieved in terms of inhalation flows. The presented algorithm can be used to develop a new computer based measurement system which could help to test and train patients' individual inhalation maneuvers with their inhalation devices.

Revising old principles of inhaled treatment in new fixed combinations for asthma

The major influencing factors on persistent asthma control are the selected treatment(s), the drug delivery route and patient's adherence to therapy, together with the influence of lifestyle (i.e. sedentary habit), comorbid conditions and specific asthma phenotypes. Inhaled corticosteroids (ICS) in combination with a long-acting β2-agonist (LABA) are the gold standard for management of persistent asthma, with maximal local targeting and minimal systemic side effects. Several innovative inhaler devices have been developed for effective local drug administration and good patient compliance to therapy. Recently, a new ICS/LABA fixed combination, formulated with fluticasone propionate (FP) and formoterol fumarate (FF), has been proposed for maintenance treatment of asthma in adults and adolescent patients. FP/FF combines the anti-inflammatory and bronchodilating properties of powerful compounds in a single inhaler. Its pharmacological characteristics allow rapid speed of onset and dosage flexibility required for step-up and step-down strategies, improving adherence to treatment of asthmatic patients. The efficacy of the FP/FF fixed combination at all dosages in controlling asthma symptoms and the reduced rate of discontinuation have been demonstrated by all randomized trials conducted so far.

Turning a molecule into a medicine: the development of indacaterol as a novel once-daily bronchodilator treatment for patients with COPD

Indacaterol is the first once-daily, long-acting β2-adrenergic agonist (LABA) approved for the treatment of chronic obstructive pulmonary disease (COPD). Indacaterol was developed using a combination of informed drug design and molecular chemistry to generate a β2-adrenergic agonist with a fast onset and long duration of action, enabling once-daily dosing with an acceptable safety profile. Early preclinical studies with indacaterol demonstrated these characteristics, and this promising molecule was taken into clinical development, originally for asthma treatment. Subsequent safety concerns over LABA monotherapy in patients with asthma redirected indacaterol's development to centre on COPD, where a good evidence base and guideline recommendations for bronchodilator monotherapy existed. Clinical development was initially complicated by different inhaler devices and differing doses of indacaterol. Using a phase III innovative adaptive-design clinical trial (INHANCE), indacaterol 150 and 300 μg once-daily doses were selected to be taken forward into the phase III INERGIZE programme. This programme delivered placebo-controlled and active-comparator data, including comparisons with formoterol, tiotropium and salmeterol/fluticasone, as well as the use of indacaterol in combination with tiotropium. Together, these studies provided a comprehensive assessment of the benefit-risk profile of indacaterol, allowing for regulatory submission. Indacaterol was first approved at once-daily doses of 150 and 300 μg in the European Union in 2009, followed by 150 µg in Japan (2011) and China (2012), and 75 μg in the United States (2011). To date, indacaterol is approved and marketed in more than 100 countries worldwide for once-daily maintenance treatment of COPD.

Real-world effects of two inhaled corticosteroid/long-acting β₂-agonist combinations in the treatment of asthma

OBJECTIVE

There are several inhaled corticosteroid/long-acting β2-agonist (ICS/LABA) combinations currently used to treat asthmatic patients, but the differences in the clinical effects of these ICS/LABAs are currently unknown. We herein evaluated the effects of two currently available ICS/LABA combinations in a real-world setting.

METHODS

A fluticasone propionate/salmeterol combined Discus inhaler (FP/SM; 250/50 μg bid) was switched to a budesonide/formoterol Turbuhaler inhaler (BUD/FM; 160/4.5 μg two inhalations bid) and FP/SM (500/50 μg bid) was also switched to BUD/FM (160/4.5 μg four inhalations bid) in symptomatic asthmatic patients treated with FP/SM over 20 years of age.

