Pharmacokinetics and systemic activity of fluticasone via Diskus and pMDI, and of budesonide via Turbuhaler

iBCS: 3. A Biopharmaceutics Classification System for Orally Inhaled Drug Products

In this article, we specify for the first time a quantitative biopharmaceutics classification system for orally inhaled drugs. To date, orally inhaled drug product developers have lacked a biopharmaceutics classification system like the one developed to navigate the development of immediate release of oral medicines. Guideposts for respiratory drug discovery chemists and inhalation product formulators have been elusive and difficult to identify due to the complexity of pulmonary physiology, the intricacies of drug deposition and disposition in the lungs, and the influence of the inhalation delivery device used to deliver the drug as a respirable aerosol. The development of an inhalation biopharmaceutics classification system (iBCS) was an initiative supported by the Product Quality Research Institute (PQRI). The goal of the PQRI iBCS working group was to generate a qualitative biopharmaceutics classification system that can be utilized by inhalation scientists as a "rule of thumb" to identify desirable molecular properties and recognize and manage CMC product development risks based on physicochemical properties of the drug and the deposited lung dose. Herein, we define the iBCS classes quantitatively according to the dose number and permeability. The proposed iBCS was evaluated for its ability to categorize marketed inhaled drugs using data from the literature. The appropriateness of the classification of each drug was assessed based on published development, clinical and nonclinical data, and mechanistic physiologically based biopharmaceutics modeling. The inhaled drug product development challenges for each iBCS classification are discussed and illustrated for different classes of marketed inhaled drugs. Finally, it is recognized that discriminatory laboratory methods to characterize regional lung deposition, dissolution, and permeability will be key to fully realizing the benefits of an iBCS to streamline and derisk inhaled drug development.

Inhaled corticosteroid for patients with COVID-19: A systematic review and meta-analysis of randomized controlled trials

BACKGROUND

The efficacy of inhaled corticosteroid (ICS) in the treatment of patients with COVID-19 has been evaluated in randomized controlled trials (RCTs), however, their findings are not consistent.

METHODS

PubMed, Embase, Cochrane Library, ClinicalTrials.gov, Scopus, Web of Science and Google Scholar were searched to June 10, 2023. Only RCTs that investigated the clinical efficacy and safety of ICS for patients with COVID-19 were included.

RESULTS

Eleven RCTs were included. ICS users had significantly higher rate of symptom alleviation at day 14 than the control group (risk ratio [RR], 1.13; 95% CI, 1.04-1.23; I2 = 42%). Additionally, no significant difference between the ICS users and the control group was observed in the composite outcome of urgent care, emergency department (ED) visit or hospitalization (RR, 0.43; 95% CI, 0.08-2.48; I2 = 85%) and hospitalization or death (RR, 0.85; 95% CI, 0.64-1.12; I2 = 0%). Finally, ICS user had a non-significantly lower risk of death at day 28 than the control group (0.63% vs 0.99%; RR, 0.82; 95% CI, 0.43-1.56; I2 = 0%).

CONCLUSIONS

Additional ICS use, particularly inhaled budesonide may help symptom relief in patients with COVID-19. However, ICS use did not help reduce the risk of urgent care, ED visit, hospitalization, or death.

Aerosol technology to mimic dry powder inhalation in vitro using pulmonary cell models

Inhaled therapy confers key advantages for the treatment of topical pulmonary diseases and offers potential for systemic delivery of medicines. Dry powder inhalers (DPIs) are generally the preferred devices for pulmonary delivery due to improved stability and satisfactory patient compliance. However, the mechanisms governing drug powder dissolution and availability in the lung and poorly understood. Here, we report a new in vitro system to study epithelial absorption of inhaled dry powders in lung barrier models of the upper and lower airway. The system is based on a CULTEX® RFS (Radial Flow System) cell exposure module joined to a Vilnius aerosol generator and allows the coupling of drug dissolution and permeability assessments. The cellular models recapitulate the barrier morphology and function of healthy and diseased pulmonary epithelium and incorporate the mucosal barrier to enable the investigation of drug powder dissolution in biorelevant conditions. With this system, we found differences in permeability across the airway tree and pinpointed the impact of diseased barriers in paracellular drug transport. Furthermore, we identified a different rank order of permeability for compounds tested in solution or powder form. These results highlight the value of this in vitro drug aerosolization setup for use in research and development of inhaled medicines.

