The influence of inhaler selection on efficacy of asthma therapies

Experimental research on surface acoustic wave microfluidic atomization for drug delivery

This paper demonstrates that surface acoustic wave (SAW) atomization can produce suitable aerosol concentration and size distribution for efficient inhaled lung drug delivery and is a potential atomization device for asthma treatment. Using the SAW device, we present comprehensive experimental results exploring the complexity of the acoustic atomization process and the influence of input power, device frequency, and liquid flow rate on aerosol size distribution. It is hoped that these studies will explain the mechanism of SAW atomization aerosol generation and how they can be controlled. The insights from the high-speed flow visualization studies reveal that it is possible by setting the input power above 4.17 W, thus allowing atomization to occur from a relatively thin film, forming dense, monodisperse aerosols. Moreover, we found that the aerosol droplet size can be effectively changed by adjusting the input power and liquid flow rate to change the film conditions. In this work, we proposed a method to realize drug atomization by a microfluidic channel. A SU-8 flow channel was prepared on the surface of a piezoelectric substrate by photolithography technology. Combined with the silicon dioxide coating process and PDMS process closed microfluidic channel was prepared, and continuous drug atomization was provided to improve the deposition efficiency of drug atomization by microfluidic.

A Bayesian Framework to Assess the Usability of Dry Powder Inhalers in a Cohort of Asthma Adolescents in Italy

The useability of DPIs (dry powder inhalers) depends on several factors that are influenced by the patients’ subjectivity and objectivity. The short-form global usability score (S-GUS), a specific tool for the quick ranking and comparison in real life of an inhaler’s usability, was used to investigate six of the most prescribed DPIs (Breezhaler, Diskus, Ellipta, Nexthaler, Spiromax, and Turbohaler) in consecutive asthma patients aged <18 years. A Bayesian indirect comparison (IC) was carried out to merge all pairwise comparisons between the six DPIs. Thirty-three subjects participated: eighteen tested Breezhaler, Spiromax, Nexthaler, and Ellipta simultaneously, while fifteen tested Breezhaler, Spiromax, Diskus, and Turbohaler. The estimates of the S-GUS, by the IC model, allowed us to rank the DPIs by their degree of usability: Ellipta, Diskus, and Spiromax were classified as “good to pretty good” (S-GUS > 15), while Spiromax, Turbohaler, and Breezhaler were classified as “insufficient” (S-GUS < 15). The multidomain assessment is recommended in asthma adolescents in order to approximate the effective usability of different DPIs as best as possible. The S-GUS proves particularly suitable in current clinical practice because of the short time required for its use in adolescents.

Comparison between traditional and nontraditional add-on devices used with pressurised metered-dose inhalers

Add-on devices that are attached to metered-dose inhalers (MDIs) were introduced to improve aerosol delivery. The objective of this study was to determine the efficacy of drug delivery from an MDI when attached to different add-on devices at different inhalation volumes.

The total emitted dose (TED) of salbutamol was estimated for the MDI alone and the MDI connected to five different add-on devices (Able valved holding chamber, Tips-haler valved holding chamber, Aerochamber plus flow Vu valved holding chamber, Dolphin chamber, and a handmade water bottle spacer), at inhalation flow of 28.3 L·min⁻¹ with flow volume of 1, 2 and 4 L, assuming young child (aged <6 years), old child (>6 years) and adult inhalation volumes, respectively.

The TED% ranged between 84.1% and 87.2% at all inhalation volumes from the MDI alone, which was significantly greater than all MDI add-on device combinations (p<0.05). The TED% delivered to MDI sampling apparatus by a homemade water bottle spacer and Dolphin chamber, as non-antistatic add-on devices, ranged between 30.5% and 35.3%. However, washing these non-antistatic add-on devices with a light detergent before use improved their TED to range between 47.6% and 51.2%. Non-antistatic add-on devices had significantly lower TED (p<0.05) than that delivered by most antistatic add-on devices, which ranged from 51.3% to 71.6%.

This study suggests that antistatic add-on devices delivered much more aerosol than non-antistatic add-on devices. However, it may be advised to still use a non-antistatic add-on device, for the sake of solving the coordination problem, and wash it with light detergent before use to improve TED.