RESULTS

Sixty patients were enrolled in this study, and the scores of the asthma control test (ACT) and asthma control questionnaire-5 item version (ACQ5) were significantly improved 4 and 8 weeks after the switch to ICS/LABA treatments, and well-controlled asthma (ACQ5 score <0.75) and good control (ACT score >20) was achieved in 54 (90%) and 40 (66.7%) patients, respectively, at 8 weeks. The spirometric analysis revealed significant improvements of the values of the peak expiratory flow (PEF) and forced expiratory volume in one second (FEV1) after switching from FP/SM to BUD/FM, and significantly improved small airway impairments ([Formula: see text]50 and [Formula: see text]25) were observed in patients treated with high-dose ICS/LABA. These subjective and objective improvements were also seen in patients aged over 65 years old.

CONCLUSION

These data demonstrated that changing the combined ICS/LABA inhaler from FP/SM to BUD/FM can lead to more effective management of symptomatic patients with asthma, especially in patients treated with high-dose ICS/LABA.

A comparison of long-term anti-inflammatory effect of two ICS/LABA combination inhalers; fix-dosed maintenance therapy with budesonide/formoterol and salmeterol/fluticasone

BACKGROUND

The clinical usefulness of fixed-dose maintenance therapy with salmeterol/fluticasone (SFC) and budesonide/formoterol combination inhaler (BUD/FM) has been established, though evidence of the long-term anti-inflammatory effects of these 2 inhalers are limited.

METHODS

Patients with moderate persistent adult asthma who had received SFC 50/250μg bid with well-control status were recruited. After switching to 8-week therapy with fixed-dose BUD/FM 4 puffs (640/18μg) (phase-1), patients chose either SFC or BUD/FM. FeNO and ACT score were evaluated every 8 weeks until the end of the 52-week treatment period for both treatment groups (phase-2).

RESULTS

In total, 103 patients were examined: BUD/FM was chosen by 34 patients (BUD/FM group), while SFC was chosen by 23 (SFC group). Thirty-six received SFC consistently from the beginning of the study (control). Patients in the BUD/FM and SFC groups showed significant improvements in ACT scores and FeNO levels in phase-1; these beneficial effects persisted for 52 weeks in the BUD/FM group. On the other hand, in the SFC group, although the FeNO level decreased from 54.3 ± 26.4 ppb to 41.9 ± 18.3 ppb in phase-1, it increased to 54.5 ± 26.2 ppb, a level similar to the baseline prior to the beginning of BUD/FM therapy, at 8 weeks in phase-2, and remained at 50-odd ppb thereafter.

CONCLUSIONS

These results suggest that maintenance therapy with fixed-dose BUD/FM is a useful treatment option exerting an airway anti-inflammatory effect for a period as long as 1 year, even for asthmatics who could not accomplish total control with SFC.

Pharmaceutical equivalence of the combination formulation of budesonide and formoterol in a single capsule with a dry powder inhaler

OBJECTIVE

To evaluate the pharmaceutical equivalence of a test formulation (fixed-dose combination of budesonide and formoterol fumarate in a single capsule dispensed in an Aerocaps® inhaler) in relation to a reference formulation (budesonide and formoterol fumarate in two separate capsules dispensed in an Aerolizer® inhaler).

METHODS

This was an in vitro study in which we performed the identification/quantification of the active ingredients by HPLC and determined dose uniformity and aerodynamic particle size distribution in the test and reference formulations.

RESULTS

In the test formulation, the content of budesonide and formoterol was 111.0% and 103.8%, respectively, compared with 110.5% and 104.5%, respectively, in the reference formulation. In the test formulation, dose uniformity regarding budesonide and formoterol was 293.2 µg and 10.2 µg, respectively, whereas it was 353.0 µg and 11.1 µg in the reference formulation. These values are within the recommended range for this type of formulation (75-125% of the labeled dose). The fine particle fraction (< 5 µm) for budesonide and formoterol was 45% and 56%, respectively, in the test formulation and 54% and 52%, respectively, in the reference formulation.

CONCLUSIONS

For both of the formulations tested, the levels of active ingredients, dose uniformity, and aerodynamic diameters were suitable for use with the respective dry powder inhalers.