Central and peripheral lung deposition of fluticasone propionate dry powder inhaler formulations in humans characterized by population pharmacokinetics

This study aimed to gain an in-depth understanding of the pulmonary fate of three experimental fluticasone propionate (FP) dry powder inhaler formulations which differed in mass median aerodynamic diameters (MMAD; A-4.5 µm, B-3.8 µm and C-3.7 µm; total single dose: 500 µg). Systemic disposition parameter estimates were obtained from published pharmacokinetic data after intravenous dosing to improve robustness. A biphasic pulmonary absorption model, with mucociliary clearance from the slower absorption compartment, and three systemic disposition compartments was most suitable. Rapid absorption, presumably from peripheral lung, had half-lives of 6.9 to 14.6 min. The peripherally deposited dose (12.6 µg) was significantly smaller for formulation A-4.5 µm than for the other formulations (38.7 and 39.3 µg for B-3.8 µm and C-3.7 µm). The slow absorption half-lives ranged from 6.86 to 9.13 h and were presumably associated with more central lung regions, where mucociliary clearance removed approximately half of the centrally deposited dose. Simulation-estimation studies showed that a biphasic absorption model could be reliably identified and that parameter estimates were unbiased and reasonably precise. Bioequivalence assessment of population pharmacokinetics derived central and peripheral lung doses suggested that formulation A-4.5 µm lacked bioequivalence compared to the other formulations both for central and peripheral doses. In contrast, the other fomulations were bioequivalent. Overall, population pharmacokinetics holds promise to provide important insights into the pulmonary fate of inhalation drugs, which are not available from non-compartmental analysis. This supports the assessment of the pulmonary bioequivalence of fluticasone propionate inhaled formulations through pharmacokinetic approaches, and may be helpful for discussions on evaluating alternatives to clinical endpoint studies.

A multiplex inhalation platform to model in situ like aerosol delivery in a breathing lung-on-chip

Prolonged exposure to environmental respirable toxicants can lead to the development and worsening of severe respiratory diseases such as asthma, chronic obstructive pulmonary disease (COPD) and fibrosis. The limited number of FDA-approved inhaled drugs for these serious lung conditions has led to a shift from in vivo towards the use of alternative in vitro human-relevant models to better predict the toxicity of inhaled particles in preclinical research. While there are several inhalation exposure models for the upper airways, the fragile and dynamic nature of the alveolar microenvironment has limited the development of reproducible exposure models for the distal lung. Here, we present a mechanistic approach using a new generation of exposure systems, the Cloud α AX12. This novel in vitro inhalation tool consists of a cloud-based exposure chamber (VITROCELL) that integrates the breathing ^AXLung-on-chip system (AlveoliX). The ultrathin and porous membrane of the AX12 plate was used to create a complex multicellular model that enables key physiological culture conditions: the air-liquid interface (ALI) and the three-dimensional cyclic stretch (CS). Human-relevant cellular models were established for a) the distal alveolar-capillary interface using primary cell-derived immortalized alveolar epithelial cells (^AXiAECs), macrophages (THP-1) and endothelial (HLMVEC) cells, and b) the upper-airways using Calu3 cells. Primary human alveolar epithelial cells (^AXhAEpCs) were used to validate the toxicity results obtained from the immortalized cell lines. To mimic in vivo relevant aerosol exposures with the Cloud α AX12, three different models were established using: a) titanium dioxide (TiO2) and zinc oxide nanoparticles b) polyhexamethylene guanidine a toxic chemical and c) an anti-inflammatory inhaled corticosteroid, fluticasone propionate (FL). Our results suggest an important synergistic effect on the air-blood barrier sensitivity, cytotoxicity and inflammation, when air-liquid interface and cyclic stretch culture conditions are combined. To the best of our knowledge, this is the first time that an in vitro inhalation exposure system for the distal lung has been described with a breathing lung-on-chip technology. The Cloud α AX12 model thus represents a state-of-the-art pre-clinical tool to study inhalation toxicity risks, drug safety and efficacy.

