The rejuvenated pressurised metered dose inhaler

Inhalable aerosol microparticles with low carrier dosage and high fine particle fraction prepared by spray-freeze-drying

Co-suspension drug-loading technology, namely Aerosphere™, can improve fine particle fraction (FPF) and delivered dose content uniformity (DDCU). However, because of its poor drug-loading efficacy, the phospholipid carrier dosage in Aerosphere™ is usually dozens of times greater than that of the drug, resulting in a high material cost and blockage of the actuator. In this study, spray-freeze-drying (SFD) technology was used to prepare inhalable distearoylphosphatidylcholine (DSPC)-based microparticles for pressurized metered-dose inhalers (pMDI). Water-soluble, low-dose formoterol fumarate was used as an indicator to evaluate the aerodynamic performance of the inhalable microparticles. Water-insoluble, high-dose mometasone furoate was used to investigate the effects of drug morphology and drug-loading mode on the drug delivery efficiency of the microparticles. The results demonstrated that DSPC-based microparticles prepared using the co-SFD technology not only achieved higher FPF and more consistent delivered dose than those of drug crystal-only pMDI, but the amount of DSPC was also reduced to approximately 4% of that prepared using the co-suspension technology. This SFD technology may also be used to improve the drug delivery efficiency of other water-insoluble and high-dose drugs.

Recent advances in dosage form design for the elderly: a review

INTRODUCTION

With the increase in the elderly population and the prevalence of multiple medical conditions, medication adherence, and efficacy have become crucial for the effective management of their health. The aging population faces unique challenges that need to be addressed through advancements in drug delivery systems and formulation technologies.

AREAS COVERED

The current review highlights the recent advances in dosage form design for older individuals, with consideration of their specific physiological and cognitive changes. Various dosage forms, such as modified-release tablets/capsules, chewable tablets, and transdermal patches, can be tailored to meet the specific needs of elderly patients. Advancements in drug delivery systems, such as nanotherapeutics, additive manufacturing (three-dimensional printing), and drug-food combinations, improve drug delivery and efficacy and overcome challenges, such as dysphagia and medication adherence.

EXPERT OPINION

Regulatory guidelines and considerations are crucial in ensuring the safe utilization of medications among older adults. Important factors to consider include geriatric-specific guidelines, safety considerations, labeling requirements, clinical trial considerations, and adherence and accessibility considerations.

Fixed-dose combination fluticasone/formoterol for asthma treatment in a real-world setting: meta-analysis of exacerbation rates and asthma control

BACKGROUND

Treatment guidelines for asthma management are derived almost exclusively from the results of controlled clinical trials undertaken in carefully selected patient populations; meaning that their outcomes may not reflect the true performance of treatments when used in general daily medical practice. The aim of this meta-analysis was to combine the results of observational studies investigating the fluticasone propionate/formoterol (FP/FORM) fixed-dose combination in real-world asthma patients.

METHODS

A systemic literature review was completed in March 2019 using the PubMed database. We identified 394 studies. Five studies, which included a total of 4756 patients treated with FP/FORM, were judged eligible and included in the meta-analysis.

RESULTS

The estimated severe asthma exacerbation rate was 11.47% (95% CI, 5.8 to 18.72%), calculated from the random effect model. A sensitivity analysis excluding 2 studies (one was an outlier, and the exacerbation rate for the studied treatment alone could not be determined in the other) showed a 7.04% rate of severe asthma exacerbations. The estimated relative risk of the incidence of severe asthma exacerbations was 0.323 (95% CI, 0.159 to 0.658). The estimated asthma control rate was 60.6% (95% CI, 55.7% to 65.6%). The odds of achieving asthma control significantly increased by FP/FORM compared with pre-study conditions (estimated odds ratio: 2.214 [95% CI, 1.292 to 3.795]; p < 0.001).

CONCLUSIONS

The findings of this meta-analysis confirm the effectiveness of FP/FORM for the treatment of asthma patients in a real-world setting beyond the limitations of RCTs.