Aerodynamic dose emission characteristics of dry powder inhalers using an Andersen Cascade Impactor with a mixing inlet: the influence of flow and volume

An interaction between device resistance and inhalation flow provides the 'energy' to de-aggregate the metered dose of dry powder inhalers (DPIs). Hence all dry powder inhalers demonstrate flow dependent dose emission but information on this at low flows is not available. We have adapted the compendial method for the Andersen Cascade Impactor (ACI) to include a mixing inlet to determine the aerodynamic dose emission characteristics of a salbutamol Diskus(®) [DSK], Easyhaler(®) [EASY] and Clickhaler(®) [CLICK] and the terbutaline Turbuhaler(®) [TBH] using flows of 10-60 L/min and inhalation volumes of 2 and 4 L. All DPIs demonstrated flow dependent dose emission (p<0.001) but there was no difference in the measurements between 2 and 4 L. The flow dependent dose emission properties of each DPI started to plateau when the pressure change inside each device, during an inhalation, was between 1 and 1.5 kPa. This corresponds to inhalation flows of 40.1-49.1, 25.4-28.9, 23.6-28.9 and 29.7-36.3 L/min through DSK, CLICK, EASY and TBH. The adapted methodology allows measurements at low flows. The results highlight that the compendial methodology to use an inhaled volume of 4 L with the ACI could be replaced by 2 L and that the recommendation to make measurements using a pressure drop of 4kPa should be revised.

Switching from salmeterol/fluticasone to formoterol/budesonide combinations improves peripheral airway/alveolar inflammation in asthma

BACKGROUND

Combination therapy with an inhaled corticosteroid (ICS) and a long-acting β2-agonist (LABA) in a single inhaler is the mainstay of asthma management. We previously showed that switching from salmeterol/fluticasone combination (SFC) 50/250 μg bid to a fixed-dose formoterol/budesonide combination (FBC) 9/320 μg bid improved asthma control and pulmonary functions, but not fractional exhaled nitric oxide (FeNO), in patients with asthma not adequately controlled under the former treatment regimen.

OBJECTIVE

To assess whether switching from SFC to FBC improves peripheral airway/alveolar inflammation in asthma (UMIN000009619).

METHODS

Subjects included 66 patients with mild to moderate asthma receiving SFC 50/250 μg bid for more than 8 weeks. Patients were randomized into FBC 9/320 μg bid or continued the same dose of SFC for 12 weeks. Asthma Control Questionnaire, 5-item version (ACQ5) score, peak expiratory flow, spirometry, FeNO, alveolar NO concentration (CANO), and maximal NO flux in the conductive airways (J'awNO) were measured.

RESULTS

Sixty-one patients completed the study. The proportion of patients with an improvement in ACQ5 was significantly higher in the FBC group than in the SFC group (51.6% vs 16.7%, respectively, p = 0.003). A significant decrease in CANO was observed in the FBC group (from 8.8 ± 9.2 ppb to 4.0 ± 2.6 ppb; p = 0.007) compared to the SFC group (from 7.4 ± 7.8 ppb to 6.4 ± 5.0 ppb; p = 0.266) although there was no significant difference in the changes in pulmonary functions between the 2 groups. Similar significant differences were found in the CANO corrected for the axial back diffusion of NO (FBC, from 6.5 ± 8.2 ppb to 2.3 ± 2.5 ppb; and SFC, from 4.3 ± 5.3 ppb to 3.9 ± 4.3 ppb). There was no difference in the changes in FeNO or J'awNO between the 2 groups.

CONCLUSIONS

Switching therapy from SFC to FBC improves asthma control and peripheral airway/alveolar inflammation even though there is no improvement in pulmonary functions, and FeNO in asthmatic patients.

Effect of switching from salmeterol/fluticasone to formoterol/ budesonide combinations in patients with uncontrolled asthma

BACKGROUND

Combination therapy with an inhaled corticosteroid (ICS) and a long-acting β(2)-agonist (LABA) in a single inhaler is the mainstay of asthma management and salmeterol/fluticasone combination (SFC) and fixed-dose formoterol/budesonide combination (FBC) are currently available in Japan; however, there is nothing to choose between the two. The purpose of this study was to clarify the effect of switching from SFC to FBC in patients with asthma not adequately controlled under the former treatment regimen.