In Vitro and In Silico Investigations on Drug Delivery in the Mouth-Throat Models with Handihaler®

This work aimed to evaluate the relative inhalation parameters that affect the deposition of inhaled aerosols, including mouth-throat morphology, airflow rate, and initial condition of emitted particles. In vitro experiments were conducted using the US Pharmacopeia (USP) throat and a realistic mouth-throat (RMT) with Handihaler®. Then, in silico study of the gas-solid flow was performed by computational fluid dynamics and discrete phase method. Results indicated that aerosol deposition in RMT was higher compared to that in USP throat at an airflow rate of 30 L/min, with 33.16 ± 7.84% and 21.11 ± 7.1% lung deposition in USP throat and RMT models, respectively, which showed a better correlation with in vivo data from the literature. Increasing airflow rate resulted in better drug aerosolization, while the fine particle dose trend ascended before declining, with the peak value obtained at a flow rate of 40 L/min. Overall, the effect of geometrical variation was more significant. Additionally, in silico results demonstrated clearly that the initial conditions of the emitted particles from inhalers affected the subsequent deposition. Larger momentum possessed by the central aerosol jet entering the mouth directly led to stronger impaction, which resulted in the deposition in the front region of mouth-throat models. This study is beneficial to develop an in silico method to understand the underlying mechanisms of in vivo mouth-throat deposition.

Characterization of Membrane-Type Dissolution Profiles of Clinically Available Orally Inhaled Products Using a Weibull Fit and a Mechanistic Model

Dissolution rate impacts the absorption rate of poorly soluble inhaled drugs. In vitro dissolution tests that can capture the impact of changes in critical quality attributes of the drug product on in vivo dissolution are important for the development of products containing poorly soluble drugs, as well as modified release formulations. In this study, an extended mathematical model allowing for dissolution of polydisperse powders and subsequent diffusion of dissolved drug across a membrane is described. In vitro dissolution profiles of budesonide, fluticasone propionate, and beclomethasone dipropionate delivered from three commercial drug products were determined using a membrane-type Transwell dissolution test, which consists of a donor and an acceptor compartment separated by a membrane. Subsequently, the profiles were analyzed using the developed mechanistic model and a semi-empirical model based on the Weibull distribution. The two mathematical models provided the same rank order of the performance of the three drug products in terms of dissolution rates, but the rates were significantly different. The faster rate extracted from the mechanistic model is expected to reflect the true dissolution rate of the drug; the Weibull model provides an effective and slower rate that represents not only drug dissolution but also diffusion across the Transwell membrane. In conclusion, the developed extended model provides superior understanding of the dissolution mechanisms in membrane-type (Transwell) dissolution tests.

Budesonide associated with exogenous pulmonary surfactant in a novel formulation to improve the delivery to the lung

Lung delivery for glucocorticoids (GCs) is very low and depends on the system used. Exogenous pulmonary surfactant (EPS) is a promising tool to transporting GCs efficiently to the airways. We developed a new formulation of EPS with Budesonide (BUD) incorporated into EPS membranes (EPS-BUD) to improve lung delivery of BUD. We evaluated the biodistribution and pharmacokinetic of the transported BUD by intra-tracheal instillation of EPS-BUD in healthy rats. Aqueous suspension of Budesonide was used as control. Budesonide and its esters present in trachea, kidneys and lungs were determined by HPLC. The delivery of BUD in lung for EPS-BUD group was 75 % of total instilled and only 35 % for the control group. BUD was rapidly internalized in pneumocytes and a high proportion of Budesonide esters and persistent concentrations of active free BUD were found for up to 6 h after instillation. The new EPS-BUD formulation developed significantly improves the deposition and increases the permanence of BUD in lung.