Increasing the fine particle fraction of pressurised metered dose inhaler solutions with novel actuator shapes

In this paper we demonstrate that the use of multiple orifices can improve the fine particle fraction (FPF) of pressurised metered-dose inhaler solution formulations by up to 75% when compared to a single orifice with an equivalent cross sectional area (p<0.05). While prior work has relied on metal actuator components, improvements in micro injection moulding and micro drilling now make it possible to mass produce novel orifice shapes to achieve similar FPF gains in plastic parts, with orifice diameters less than 0.2 mm. The ability to create internal features inside the actuator is also demonstrated. We show through in vitro high speed imaging that twin orifice sprays merge quickly and act as a single, modified plume. We also show for the first time that FPF and fine particle dose (FPD) are strongly correlated with the distance at which the plume velocity decays to half its initial value (R²=0.997 and 0.95 respectively). When plume velocity & FPF are increased, mouthpiece deposition decreases. This suggests that while smaller orifices produce more fine particles, higher sustained plume velocities also entrain more of the fine particles produced at the periphery of the spray due to increased shear. The effect occurs within the mouthpiece and is thus unlikely to alter the flow field in the upper airway.

Comparing the efficacy and safety of formoterol/budesonide pMDI versus its mono-components and other LABA/ICS in patients with asthma

INTRODUCTION

Pressurised metered dose inhalers (pMDIs) are effective drug delivery devices prescribed in obstructive airway diseases due to their convenience, portability, ease of enabling multiple doses in a single formulation, and storage in any orientation. For the management of asthma, the fixed-dose combination of a long-acting β₂-agonist (LABA) and an inhaled corticosteroid (ICS) has been recommended by Global Initiative for Asthma guideline as a preferred treatment option for patients who are uncontrolled with only ICS doses. One of the available LABA/ICS combinations is the formoterol/budesonide (FB).

AREAS COVERED

This article systematically reviews the efficacy and safety of the FB pMDI compared with the FB dry powder inhaler (DPI), individual mono-components (formoterol and budesonide) or salmeterol/fluticasone (SF) combination in the treatment of asthma among paediatric and adult patients. PubMed was searched with the string: ''((Budesonide) AND Formoterol) AND ((((pMDI) OR MDI) OR Pressurised Metered-dose inhaler) OR Metered-dose inhaler)'', in ALL fields. Screening of all the articles was done till February 2020. We have included 24 articles from the total of 142 hits received.

CONCLUSIONS

The FB pMDI is efficacious for the long-term management of asthma in patients 6 years of age and above. It has been shown to improve lung function and asthma control, and to reduce daytime and night-time symptoms, the number of rescue medication doses and asthma exacerbations. It also showed rapid onset of bronchodilatory effect with a dose-response relationship that allows patients to utilise it as a Single Maintenance And Reliever Therapy (SMART) regimen.

Drug Delivery Devices for Inhaled Medicines

Historically, the inhaled route has been used for the delivery of locally-acting drugs for the treatment of respiratory conditions, such as asthma, COPD, and airway infections. Targeted delivery of substances to the lungs has some key advantages over systemic administration, including a more rapid onset of action, an increased therapeutic effect, and, depending on the agent inhaled, reduced systemic side effects since the required local concentration in the lungs can be obtained with a lower dose. Fortunately, when designed properly, inhaled drug delivery devices can be very effective and safe for getting active agents directly to their site of action.

High-Speed Laser Image Analysis of Plume Angles for Pressurised Metered Dose Inhalers: The Effect of Nozzle Geometry

The aim of this study is to investigate aerosol plume geometries of pressurised metered dose inhalers (pMDIs) using a high-speed laser image system with different actuator nozzle materials and designs. Actuators made from aluminium, PET and PTFE were manufactured with four different nozzle designs: cone, flat, curved cone and curved flat. Plume angles and spans generated using the designed actuator nozzles with four solution-based pMDI formulations were imaged using Oxford Lasers EnVision system and analysed using EnVision Patternate software. Reduced plume angles for all actuator materials and nozzle designs were observed with pMDI formulations containing drug with high co-solvent concentration (ethanol) due to the reduced vapour pressure. Significantly higher plume angles were observed with the PTFE flat nozzle across all formulations, which could be a result of the nozzle geometry and material's hydrophobicity. The plume geometry of pMDI aerosols can be influenced by the vapour pressure of the formulation, nozzle geometries and actuator material physiochemical properties.