Antistatic add-on devices deliver much more aerosol from MDIs than non-antistatic add-on deviceshttps://bit.ly/3gSE5aR

The Global Usability Score Short-Form for the simplified assessment of dry powder inhalers (DPIs) usability

Background

The choice of the Dry Powder Inhaler (DPI) to prescribe is a critical issue. The estimation of DPIs usability depends on the objective assessment of several indices related to both subjective and objective determinants. The Global Usability Score (GUS) Questionnaire is a comprehensive tool usable for checking, comparing, and ranking inhalers' usability objectively in real life, but it takes some time to fill.

Aim

The aim of this study was to favour the quicker check of DPIs usability in clinical practice by means of a simplified short-form GUS (S-GUS) Questionnaire, while maintaining the high specificity and sensitivity of the original, extended version of the Questionnaire (O-GUS questionnaire).

Methods

The usability of the six most prescribed DPIs was assessed in 222 patients with persistent airway obstruction and needing long-term inhalation treatments. LASSO regression and multicollinearity test were used to select the subset of questions of the O-GUS questionnaire, with the highest information power. Each item was then scored using the corresponding coefficient in the linear regression (normalized at 50 as the O-GUS score). Agreement between the original and the short-form questionnaire was evaluated using the Cohen's kappa statistic (κ). The overall S-GUS values obtained for each DPI were then compared to those from the O-GUS, in the same patients, using a Bayesian indirect comparison (IC) model.

Results

After the statistical selection of the items mostly contributing to the overall score, the novel S-GUS questionnaire consists of twelve items only. Nine items are related to patients' opinion before DPIs handling, and three to the nurse's assessment after DPIs practicality. O-GUS and S-GUS score were strongly correlated (R²=0.9843, p<0.0001) and the usability score calculated for each DPI by means of the O- and of S- GUS overlapped almost completely (κ=84.5%, 95% CI 81.3% to 89.2%). Furthermore, S-GUS was much faster to complete than O-GUS (mean time 6.1 vs 23.4 minutes, p<0.001). Estimates of S-GUS, obtained from the IC model, allowed to propose a simple classification of usability: "good" by GUS values >25; "pretty good" by values ≤25≥15, and "insufficient" by values <15.

Conclusions

The S-GUS proves as much specific and suitable as the extended O-GUS questionnaire in measuring DPIs usability, while maintaining the same high sensitivity. As the time required for its use is quite shorter, S-GUS is also particularly suitable and helpful in current clinical practice.

Scope and limitations on aerosol drug delivery for the treatment of infectious respiratory diseases

The rise of antimicrobial resistance has created an urgent need for the development of new methods for antibiotics delivery to patients with pulmonary infections in order to mainly increase the effectiveness of the drugs administration, to minimize the risk of emergence of resistant strains, and to prevent patients reinfection. Since bacterial resistance is often related to antibiotic concentration, their pulmonary administration could eradicate strains resistant to the same drug at the concentration achieved through the systemic circulation. Pulmonary administration offers several advantages; it directly targets the site of the infection which allows the inhaled dose of the drug to be reduced compared to that administered orally or parenterally while keeping the same local effect. The review article is made with an objective to compile information about various existing modern technologies developed to provide greater patient compliance and reduce the undesirable side effect of the drugs. In conclusion, aerosol antibiotic delivery appears as one of the best technologies for the treatment of pulmonary infectious diseases and able to limit the systemic adverse effects related to the high drug dose and to make life easier for the patients.

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.

Instant velocity and consistency of emitted cloud change by the different levels of canister filling with Metered Dose Inhalers (MDIs), but not with Soft Mist Inhalers (SMIs): a bench study

Background

Inhalation is the preferred route for respiratory drug delivery, but several factors contribute to the variability of the respirable dose fraction. Instant velocity and the dynamic characteristics of the droplet cloud represent crucial factors. Aim was to measure and compare the instant velocity and the consistency of emitted cloud from five different MDIs (A - Salbutamol sulphate 100mcg, GSK; B - Salbutamol sulphate 100mcg, Valeas; C - Salmeterol xinafoate/Fluticasone propionate 25/125mcg, GSK; D - Formoterol fumarate/Bechlomethasone propionate 6/100mcg, Chiesi; E - Formoterol fumarate/Fluticasone dipropionate 5/125mcg, Mundipharma) and one SMI (Tiotropium bromide 5mcg, Boehringer Ingelheim), at different distance from the nozzle and canister filling.