METHODS

This was a prospective, multicenter, open-label, uncontrolled longitudinal study in 87 adult patients with an Asthma Control Questionnaire, 5-item version (ACQ5) score of greater than 0.75 under treatment with SFC 50/250μg one inhalation twice daily (bid). SFC was switched to FBC 4.5/160μg two inhalations bid. Study outcomes included ACQ5 score, peak expiratory flow (PEF), FEV(1), and fractional exhaled nitric oxide (FeNO) at the end of treatment period.

RESULTS

Eighty-three patients completed the study. ACQ5 scores improved and exceeded the clinically meaningful difference after 12 weeks of treatment and well-controlled asthma (ACQ5 score ≤0.75) was attained in 37 (44.6%) patients. Minimum and maximum PEF and FEV(1) values improved significantly, but not FeNO values, after switching from SFC to FBC.

CONCLUSIONS

Switching ICS/LABA combination therapy is a useful option in the management of asthma that is not optimally controlled.

In vitro evaluation of dry powder inhaler devices of corticosteroid preparations

BACKGROUND

Although investigations of the drug aerosols generated from inhaled corticosteroid (ICS) preparations and combined drug preparations provide basic information about inhalation therapy, many clinicians have one-sided data about the precision of drug aerosols from the manufacturer. The present study was conducted to analyze and compare the performances of dry powder inhaler (DPI) devices of ICS and combined drug preparations.

METHODS

The particle size of individual aerosols was measured according to the time-of-flight principle in terms of their aerodynamic diameter by using the aerodynamic particle sizer spectrometer Model 3321. Percent aerosolization was measured using only stage #0 and backup filters of the Andersen non-viable sampler model AN-200.

RESULTS

The particle size distribution of aerosols generated from a Turbuhaler™ and Twisthaler™ showed a mono-modal distribution of less than 5 μm. In contrast, Diskus™ showed a polydisperse distribution, ranging from 0.5 to 20 μm. The percentages of DPI preparations converted into aerosols with a particle size less than 11 μm at a suction flow rate of 28.3 L/min were 5.7-6.2% for Diskus, 37.5-47.0% for Turbuhaler, and 19.8% for Twisthaler. At a suction flow rate of 60 L/min, the conversion percentages for DPI preparations into aerosols with a particle size less than 7.6 μm were 5.9-7.5%, 78.2-86.7%, and 43.5%, respectively.

CONCLUSIONS

Because in vitro differences in the aerosolization among different DPI devices containing ICS and combined drug preparations were observed, prescribers of these preparations should consider whether the patients will benefit more from the treatment of the central airways versus the peripheral airways.

Consistency of dosing with a thermal aerosol generation system: in vitro and in vivo correlation

Dosing consistency and reproducibility are presented for a novel pharmaceutical inhaler technology based on a thermal condensation process. Two different device platforms producing thermally generated aerosols have been created and used in clinical studies with a number of different drug compounds. Because this approach does not rely on energy from the user to disperse the aerosol particles, aerosol production is reliable, reproducible and virtually user independent following actuation. Pharmacokinetic data from multiple clinical studies show rapid absorption, dose proportionality, and concentration levels and variability similar to intravenous injection. In addition, products used in clinical trials show excellent subject consistency with the vast majority of devices delivering greater than 90% of the loaded dose and little drug exhaled.

In vitro aerosol deposition in the oropharyngeal region for Staccato loxapine

BACKGROUND

The Staccato system employs a thermal vaporization technology to generate pure drug aerosols with a particle size optimized for alveolar deposition, leading to rapid absorption of the drug into the systemic circulation. Unlike most traditional aerosol-generation techniques, the particle size of the thermally generated aerosols is significantly affected by the airflow rate going through the device. The objective of this study was to determine the effects of flow rate and other operating conditions on predicted oropharyngeal and lung deposition when using the Staccato system.