Pressurised metered dose inhaler-spacer technique in young children improves with video instruction

The importance of good device technique to maximise delivery of aerosolised medications is widely recognised. Pressurised metered dose inhaler (pMDI)-spacer technique was investigated in 122 children, aged 2-7 years, with asthma. Eight individual steps of device technique were evaluated before and after viewing an instructional video for correct device technique. Video measurements were repeated every three months for nine months. Device technique improved directly after video instruction at the baseline study visit (p < 0.001) but had no immediate effect at subsequent visits. Additionally, pMDI-spacer technique improved with successive visits over one year for the group overall as evidenced by increases in the proportion of children scoring maximal (p = 0.02) and near-maximal (p = 0.04) scores.

CONCLUSION

Repeated video instruction over time improves inhaler technique in young children.

WHAT IS KNOWN

• Correct device technique is considered essential for sufficient delivery of inhaled medication. • Poor inhaler use is common in young asthmatic children using pressurised metered dose inhalers and spacers. What is New: • Video instruction could be used as a strategy to improve device technique in young children.

The Evolution of Pressurized Metered-Dose Inhalers from Early to Modern Devices

Pressurized metered-dose inhalers (pMDIs) are sometimes viewed as old-fashioned and as having been superseded by dry powder inhalers (DPIs). Here, we review the technological advances that characterize modern pMDIs, and consider how they can influence the effectiveness of drug delivery for patients with asthma and chronic obstructive pulmonary disease. Compared with old chlorofluorocarbon (CFC)-based inhalers, many hydrofluoroalkane (HFA)-driven pMDIs have more favorable plume characteristics such as a reduced velocity and a higher fine particle fraction; together, these advances have resulted in the development of pMDIs with reduced oropharyngeal deposition and increased lung deposition. In addition, the plume from many HFA-pMDIs is warmer, which may facilitate their use by patients; moreover, devices are equipped with dose counters, which improves their reliability. As well as reviewing the technological advances of pMDIs, we also discuss the importance of individualizing inhaler therapies to each patient by accounting for their personal preferences and natural breathing patterns. Because pMDIs and DPIs differ considerably in their handling characteristics, matching the right inhaler to the right patient is key to ensuring effective therapy and good compliance. Finally, the majority of patients can be trained successfully in the correct use of their pMDI; training and regular monitoring of inhalation technique are essential prerequisites for effective therapy. While the 'ideal inhaler' may not exist, pMDIs are an effective device option suitable for many patients. pMDIs, together with other types of devices, offer opportunities for the effective individualization of treatments.

Fluorescence lifetime imaging of optically levitated aerosol: a technique to quantitatively map the viscosity of suspended aerosol particles

A technique to measure the viscosity of stably levitated single micron-sized aerosol particles.

Generation of tailored aerosols for inhalative drug delivery employing recent vibrating-mesh nebulizer systems

Direct drug delivery to the lungs is considered the gold standard for the treatment of a variety of respiratory diseases, owing to the increased therapeutic selectivity of the inhalative approach. Airborne formulations with defined size characteristics are required to improve the deposition pattern within the airways. In this respect, different nebulizer systems have been conceived, which has enabled the generation of respirable medicament mists. Here, vibrating-mesh technology revealed significant potential to overcome the main shortcomings associated with ‘traditional’ devices. Tailored orifice dimensions and defined formulation characteristics are of special interest for the generation of suitable aerosol droplets for inhalative purposes. Ongoing developments in device and formulation design will optimize the clinical outcome of inhalative drug delivery under application of vibrating-mesh technology.