Drivers of absolute systemic bioavailability after oral pulmonary inhalation in humans

There are few studies in humans dealing with the relationship between physico-chemical properties of drugs and their systemic bioavailability after administration via oral inhalation route (Fpulm). Getting further insight in the determinants of Fpulm after oral pulmonary inhalation could be of value for drugs considered for a systemic delivery as a result of poor oral bioavailability, as well as for drugs considered for a local delivery to anticipate their undesirable systemic effects. To better delineate the parameters influencing the systemic delivery after oral pulmonary inhalation in humans, we studied the influence of physico-chemical and permeability properties obtained in silico on the rate and extent of Fpulm in a series of 77 compounds with or without marketing approval for pulmonary delivery, and intended either for local or for systemic delivery. Principal component analysis (PCA) showed mainly that Fpulm was positively correlated with Papp and negatively correlated with %TPSA, without a significant influence of solubility and ionization fraction, and no apparent link with lipophilicity and drug size parameters. As a result of the small sample set, the performance of the different models as predictive of Fpulm were quite average with random forest algorithm displaying the best performance. As a whole, the different models captured between 50 and 60% of the variability with a prediction error of less than 20%. Tmax data suggested a significant positive influence of lipophilicity on absorption rate while charge apparently had no influence. A significant linear relationship between Cmax and dose (R² = "0.79) highlighted that Cmax was primarily dependent on dose and absorption rate and could be used to estimate Cmax in humans for new inhaled drugs.

In vitro - in vivo - in silico approach in the development of inhaled drug products: Nanocrystal-based formulations with budesonide as a model drug

This study aims to understand the absorption patterns of three different kinds of inhaled formulations via in silico modeling using budesonide (BUD) as a model drug. The formulations investigated in this study are: (i) commercially available micronized BUD mixed with lactose (BUD-PT), (ii) BUD nanocrystal suspension (BUD-NC), (iii) BUD nanocrystals embedded hyaluronic acid microparticles (BUD-NEM). The deposition patterns of the three inhaled formulations in the rats’ lungs were determined in vivo and in silico predicted, which were used as inputs in GastroPlus™ software to predict drug absorption following aerosolization of the tested formulations. BUD pharmacokinetics, estimated based on intravenous data in rats, was used to establish a drug-specific in silico absorption model. The BUD-specific in silico model revealed that drug pulmonary solubility and absorption rate constant were the key factors affecting pulmonary absorption of BUD-NC and BUD-NEM, respectively. In the case of BUD-PT, the in silico model revealed significant gastrointestinal absorption of BUD, which could be overlooked by traditional in vivo experimental observation. This study demonstrated that in vitro-in vivo-in silico approach was able to identify the key factors that influence the absorption of different inhaled formulations, which may facilitate the development of orally inhaled formulations with different drug release/absorption rates.

Combined in Vitro-in Silico Approach to Predict Deposition and Pharmacokinetics of Budesonide Dry Powder Inhalers

PURPOSE

A combined in vitro - in silico methodology was designed to estimate pharmacokinetics of budesonide delivered via dry powder inhaler.

METHODS

Particle size distributions from three budesonide DPIs, measured with a Next Generation Impactor and Alberta Idealized Throat, were input into a lung deposition model to predict regional deposition. Subsequent systemic exposure was estimated using a pharmacokinetic model that incorporated Nernst-Brunner dissolution in the conducting airways to predict the net influence of dissolution, mucociliary clearance, and absorption.

RESULTS

DPIs demonstrated significant in vitro differences in deposition, resulting in large differences in simulated regional deposition in the central conducting airways and the alveolar region. Similar but low deposition in the small conducting airways was observed with each DPI. Pharmacokinetic predictions showed good agreement with in vivo data from the literature. Peak systemic concentration was tied primarily to the alveolar dose, while the area under the curve was more dependent on the total lung dose. Tracheobronchial deposition was poorly correlated with pharmacokinetic data.

CONCLUSIONS

Combination of realistic in vitro experiments, lung deposition modeling, and pharmacokinetic modeling was shown to provide reasonable estimation of in vivo systemic exposure from DPIs. Such combined approaches are useful in the development of orally inhaled drug products.