Methods

Measurements were made at 90, 50, and 10% of canister filling, and at 5, 10, and 20 cm from the nozzle, for a total of 972 puffs. A high speed video photography protocol was adopted and high speed cameras (1.200 frames/sec.) were used. Data were acquired by means of specialized softwares. Temperature, humidity, and vibrations occurrence were strictly controlled during measurements. Statistics: Anova and p < 0.05 were accepted as the minimum significance level.

Results

MDIs generated different Instant velocities: MDI B generated the highest, while MDI A the lowest. As expected, velocity decreased in proportion to the distance from the nozzle. Except with MDI C, instant velocity decreased significantly over the first 50% of canister emptying, but dropped by >33% at 90% of emptying with all other MDIs (p < 0–037; p < 0.001; p < 0.005, and p < 0.001, respectively). Instant velocity was extremely lower (p < 0.001) and constant for all levels of canister filling (p = ns) with SMI. All MDIs had a very fast jet phase, ranging 0.01–0.03 s at 10 cm, and 0.03–0.05 s at 20 cm from the nozzle, without any significant difference from each other (p = ns). MDIs generated a cloud similarly tight (p = ns) at 10 and 20 cm from the nozzle, while it was extremely wider and constant with the SMI (p = 0–001). Also the cloud turbulence was minimized during the SMI emission.

Discussion and Conclusions

MDIs are characterized by a substantial variability in both their instant velocity and consistency of the emitted cloud at different levels of canister filling. SMI generates a much slower soft mist cloud which is constantly homogeneous and independent of canister emptying. These peculiarities assessed at bench are suggesting a higher dose consistency and a much more effective therapeutic performance also in real life.

Real-Life Outcomes for Patients with Asthma Prescribed Spacers for Use with Either Extrafine- or Fine-Particle Inhaled Corticosteroids

BACKGROUND

Spacers are often used with pressurized metered-dose inhalers (pMDIs) to eliminate the need for coordinating inhalation with actuation.

OBJECTIVE

To investigate the real-life effectiveness of spacers prescribed for use with either extrafine- or fine-particle inhaled corticosteroids (ICSs).

METHODS

This historical matched cohort study examined anonymous medical record data over 2 years (1-year baseline, 1-year outcome) for patients with asthma aged 12 to 80 years initiating ICSs by pMDI with or without prescribed spacer. We compared outcomes for spacer versus no-spacer arms, matched for key baseline and asthma-related characteristics, within 2 ICS cohorts: (1) extrafine-particle ICS (beclomethasone) and (2) fine-particle ICS (fluticasone). Effectiveness end points were compared using conditional regression methods.

RESULTS

Matched spacer and no-spacer arms of the extrafine-particle ICS cohort each included 2090 patients (69% females; median age, 46-47 years) and the 2 arms of the fine-particle ICS cohort each included 444 patients (67% females; median age, 45 years). With extrafine-particle ICS, we observed no significant difference between spacer and no-spacer arms in severe exacerbation rate (primary end point): adjusted rate ratio, 1.01 (95% CI, 0.83-1.23). With fine-particle ICS, the severe exacerbation rate ratio with spacers was 0.77 (0.47-1.25). Oropharyngeal candidiasis incidence was low and similar in spacer and no-spacer arms for both ICS cohorts.

CONCLUSIONS

We found no evidence that prescribed spacer devices are associated with improved asthma outcomes for extrafine- or fine-particle ICS administered by pMDI. These findings challenge long-standing assumptions that spacers should improve pMDI effectiveness and indicate the need for pragmatic trials of spacers in clinical practice.

Dry-powder inhalers in patients with persistent airflow limitation: usability and preference

BACKGROUND

Inhalation devices represent per sé critical factors because they can affect the therapeutic outcomes independently of the drug used. The role of patients' usability and preference (PUP) for Dry Powder Inhalers (DPIs) is high indeed because they can influence the extent of the adherence to treatment and the therapeutic outcomes. Aim of the study was to assess and compare the PUP of three different DPIs in out-patients with persistent airflow limitation due to asthma or COPD.

METHODS

The PUP of three different DPIs (Breezhaler; Genuair; Handihaler) were investigated by means of the Handling Questionnaire in out-patients with persistent airflow limitation needing an inhalation therapy. Patients had to report their preference before and after the nurse's instruction on the handling of each device. The nurse had also to note the critical steps during the patient's procedure for actuation; to count the number of attempts needed for actuating the device properly, and to measure the time (in sec.) required for these procedures. Data were collected up to three attempts per device.