Comparing the efficacy and safety of salmeterol/fluticasone pMDI versus its mono-components, other LABA/ICS pMDIs and salmeterol/fluticasone Diskus in patients with asthma

INTRODUCTION

Pressurized metered dose inhalers (pMDIs) are evolving to be a very effective drug delivery option in patients with airway diseases. They offer comparable lung deposition and reduced oropharyngeal deposition similar with the dry powder inhalers. As recommended by the Global Initiative for Asthma guidelines, the ideal maintenance treatment for asthma is a combination of long acting β2-agonists (LABAs) and inhaled corticosteroids (ICSs). One of the available LABA/ICS combinations is the salmeterol/fluticasone propionate combination (SFC) and a plethora of evidence supports its clinical efficacy and safety.

AREAS COVERED

This article focuses on the SFC hydrofluroalkane pMDI and compares the efficacy and tolerability with salmeterol and fluticasone given individually, and with other fixed-dose combinations namely formoterol/fluticasone, formoterol/beclometasone and formoterol/mometasone furoate, all delivered via pMDI. Also discussed is the efficacy and tolerability of the SFC delivered via a pMDI, as compared to the SFC via Diskus.

EXPERT OPINION

pMDIs play an important role in inhalation therapy given the low price, low maintenance and convenience of use. LABA/ICS combinations are the preferred choice of medication for asthma treatment and will remain the mainstay for the decades to come. In our opinion, pMDI should be the choice of device to administer LABA/ICS maintenance therapy, as it is already being used by the patients for reliever therapy, which may eventually improve patient adherence and compliance.

Developing an in vitro understanding of patient experience with hydrofluoroalkane-metered dose inhalers

As a result of the Montreal Protocol on Substances that Deplete the Ozone Layer, manufacturers of metered dose inhalers began reformulating their products to use hydrofluoroalkanes (HFAs) as propellants in place of chlorofluorocarbons (CFCs). Although the new products are considered safe and efficacious by the US Food and Drug Administration (FDA), a large number of complaints have been registered via the FDA's Adverse Events Reporting System (FAERS)-more than 7000 as of May 2013. To develop a better understanding of the measurable parameters that may, in part, determine in vitro performance and thus patient compliance, we compared several CFC- and HFA-based products with respect to their aerodynamic performance in response to changes in actuator cleaning interval and interactuation delay interval. Comparison metrics examined in this study were: total drug delivered ex-actuator, fine particle dose (<5 μm), mass median aerodynamic diameter, plume width, plume temperature, plume impaction force, and actuator orifice diameter. Overall, no single metric or test condition distinguishes HFA products from CFC products, but, for individual products tested, there were a combination of metrics that differentiated one from another.

Advances in device and formulation technologies for pulmonary drug delivery

Inhaled pharmaceuticals are formulated and delivered differently according to the therapeutic indication. However, specific device-formulation coupling is often fickle, and new medications or indications also demand new strategies. The discontinuation of chlorofluorocarbon propellants has seen replacement of older metered dose inhalers with dry powder inhaler formulations. High-dose dry powder inhalers are increasingly seen as an alternative dosage form for nebulised medications. In other cases, new medications have completely bypassed conventional inhalers and been formulated for use with unique inhalers such as the Staccato® device. Among these different devices, integration of software and electronic assistance has become a shared trend. This review covers recent device and formulation advances that are forming the current landscape of inhaled therapeutics.

The effect of altitude on inhaler performance

The purpose of the study is to understand the effect of altitude on the performance of selected pressurized metered dose inhalers (pMDIs) and dry powder inhalers (DPIs). A testing apparatus that created consistent breath profiles through the Alberta Idealized Throat was designed to test five pMDIs and two DPIs at altitudes of 670, 2450, 3260, and 4300 m. Both gravimetric and chemical assays were conducted to determine the in vitro lung dose. Additionally, spray duration and shot weight for pMDIs and device resistance for DPI were measured. There was no significant change in in vitro lung dose for any of the pMDIs tested. Shot weight and spray duration were unaffected. The device resistance of the DPIs decreased with increasing altitude and was successfully modeled as a function of ambient pressure. The in vitro lung dose of both DPIs showed no significant change when operated with an inhaler pressure drop of 4 kPa, but for the Bricanyl(®) Turbuhaler(®), a significant decrease occurred when matching the volumetric inspiratory flow rate to that of the baseline altitude.