METHODS

In vitro oropharyngeal deposition was measured at airflow rates of 15-80 L/min through the device. Oropharyngeal deposition was also measured for different inhalation profiles, different ambient temperatures and humidities, and device orientations. Deposition was measured using the Alberta geometry model, which was derived based on information available in the literature, CT scans of patients, and observations of living subjects.

RESULTS AND CONCLUSIONS

Deposition in the oropharyngeal geometry was consistently approximately 11% of the emitted dose throughout the entire range of flow rates. Such consistency in deposition was due to the fact that mass median aerodynamic diameter (MMAD) varied inversely as the square root of the flow rate, resulting in an approximately constant value for the inertial deposition parameter. Thus, an increase in flow rate, which would increase the momentum of a fixed particle size and generally lead to higher oropharyngeal deposition, was almost exactly counterbalanced by the accompanying decrease in MMAD. Results also showed that deposition in the oropharyngeal region was unaffected by other potentially relevant factors such as different airflow ramp rates, inhalation time, ambient temperature and relative humidity, and device orientations.

Dry powder inhalers (DPIs)--a review of device reliability and innovation

A wide range of dry powder inhaler (DPI) devices are currently available on the market to deliver drugs into lungs with a view to maximise drug delivery with low variability. DPIs also face numerous clinical challenges, particularly related to variable patient factors such as age, clinical condition and inspiratory flow. Due to the drug formulation and the design of devices, different DPIs do not show the same performance and manufacturers are taking a variety of device design approaches. The characteristics of an ideal DPI, recent innovations in powder formulation and device design are not universally reliable in terms of dose variability, clinical efficacy, user friendliness and economy. This mini review examines whether device reliability is more important than innovation. This study enables a comparison of the relative merits of optimising existing DPIs or seeking to develop novel devices.

Lung deposition and efficacy of inhaled formoterol in patients with moderate to severe COPD

BACKGROUND

Little is known about the impact of COPD on lung deposition of inhaled drugs and the relationship between lung-dose and response of pulmonary function measurements.

METHODS

Nineteen patients with varying degrees of COPD were randomized to inhale single doses of formoterol (Oxis) Turbuhaler 4.5, 9, 18, and 36 microg in a double blind, placebo-controlled, crossover design. Urinary excreted formoterol during 32 h was used to determine absolute lung deposition. Peak inspiratory flow (PIF) and inhaled volume (IV) were recorded to assess the patients' ability to use Turbuhaler. Efficacy was measured by spirometry, inspiratory capacity (IC), airway conductance (sG(AW)), and absolute lung volumes.

RESULTS

Mean pulmonary bioavailability of formoterol was about 24% of the nominal delivered dose after inhalation for the different treatments. No significant correlations between lung deposition and baseline FEV(1), PIF or IV were shown. All formoterol doses produced statistically significant increases in FEV(1), FVC, IC, and sG(AW) relative to placebo. Linear dose/response relationships were observed for these variables, with more narrow limits of the slopes for the lung-dose/response relationships than for the nominal-dose/response relationships. Moreover, 36 and 18 microg formoterol statistically significantly decreased functional residual capacity (FRC) and residual volume (RV) relative to placebo.

CONCLUSIONS

This study could not show any difference in lung deposition of formoterol inhaled via Turbuhaler between patients with moderate and severe COPD. Moreover, the effect of formoterol on various pulmonary function measurements were more closely related to lung deposition than the inhaled nominal dose.

Can all patients with COPD use the correct inhalation flow with all inhalers and does training help?