STATISTICS

Welch test was used for normal distributed variables, while the Wilcoxon test for not normal distributed variables. The χ (2) test and the ANOVA test were also used. Univariate and multivariate regressions were also performed in order to investigate the effect of patients' characteristics and of technical differences of each device on their proper use.

RESULTS

Three hundred thirty-three consecutive out-patients (age range 55-58 years, and well matched for gender), with persistent airway limitation of different severity were investigated, suffering from bronchial asthma (n = 175) or from chronic obstructive pulmonary disease (COPD) (n = 158). In particular, 127 patients (38 %) tested the three DPIs, while 110 (33 %) tested Breezhaler and Genuair, and 96 (29 %) Breezhaler and Handihaler. More than 50 % of patients who tested all devices preferred the Genuair and perceived this device as the easiest to use. The nurse's judgement confirmed their opinion. When compared to the other two DPIs, Genuair proved the least problematic either according to the patients' judgement and to the nurse's opinion. Mean number of attempts aimed to achieving the first proper actuation was lower with Genuair than with Breezhaler and Handihaler (1.5 vs 2.5-2.6, p < 0.0001). Finally, Genuair also proved the easiest to use and the least problematic according to the nurse judgement (0.0001), the most easily learned (0.0001), and that one with a successful rate of more than 56 % at the first attempt. Breezhaler and Handihaler needed an average of about one additional attempt to be used properly (p < 0.0001), and their usability proved significantly more difficult (OR of successful rate between 0.15 and 0.17, p < 0.001). In general, older patients needed more attempts to perform their first proper inhalation; their successful rate was lower, and they needed more time to learn how to use devices properly: with Genuair these differences were minimized.

CONCLUSIONS

The possibility of grading objectively the performance of different DPIs in terms of their usability and therapeutic convenience in daily life represents a crucial operational opportunity to pursue. To note that a substantial discrepancy exists between the patients' belief "at glance" and the patients' effective usability with can be registered with some devices. From a general point of view, devices requiring less manual actions for their actuation confirmed their better usability and proper handling after less attempts. In particular, Genuair came out as the most preferred DPI also when several different aspects of preference and usability are assessed objectively and compared.

The Effect of Spacer Morphology on the Aerosolization Performance of Metered-Dose Inhalers

PURPOSE

Respiratory drug delivery has been attracted great interest for the past decades, because of the high incidence of pulmonary diseases. However, despite its invaluable benefits, there are some major drawbacks in respiratory drug delivery, mainly due to the relatively high drug deposition in undesirable regions. One way to improve the efficiency of respiratory drug delivery through metered-dose inhalers (MDI) is placing a respiratory spacer between the inhaler exit and the mouth. The aim of this study was to assess the effect of type and shape of spacer on the aerosolization performance of MDIs.

METHODS

A commercial Beclomethasone Dipropionate (BDP) MDI alone or equipped with two different spacer devices (roller and pear type) widely distributed in the world pharmaceutical market was used. The effect of spacers was evaluated by calculating aerosolization indexes such as fine particle fraction (FPF), mass median aerodynamic diameters (MMAD) and geometric standard deviation (GSD) using the next generation impactor.

RESULTS

Although one of the spacers resulted in superior outcomes than the other one, but it was not statistically significant.

CONCLUSION

The results confirmed that the type and shape of spacer did not substantially influence the aerosolization performance of MDIs.

Acceptability and preference of three inhalation devices assessed by the Handling Questionnaire in asthma and COPD patients

BACKGROUND

The patients' criteria of preference for inhalation devices can affect the extent of their adherence to treatment and outcomes. Aim of this study was to assess and compare the patients' preference and acceptability (PPA) for Breezhaler and Genuair (both Dry Powder Inhalers), and for Respimat (a Soft Mist Inhaler) in asthma and COPD out-patients by means of the Handling Questionnaire.

METHODS

The Handling Questionnaire is a validated instrument which allows the investigation of different domains of PPA; it also takes into account the patients' age and gender, together with their previous experience with the inhalation devices and their previous education approach to them. Differences in terms of preference, acceptance and usability were assessed by linear and logistic regressions in order to evaluate factors influencing the proper actuation.