Improving inhaler technique, adherence to therapy and the precision of dosing: major challenges for pulmonary drug delivery

INTRODUCTION

The inhaled route has many advantages, but requires the patient to use, and to master the use of, an inhaler device. Poor inhaler technique and non-adherence to therapy lead to a highly variable lung dose in clinical practice, with subsequent loss of clinical efficacy and wastage of economic resources.

AREAS COVERED

This paper discusses problems of poor inhaler technique, non-adherence to inhaler therapy, other issues relating to the precision of dose delivery, the consequences of these problems and how they can be addressed.

EXPERT OPINION

The precision of dosing by the pulmonary route can be improved by appropriate choice of inhaler device and by education. It is vital to educate patients about their disease, about the importance of taking prescribed medications and about correct inhaler use. One-on-one sessions with healthcare professionals probably represent the most effective educational method. For some drugs and patient groups, inhalers containing small microprocessors may also be used to control inhalation technique, and hence, to obtain a more reproducible lung dose. As the range of drugs delivered by inhalation increases, the need for correct inhaler technique, adherence to therapy and precise dosing becomes more and more important.

Factors affecting the stability and performance of ipratropium bromide; fenoterol hydrobromide pressurized-metered dose inhalers

The aim of the study was to investigate the factors affecting the stability and performance of ipratropium bromide and fenoterol hydrobromide in a pressurized-metered dose inhaler (pMDI). A factorial design was applied to investigate the effects of three parameters (propellant, water, and ethanol) on the performance of 27 designed formulations of a solution-based pMDI. The formulations that contained a hydrofluoroalkane (HFA) propellant lower than 72% v/v and an ethanol concentration higher than 27% v/v remained as clear solutions. Nine formulations that contained the HFA propellant higher than 74% v/v precipitated. The results indicated that it was not only the HFA propellant content of the formulations that was related to the formulation instability but also ethanol content. Only six formulations from the 18 formulations, that did not precipitate, produced drug contents that were within the acceptable range (80-120%). These six formulations generated aerosols with mass median aerodynamic diameters (MMAD) of approximately 2 μm with a fine particle fraction (FPF; particle size, <6.4 μm) between 45% and 52%. The MMAD and FPF did not change significantly after 6 months of storage (P > 0.05).

Inhaler devices for patients with COPD

Chronic obstructive pulmonary disease (COPD) continues to be associated with increased morbidity and mortality risk in spite of updated guidelines and a better understanding of this condition. Progressive airflow limitation and resultant hyperinflation-the respiratory hallmarks of this complex and often under-diagnosed disease-can be treated with pharmacotherapies emitted via nebulizers, pressurized metered-dose inhalers, dry powder inhalers, or a Soft Mist inhaler. Pharmaceutical company proprietary issues, technological innovations, and societal pressure have expanded the list of available inhalers, with a limited range of medications available for any one device. Each device has different operating and maintenance instructions, and successful use of a given drug/device combination requires that patients understand, maintain, and use each of their devices properly in order to ensure consistent and optimal pulmonary drug delivery. Clinicians are faced with a range of physical and psychosocial issues unique to each patient with COPD that must be overcome in order to match a suitable inhaler to the individual. Improved drug delivery afforded by next-generation inhalers, coupled with an awareness of device-specific and patient-specific variables affecting inhaler use, may improve clinical outcomes in the treatment of COPD.