The inhalation rate is important when patients use an inhaler. Dry powder inhalers (DPIs) require an inhalation rate >30 L min(-1) whereas metered dose inhalers (MDIs) should be used at <90 L min(-1). Within the setting of a routine clinic, we have measured peak inhalation flows (PIF) of COPD patients when they used a Diskus (SDSK), Turbuhaler (STBH), Handihaler (SHAND) and MDI. Subjects were then randomised into trained (VT) and non-trained (NT) groups. One hundred and sixty-three patients with a mean (S.D.) age and % predicted FEV(1) of 72.5 (9.9) years and 47.8 (22.2)% completed the study. Of the patients, 4.9%, 14.2% and 57.0% inhaled <30 L min(-1) through SDSK, STHB and SHAND, respectively and 59.5% inhaled >90 L min(-1) with the MDI. Generally, the more severe the COPD, the slower was their PIF with all inhalers. The MDI PIF values in the VT group (n=84) post-training were significantly (p<0.001) slower but there was no change for the DPIs. Of the 55 VT patients inhaling >90 L min(-1) through the MDI only 7 (p<0.001) inhaled too fast post-training. Pre-training 3, 15 and 46 VT subjects inhaled <30 L min(-1) through the SDSK, STBH and SHAND and after training none, 5 and 26 did not inhale faster than this minimum required rate. Some COPD patients have problems achieving required PIFs through DPIs but training is useful to help some exceed the minimum required rate despite only small improvements. The patients found it easier to slow their PIF through the MDI.

The Diskus: a review of its position among dry powder inhaler devices

The use of dry powder inhalers (DPIs) to administer treatments for respiratory diseases has increased significantly in recent years. There is now a wide range of DPIs available that vary considerably in design, required operational techniques, output characteristics and drug delivery across a range of inhalation patterns. Different patient populations may find individual types of DPI easier to use correctly than others and selecting the right DPI for particular patient requirements will improve compliance with therapy. For example, some DPIs offer a greater resistance against inspirational flow rate than others which affects the total emitted dose and also fine particle mass of the aerosol released. An individual patient may therefore receive different amounts of drug when inhaling from different DPIs. Therefore, it is important that the prescriber is fully aware of the characteristics of the different types of DPI, so that he or she can prescribe the device that is most appropriate to an individual patient's needs. This review explores the characteristics of currently available DPIs and evaluates their efficacy and patient acceptability. The differences in output characteristics, ease of use and patient preferences between available devices is shown to affect treatment efficacy and patient compliance with therapy. Changing the DPI prescribed to a patient to a cheaper or generic device may therefore adversely affect disease control and thereby increase the cost of treatment.

Emitted dose estimates from Seretide Diskus and Symbicort Turbuhaler following inhalation by severe asthmatics

The dose emitted from dry powder inhalers may be inhalation flow-dependent. Using an ex vivo method, the Electronic Lung, we have measured the aerodynamic characteristics of the emitted dose for both active constituents from Seretide Diskus (salmeterol xinafoate 50 mcg; fluticasone propionate 500 mcg) and Symbicort Turbuhaler (formoterol 6 mcg; budesonide 200 mcg). Electronic inhalation profiles were collected from 20 severe asthmatics (mean PEFR 53% predicted) when they inhaled using a placebo Seretide Diskus and a placebo Symbicort Turbuhaler. These were replayed in the Electronic Lung with the respective active inhaler in situ. Mean(S.D.) peak inhalation flow rates (PIFR) through the Diskus and Turbuhaler were 94.7(32.9) and 76.8(26.2) l min(-1), respectively. From the Electronic Lung the Diskus inhalation profiles provided a mean(S.D.) fine particle dose (FPD) for fluticasone propionate and salmeterol of 20.4(4.8) and 18.4(4.4)% labelled dose. For Turbuhaler inhalation profiles the FPD was 23.1(12.9) and 20.7(11.1)% labelled dose for budesonide and formoterol, respectively. The linear (p < 0.001) relationships between FPD against PIFR for budesonide and formoterol were 3 (p = 0.002) and 2.8 (p = 0.007) times steeper than fluticasone propionate and salmeterol, respectively. The results highlight a more significant effect of inspiratory flow on variable dosage emission when using the Symbicort Turbuhaler compared with the Seretide Diskus.