RESULTS AND DISCUSSION

Data from 333 patients were collected: Genuair and Respimat were the most liked and perceived as the easiest to use at glance by patients, but also as the least problematic according to the patients' and nurse's judgments. Mean number of attempts for achieving the first effective actuation was the highest with Breezhaler (2.6 vs 1.6; p <0.0001). Linear regressions showed that longer the explanation, higher was the number of attempts to the first proper actuation (0.58 additional attempts every 10 s increase in the first explanation, p <0.0001). Devices requiring less manoeuvres for the actuation were used properly after less attempts (0.38 increase in the number of attempts every additional manoeuvres, p <0.0001). Respimat proved to be the most indicated in COPD patients since it was the most liked and its successful rate at first attempt was the highest. Logistic regressions confirmed these data. Previous experience with DPIs and/or MDIs did not affect the patient preference and acceptability, independently whether suffering from asthma or COPD.

CONCLUSIONS

Substantial differences are existing in patient's preference and acceptability for inhalation devices, mainly related to the handling and the understanding of the different devices.

Influences of cannula size and flow rate on aerosol drug delivery through the Vapotherm humidified high-flow nasal cannula system

OBJECTIVE

We investigated the in vitro inspired dose and particle size distribution of albuterol delivered by a vibrating mesh nebulizer through the Vapotherm (Stevensville, MD) humidified high-flow nasal cannula system.

DESIGN

Albuterol (2.5 mg/3 mL) was delivered by an Aeroneb Solo (Aerogen, Galway, Ireland) nebulizer that was connected via adaptor proximal to the nasal cannula and downstream from the Vapotherm 2000i. Albuterol was collected onto an inspiratory filter mounted to a breath simulator programmed with age-appropriate breathing patterns. Particle sizing was completed by cascade impaction. Albuterol was quantified using ultraviolet spectrometry. Measurements were made using varying flow rates through infant, pediatric, and adult nasal cannulae.

SETTING

Aerosol research laboratory.

MEASUREMENTS AND MAIN RESULTS

The inspired dose (percent of nominal dose) for each cannula size and flow rate was 2.5%, 0.8%, 0.4%, and 0.2% for the adult cannula at 5, 10, 20, and 40 L/min, respectively; 1.2%, 0.6%, 0.1%, and 0.0% for the pediatric cannula at 3, 5, 10, and 20 L/min, respectively; and 0.6%, 0.6%, and 0.5% for the infant cannula at 3, 5, and 8 L/min, respectively. Most (62-80%) of the loaded albuterol dose accumulated within the adaptor. For each cannula size, there was a significant decrease in the inspired dose with increasing flow rates, p = 0.026 (infant), p = 0.001 (pediatric), and p < 0.001(adult). The inspired dose increased with increasing cannula size for 5, 10, and 20 L/min (p = 0.007, p < 0.001, and p = 0.005, respectively). The mass median aerodynamic diameter for all trials was less than 5 µm.

CONCLUSION

The amount of albuterol delivered with the Vapotherm system using this model was lower than the amount expected for a clinical response for the majority of flow rates and cannula size combinations. Further studies are needed before routine use of aerosolized albuterol through a Vapotherm high-flow system can be recommended.

Salbutamol relative lung and systemic bioavailability of large and small spacers

Differences between the size and shape of spacers may affect the emitted dose and provide different effects when interchanged during routine use. Using a urinary pharmacokinetic method we have measured the relative lung and systemic bioavailability from urinary salbutamol excretion 30 min (USAL0.5) and 24 h (USAL24), respectively, after the inhalation of two 100-μg doses from a Ventolin Evohaler when used alone (MDI) and when attached to the Volumatic (VOL) or the Aerochamber Plus (AERO) spacers. The in-vitro properties of the emitted dose were determined. The mean (s.d.) USAL0.5 values following MDI, VOL and AERO (n = 13 volunteers) were 5.7 (1.9), 16.4 (8.2) and 14.8 (7.4) μg, respectively. VOL and AERO were significantly greater (P &lt; 0.001 and &lt; 0.01, respectively) than MDI. Comparison of VOL and AERO was similar with a mean ratio (90% confidence interval) of 108.2 (84.5, 138.6)%. USAL24 values between the three inhalation methods were similar. The values for the mean (s.d.) fine particle dose of two 100-μg doses emitted from MDI, VOL and AERO were 83.0 (6.8), 83.6 (4.6) and 73.6 (2.9) μg and the mass median aerodynamic diameters were 2.7 (0.03), 2.8 (0.07) and 2.9 (0.10) μm, respectively. The results showed that during routine use the Volumatic and the Aerochamber Plus spacers should provide similar lung and systemic delivery when attached to a Ventolin Evohaler.