Towards the bioequivalence of pressurised metered dose inhalers 2. Aerodynamically equivalent particles (with and without glycerol) exhibit different biopharmaceutical profiles in vitro

Two solution-based pressurised metered dose inhaler (pMDI) formulations were prepared such that they delivered aerosols with identical mass median aerodynamic diameters, but contained either beclomethasone dipropionate (BDP) alone (glycerol-free formulation) or BDP and glycerol in a 1:1 mass ratio (glycerol-containing formulation). The two formulations were deposited onto Calu-3 respiratory epithelial cell layers cultured at an air interface. Equivalent drug mass (∼1000ng or ∼2000ng of the formulation) or equivalent particle number (1000ng of BDP in the glycerol-containing versus 2000ng of BDP in the glycerol-free formulation) were deposited as aerosolised particles on the air interfaced surface of the cell layers. The transfer rate of BDP across the cell layer after deposition of the glycerol-free particles was proportional to the mass deposited. In comparison, the transfer of BDP from the glycerol-containing formulation was independent of the mass deposited, suggesting that the release of BDP is modified in the presence of glycerol. The rate of BDP transfer (and the extent of metabolism) over 2h was faster when delivered in glycerol-free particles, 465.01ng±95.12ng of the total drug (20.99±4.29%; BDP plus active metabolite) transported across the cell layer, compared to 116.17ng±3.07ng (6.07±0.16%) when the equivalent mass of BDP was deposited in glycerol-containing particles. These observations suggest that the presence of glycerol in the maturated aerosol particles may influence the disposition of BDP in the lungs.

Cosuspensions of microcrystals and engineered microparticles for uniform and efficient delivery of respiratory therapeutics from pressurized metered dose inhalers

Engineered porous phospholipid microparticles with aerodynamic diameters in the respirable range of 1-2 μm were cosuspended in 1,1,1,2-tetrafluoroethane, a propellant, with microcrystals of glycopyrrolate, formoterol fumarate dihydrate, or Mometasone furoate-three drugs with different solubilities in the propellant, and different physical, chemical, and pharmacological attributes. The drug microcrystals were added individually, in pairs, or all three together to prepare different cosuspensions, contained in a pressurized metered dose inhaler (pMDI). The drug microcrystals irreversibly associated with the porous particles, and the resultant cosuspensions possessed greatly improved suspension stability compared with suspensions of drug microcrystals alone. In general, all cosuspensions showed efficient dose delivery of the drugs, with fine particle fractions of more than 60% for a wide range of doses, including those as low as 300 ng per inhaler actuation. In the cosuspension pMDIs, comparable fine particle fractions were delivered for all tested drugs, whether or not they were emitted from an inhaler containing one, two, or three drugs. We demonstrate that the cosuspension approach solves at least three long-standing problems in the clinical development of pMDI-based products: (1) dose and drug dependent delivery efficiency, (2) inability to formulate dose strengths below 1 μg to fully explore drug efficacy and safety, and (3) combination suspensions delivering a different fine particle fraction than individual drug suspensions.

Surfactants: their critical role in enhancing drug delivery to the lungs

For local lung conditions and diseases, pulmonary drug delivery has been widely used for more than 50 years now. A more recent trend involves the pulmonary route as a systemic drug-delivery target. Advantages such as avoidance of the gastrointestinal environment, different enzyme content compared with the intestine, and avoidance of first-pass metabolism make the lung an alternative route for the systemic delivery of actives. However, the lung offers barriers to absorption such as a surfactant layer, epithelial surface lining fluid, epithelial monolayer, interstitium and basement membrane, and capillary endothelium. Many delivery strategies have been developed in order to overcome these limitations. The use of surfactants is one of these approaches and their role in enhancing pulmonary drug delivery is reviewed in this article. A systematic review of the literature relating to the effect of surfactants on formulations for pulmonary delivery was conducted. Specifically, research reporting enhancement of in vivo performance was focused on. The effect of the addition of surfactants such as phospholipids, bile salts, non-ionic, fatty acids, and liposomes as phospholipid-containing carriers on the enhancement of therapeutic outcomes of drugs for pulmonary delivery was compiled. The main use attributed to surfactants in pulmonary drug delivery is as absorption enhancers by mechanisms of action not yet fully understood. Furthermore, surfactants have been used to improve the delivery of inhaled drugs in various additional strategies discussed herein.