High performance liquid chromatography assay method for simultaneous quantitation of formoterol and budesonide in Symbicort Turbuhaler

A sensitive and rapid high performance liquid chromatography method has been developed and used for the simultaneous determination of formoterol and budesonide in Symbicort Turbuhaler when assessing the aerodynamic characteristics of the emitted dose using Pharmacopoeial methods. This capability results in both time and cost saving. The mobile phase composition was acetonitrile-5 mM sodium dihydrogen orthophosphate, pH 3 (60: 40% v/v), and was passed at 1.5 ml min(-1) through a C18 column with a UV detection (wavelength 214 nm). The method was shown to give good analytical performance in terms of linearity, precision (using phenylpropanolamine as an internal standard), sensitivity and solution stability. The intra-day precision for both formoterol and budesonide were 0.75% and 1.11%, respectively (n = 10). The limit of quantitation for formoterol was 10 microgL(-1) and for budesonide was 120 microgL(-1), and the limit of detection were 3 and 30 microgL(-1), for both formoterol and budesonide, respectively. The method has been applied to determine the content of the emitted dose and the fine particle dose of Symbicort Turbuhaler.

Closer to an ???Ideal Inhaler??? with the Easyhaler??

The characteristics of an ideal inhaler are based around the design and formulation of the device, patient use and the clinical effect, together with concordance and patient preference. To ensure consistent drug delivery to the lungs, with regular adherence to the prescribed dosage regimen, it is essential that all these characteristics simultaneously interact to provide smooth and sustained therapeutic control affected only by the clinical status of the patient. The literature highlights that dose emission from an Easyhaler is fairly consistent irrespective of the inhalation technique used by patients of all age groups. Clinical studies have shown equivalence of this device to those frequently prescribed and that it is preferred by many patients. Although further research is required into the development of inhalation devices, the literature describing the Easyhaler dry powder inhaler indicates how an inhaler can closely meet the criteria for an ideal inhaler.

Regional lung deposition and bronchodilator response as a function of beta2-agonist particle size

RATIONALE

Aerosol particle size influences the extent, distribution, and site of inhaled drug deposition within the airways.

OBJECTIVES

We hypothesized that targeting albuterol to regional airways by altering aerosol particle size could optimize inhaled bronchodilator delivery.

METHODS

In a randomized, double-blind, placebo-controlled study, 12 subjects with asthma (FEV1, 76.8 +/- 11.4% predicted) inhaled technetium-99m-labeled monodisperse albuterol aerosols (30-microg dose) of 1.5-, 3-, and 6-microm mass median aerodynamic diameter, at slow (30-60 L/min) and fast (> 60 L/min) inspiratory flows. Lung and extrathoracic radioaerosol deposition were quantified using planar gamma-scintigraphy. Pulmonary function and tolerability measurements were simultaneously assessed. Clinical efficacy was also compared with unlabeled monodisperse albuterol (15-microg dose) and 200 microg metered-dose inhaler (MDI) albuterol.

RESULTS

Smaller particles achieved greater total lung deposition (1.5 microm [56%], 3 microm [50%], and 6 microm [46%]), farther distal airways penetration (0.79, 0.60, and 0.36, respective penetration index), and more peripheral lung deposition (25, 17, and 10%, respectively). However, larger particles (30-microg dose) were more efficacious and achieved greater bronchodilation than 200 microg MDI albuterol (deltaFEV1 [ml]: 6 microm [551], 3 microm [457], 1.5 microm [347], MDI [494]). Small particles were exhaled more (1.5 microm [22%], 3 microm [8%], 6 microm [2%]), whereas greater oropharyngeal deposition occurred with large particles (15, 31, and 43%, respectively). Faster inspiratory flows decreased total lung deposition and increased oropharyngeal deposition for the larger particles, with less bronchodilation. A shift in aerosol distribution to the proximal airways was observed for all particles.

CONCLUSIONS

Regional targeting of inhaled beta2-agonist to the proximal airways is more important than distal alveolar deposition for bronchodilation. Altering intrapulmonary deposition through aerosol particle size can appreciably enhance inhaled drug therapy and may have implications for developing future inhaled treatments.