Targeting drugs to the airways: The role of spacer devices

AIM

Spacer devices are inhalation aids of varying dimension and complexity, specifically designed to overcome problems with the use of pressurised metered dose inhalers (pMDIs). The aim of this review is to examine the current understanding about these inhalation devices and discuss their advantages and disadvantages.

METHODS

The pertinent literature concerning the characteristics and effects of spacers on delivery and lung deposition of inhaled medications, as well as their clinical efficacy in patients with reversible airway obstruction, is examined.

RESULTS

Spacers minimise problems of poor inhalation technique with pMDI, reduce oropharyngeal deposition and increase lung deposition. Spacers improve the clinical effect of inhaled medications, especially in patients unable to use a pMDI properly. Compared to both pMDIs and dry-powder inhalers, spacers may increase the response to beta-adrenergic bronchodilators, even in patients with correct inhalation technique. A pMDI plus spacer has proven to be viable lower cost alternative to the use of a nebuliser for delivering large bronchodilator doses in patients with severe acute asthma or chronic obstructive pulmonary disease. The use of large-volume spacers is recommended for delivering high doses of inhaled corticosteroids, and may permit a lower maintenance dose to be used.

CONCLUSION

pMDIs may be routinely fitted with a spacer, especially in situations where correct pMDI use is unlikely.

Design optimization of a novel pMDI actuator for systemic drug delivery

Pressurized metered dose inhalers (pMDIs) are the most widely prescribed and economical respiratory drug delivery systems. Conventional pMDI actuators-those based on "two-orifice-and-sump" designs-produce an aerosol with a reasonable respirable fraction, but with high aerosol velocity. The latter is responsible for high oropharyngeal deposition, and consequently low drug delivery efficiency. Kos' pMDI technology is based on a proprietary vortex nozzle actuator (VNA), an innovative actuator configuration that seeks to reduce aerosol plume velocity, thereby promoting deep lung deposition. Using VNA development as a case study, this paper presents a systematic design optimization process to improve the actuator performance through use of advanced optical characterization tools. The optimization effort mainly relied on laser-based optical diagnostics to provide an improved understanding of the fundamentals of aerosol formation and interplay of various geometrical factors. The performance of the optimized VNA design thus evolved was characterized using phase Doppler anemometry and cascade impaction. The aerosol velocities for both standard and optimized VNA designs were found to be comparable, with both notably less than conventional actuators. The optimized VNA design also significantly reduces drug deposition in the actuator as well as USP throat adapter, which in turn, leads to a significantly higher fine particle fraction than the standard design (78 +/- 3% vs. 63 +/- 2% on an ex valve basis). This improved drug delivery efficiency makes VNA technology a practical proposition as a systemic drug delivery platform. Thus, this paper demonstrates how advanced optical diagnostic and characterization tools can be used in the development of high efficiency aerosol drug delivery devices.

Comparable long-term safety and efficacy of a novel budesonide/formoterol pressurized metered-dose inhaler versus budesonide/formoterol Turbuhaler in adolescents and adults with asthma

Budesonide/formoterol in one inhaler is an established therapy for asthma and chronic obstructive pulmonary disease. The long-term safety and efficacy profile of a novel hydrofluoroalkane (HFA) pressurized metered-dose inhaler (pMDI) formulation of budesonide/formoterol was compared with that of budesonide/formoterol in a dry powder inhaler (DPI; Turbuhaler). This multinational, 52-week, randomized, open, parallel-group study included patients aged > or = 12 years with asthma who had a forced expiratory volume in 1s (FEV1)> or = 50% of predicted normal; all patients used inhaled corticosteroids (400-1200 microg/day) and needed additional short-acting beta 2-agonist therapy. Patients were randomized to receive budesonide/formoterol pMDI or DPI 160/4.5 microg, two inhalations twice daily. Safety endpoints included assessment of adverse events and laboratory parameters. Efficacy endpoints included change from baseline in FEV1 and time to first severe asthma exacerbation. Overall, 673 patients (446pMDI, 227DPI) were included. There were no clinically significant differences between treatment groups in the nature, incidence or severity of adverse events or laboratory parameters. The number of patients experiencing adverse events was comparable in the pMDI (332/446 [74%]) and DPI (175/227 [77%]) groups; the most commonly reported adverse event was upper respiratory tract infection. The proportion of patients discontinuing as a result of adverse events was low in both groups (pMDI 12/446 [3%], DPI 2/227 [1%]). Lung function was improved to a similar extent in both groups and there was no detectable difference in time to first severe asthma exacerbation. The novel HFA pMDI formulation of budesonide/formoterol is an equally well tolerated and effective treatment for adults and adolescents with asthma as the budesonide/formoterol DPI.