Novel cosuspension metered-dose inhalers for the combination therapy of chronic obstructive pulmonary disease and asthma

Pressurized metered dose inhaler is the most common inhaled dosage form, ideally suited for delivering the highly potent compounds that medicinal chemists typically discover for respiratory therapeutic targets. The clinical benefit of combination therapy for asthma and chronic obstructive pulmonary disease has been well established, and many of the new discovery candidates are likely to be studied in the clinic as combination drugs even at early stages of development. We present a novel pressurized metered dose inhaler formulation approach to enable consistent aerosol performance of a respiratory therapeutic whether it is emitted from a single-, double- or triple-therapy product. This should enable rapid nonclinical and clinical assessment whether alone or in combination with other drugs, without the challenge of in vitro performance dissimilarity across product types.

ProAir(®) HFA delivers warmer, lower-impact, longer-duration plumes containing higher fine particle dose than Ventolin(®) HFA

BACKGROUND

Inhaler technique and spray characteristics are critical for adequate management of asthma symptoms with pressurized metered-dose inhalers (pMDIs). A lower spray force has been directly associated with a decrease in throat deposition of asthma medication, and a higher spray temperature may alleviate the "cold Freon effect" associated with pMDIs. The objective of the study was to characterize and compare the temperature, maximum spray force, and duration of the emitted plume from two pMDIs: ProAir(®) hydrofluoroalkane (HFA) and Ventolin(®) HFA.

METHODS

A spray force tester model SFT1000 and thermocouple were used to test 10 units from three separate lots (total of 30 units) of each inhaler type. Three consecutive actuations were tested at a spray distance of 40 mm from the edge of the mouthpiece. Room temperature, humidity, and initial weight of the pMDI were recorded. Final weight of each pMDI was recorded to determine the spray weight of individual actuations. pMDIs were primed and operated according to instructions provided in the package insert. Aerodynamic particle size distribution (APSD) was also assessed using a next-generation impactor at a flow rate of 28.3 L/min.

RESULTS

Measurements were obtained from three consecutive actuations for each of 30 units of ProAir(®) HFA and Ventolin(®) HFA (10 units from three separate lots), resulting in a total of 90 actuations tested for each pMDI. Minimum plume temperatures recorded were 7.2 ± 0.7°C and -35.9 ± 12.7°C, respectively, for ProAir(®) HFA and Ventolin(®) HFA. ProAir(®) HFA produced more than a twofold greater plume duration (385 ± 46 ms vs. 156 ± 58 ms; p<0.001) and a significantly lower mean maximum spray force (33.6 ± 11.4 mN vs. 75.9 ± 12.0 mN; p<0.0001) compared with Ventolin(®) HFA. APSD analysis demonstrated that ProAir(®) HFA produced almost twice as much fine particle (<5 μm) dose with lower geometric standard deviation, compared with Ventolin(®) HFA. Two inhalers produced similar mass median aerodynamic diameters, ranging from 2.3 to 2.4 μm.

CONCLUSIONS

The ProAir(®) HFA delivers a warmer, lower-impact, and longer-lasting plume compared with Ventolin(®) HFA, which may provide a more consistent, comfortable experience for patients using a pMDI. ProAir(®) HFA produces higher fine particle dose than Ventolin(®) HFA.

Solvation in hydrofluoroalkanes: how can ethanol help?

Objectives

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

Methods

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

Key findings

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

Conclusions

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

Similar Results in Children with Asthma for Steady State Pharmacokinetic Parameters of Ciclesonide Inhaled with or without Spacer

Background:

Ciclesonide is an inhaled corticosteroid administered by a metered dose inhaler (MDI) to treat bronchial asthma. After inhalation, the inactive ciclesonide is converted by esterases in the airways to active metabolite desisobutyryl-ciclesonide (des-CIC).

Aim:

To compare the pharmacokinetic (PK) parameters of des-CIC in children after administration of therapeutic dose of ciclesonide with and without spacer (AeroChamber Plus^™).

Methods:

Open-label, 3 period, cross over, repeated dose, PK study in 37 children with mild to moderate stable asthma (age: 6–11 y; body weight: 20–53 kg). During each 7-day treatment period, ciclesonide was inhaled once in the morning: A) 160 μg MDI with spacer, B) 80 μg MDI with spacer, and C) 160 μg MDI without spacer. Serum PK parameters of ciclesonide and des-CIC were determined on Day 7 of each period. The primary PK parameters were the AUC_τ and C_max for des-CIC.

Results:

Inhaling ciclesonide with spacer led to a dose proportional systemic exposure (AUC_τ) of des-CIC (0.316 μg*h/L for 80 μg and 0.663 μg*h/L for 160 μg). The dose-normalized systemic exposure for des-CIC (based on AUC_τ) was 27% higher after inhalation of ciclesonide 80 μg or 160 μg with spacer than without spacer; the corresponding C_max values for des-CIC were, respectively, 63% and 55% higher with spacer. No clinically relevant abnormalities or adverse drug reactions were observed.

Conclusions:

Inhalation of therapeutic ciclesonide dose with spacer led to a slight increase in the systemic exposure of des-CIC, which does not warrant dose adjustment.

Inhalable large porous microspheres of low molecular weight heparin: in vitro and in vivo evaluation

This study tests the feasibility of large porous particles as long-acting carriers for pulmonary delivery of low molecular weight heparin (LMWH). Microspheres were prepared with a biodegradable polymer, poly(lactic-co-glycolic acid) (PLGA), by a double-emulsion-solvent-evaporation technique. The drug entrapment efficiencies of the microspheres were increased by modifying them with three different additivespolyethyleneimine (PEI), Span 60 and stearylamine. The resulting microspheres were evaluated for morphology, size, zeta potential, density, in vitro drug-release properties, cytotoxicity, and for pulmonary absorption in vivo. Scanning electron microscopic examination suggests that the porosity of the particles increased with the increase in aqueous volume fraction. The amount of aqueous volume fraction and the type of core-modifying agent added to the aqueous interior had varying degrees of effect on the size, density and aerodynamic diameter of the particles. When PEI was incorporated in the internal aqueous phase, the entrapment efficiency was increased from 16.22+/-1.32% to 54.82+/-2.79%. The amount of drug released in the initial burst phase and the release-rate constant for the core-modified microspheres were greater than those for the plain microspheres. After pulmonary administration, the half-life of the drug from the PEI- and stearylamine-modified microspheres was increased by 5- to 6-fold compared to the drug entrapped in plain microspheres. The viability of Calu-3 cells was not adversely affected when incubated with the microspheres. Overall, the data presented here suggest that the newly developed porous microspheres of LMWH have the potential to be used in a form deliverable by dry-powder inhaler as an alternative to multiple parenteral administrations of LMWH.

Biocompatible and biodegradable copolymer stabilizers for hydrofluoroalkane dispersions: a colloidal probe microscopy investigation

In this work we investigate the ability of biodegradable and biocompatible lactide-based nonionic amphiphiles to stabilize a model drug (salbutamol base) dispersion in hydrofluoroalkane (HFA) propellant. A series of triblock copolymers of the type poly(lactide)-poly(ethylene glycol)-poly(lactide) (LA(m)EO(n)LA(m)) with varying molecular weight (MW) and % EO were synthesized. The cohesive forces between drug particles in liquid HFA in the presence of the amphiphiles were quantitatively determined by colloidal probe microscopy (CPM). The effect of cosolvent, oleic acid, and a nonionic triblock copolymer with the propylene oxide moiety as the HFA-phile was also investigated. CPM results show that the overall concentration, MW, surfactant tail (LA) length, and the ratio between the stabilizing LA moiety and the anchor EO group have a great impact on the drug cohesive forces. The CPM results in liquid HFA were correlated to the bulk physical stability of the drug suspensions in the propellant 1,1,1,2,3,3,3-heptafluoropropane (HFA227). The dispersions in HFA227 were significantly improved in the presence of LA(m)EO(n)LA(m), correlating well with the low cohesive forces determined by CPM. The applicability of LA-based amphiphiles might be extended to other suspension-based formulations provided a suitable headgroup is found. This study is relevant for the development of HFA-based dispersion pressurized metered-dose inhaler formulations.