Paediatric pulmonary drug delivery: considerations in asthma treatment

Aerosol therapy, the preferred route of administration for glucocorticosteroids and short-acting beta(2)-adrenergic agonists in the treatment of paediatric asthma, may be given via nebulisers, metered-dose inhalers and dry powder inhalers. For glucocorticosteroids, therapy with aerosolised medication results in higher concentrations of drug at the target organ with minimal systemic side effects compared with oral treatments. The dose of drug that reaches the airways in children with asthma is dependent on both the delivery device and patient-related factors. Factors that affect aerosol drug delivery are reviewed briefly. Advantages and disadvantages of each device and device-specific factors that influence patient preferences are examined. Although age-based device recommendations have been made, the optimal choice for drug delivery is the one that the patient or caregiver prefers to use, can use correctly and is most likely to use consistently.

Respimat Soft Mist inhaler versus hydrofluoroalkane metered dose inhaler: patient preference and satisfaction

INTRODUCTION

In addition to offering favorable pharmaceutical performance, an ideal inhaler should be well accepted by patients, as this may facilitate compliance. We report a study that specifically assessed inhaler preference in patients with obstructive lung disease after treatment with ipratropium bromide/fenoterol hydrobromide (Berodual delivered via either Respimat Soft Mist Inhaler (SMI) or hydrofluoroalkane metered dose inhaler (HFA-MDI).

METHODS

Patients with COPD, asthma or mixed disease were randomized to receive ipratropium bromide/fenoterol hydrobromide 20/50 microg via Respimat SMI or 40/100 microg via HFA-MDI for 7 weeks each, in a crossover design. Patients were trained in inhaler use and given < or =5 attempts to demonstrate satisfactory technique. At the end of each treatment period, patients completed a 15-item satisfaction questionnaire, and inhaler technique was re-tested. On study completion, patients were asked which inhaler they preferred and they rated their willingness to continue using each inhaler. Clinical efficacy outcomes were measured by diary card to check whether switching inhaler affected efficacy.

RESULTS

In total, 245 patients were randomized and 224 used both inhalers within their respective treatment periods. Of 201 patients expressing a preference, 162 (81%) preferred Respimat SMI and 39 (19%) preferred HFA-MDI (p < 0.001). Patients would rather continue using Respimat SMI than HFA-MDI (p < 0.001). Mean scores for 13 of the 15 satisfaction questions were significantly higher for Respimat SMI than HFA-MDI (p < 0.05); in addition, the total score was also significantly higher for Respimat SMI (p < 0.001). Most patients (217/224; 97%) were judged to have good technique with Respimat SMI after 7 weeks' use. Differences in efficacy measures between the devices were not significant.

CONCLUSION

These data indicated that a large majority of patients preferred Respimat SMI to HFA-MDI.

Propellant-driven metered-dose inhalers for pulmonary drug delivery

The current market for pulmonary drug delivery is at a bottleneck. The therapeutic advantages of inhalation aerosols, and the potential for the lungs as a route for systemically acting drugs, vaccines and gene therapeutic agents, have resulted in a rapid growth of the industry. Alongside this, the environment of inhaler design and formulation has changed markedly in recent years. Environmental concerns over propellants, the commercial success of dry powder inhalers, and the apparent lack of advancement of propellant-driven metered-dose inhalers (pMDIs) has led to a less clear future for these devices. This review critically assesses these pressures and also potential opportunities for the pMDI. It is proposed that the future role of pMDIs will be determined by several important forces that can be classified under 'technology development' or 'market climate' categories. Technology development forces will be strengthened by the ability of the industry to have a systematic understanding of mechanisms of spray formation, perform subsequent and continued device and formulation advances, and a focus on all patient groups: particularly paediatric and geriatric populations. The ability to succeed in these areas will be largely determined by the willingness to invest in fundamental research of pMDI technologies.