Risk of active tuberculosis among COPD patients treated with fixed combinations of long-acting beta2 agonists and inhaled corticosteroids

Objectives

To investigate the incidence of active tuberculosis (TB) among COPD patients using fluticasone/salmeterol or budesonide/formoterol, and to identify any differences between these two groups of patients.

Methods

The study enrolled COPD patients from Taiwan NHIRD who received treatment with fluticasone/salmeterol or budesonide/formoterol for > 90 days between 2004 and 2011. The incidence of active TB was the primary outcome.

Results

Among the intention-to-treat population prior to matching, the incidence rates of active TB were 0.94 and 0.61% in the fluticasone/salmeterol and budesonide/formoterol groups, respectively. After matching, the fluticasone/salmeterol group had significantly higher rates of active TB (adjusted HR, 1.41, 95% CI, 1.17–1.70) compared with the budesonide/formoterol group. The significant difference between these two groups remained after a competing risk analysis (HR, 1.45, 95% CI, 1.21–1.74). Following propensity score matching, the fluticasone/salmeterol group had significantly higher rates of active TB compared with the budesonide/formoterol group (adjusted HR, 1.45, 95% CI, 1.14–1.85). A similar trend was observed after a competing risk analysis (HR, 1.44, 95% CI, 1.19–1.75). A higher risk of active TB was observed in the fluticasone/salmeterol group compared with the budesonide/formoterol group across all subgroups, but some differences did not reach statistical significance.

Conclusion

Fluticasone/salmeterol carried a higher risk of active TB compared with budesonide/formoterol among COPD patients.

Anthropometry-based generation of personalized and population-specific human airway models

Understanding aerosol deposition in the human lung is of great significance in pulmonary toxicology and inhalation pharmacology. Adverse effects of inhaled environmental aerosols and pharmacological efficacy of inhaled therapeutics are dependent on aerosol properties as well as person-specific respiratory tract anatomy and physiology. Anatomical geometry and physiological function of human airways depend on age, gender, weight, fitness, health, and disease status. Tools for the generation of the population- and subject-specific virtual airway anatomical geometry based on anthropometric data and physiological vitals are invaluable in respiratory diagnostics, personalized pulmonary pharmacology, and model-based management of chronic respiratory diseases. Here we present a novel protocol and software framework for the generation of subject-specific airways based on anthropometric measurements of the subject's body, using the anatomical input, and the conventional spirometry, providing the functional (physiological) data. This model can be used for subject-specific simulations of respiration physiology, gas exchange, and aerosol inhalation and deposition.

Benefit:Risk Profile of Budesonide in Obstructive Airways Disease

Airway inflammation is a major contributing factor in both asthma and chronic obstructive pulmonary disease (COPD) and represents an important target for treatment. Inhaled corticosteroids (ICS) as monotherapy or in combination therapy with long-acting β₂-agonists or long-acting muscarinic antagonists are used extensively in the treatment of asthma and COPD. The development of ICS for their anti-inflammatory properties progressed through efforts to increase topical potency and minimise systemic potency and through advances in inhaled delivery technology. Budesonide is a potent, non-halogenated ICS that was developed in the early 1970s and is now one of the most widely used lung medicines worldwide. Inhaled budesonide's physiochemical and pharmacokinetic/pharmacodynamic properties allow it to reach a rapid and high airway efficacy due to its more balanced relationship between water solubility and lipophilicity. When absorbed from the airways and lung tissue, its moderate lipophilicity shortens systemic exposure, and its unique property of intracellular esterification acts like a sustained release mechanism within airway tissues, contributing to its airway selectivity and a low risk of adverse events. There is a large volume of clinical evidence supporting the efficacy and safety of budesonide, both alone and in combination with the fast- and long-acting β₂-agonist formoterol, as maintenance therapy in patients with asthma and with COPD. The combination of budesonide/formoterol can also be used as an as-needed reliever with anti-inflammatory properties, with or without regular maintenance for asthma, a novel approach that is already approved by some country-specific regulatory authorities and currently recommended in the Global Initiative for Asthma (GINA) guidelines. Budesonide remains one of the most well-established and versatile of the inhaled anti-inflammatory drugs. This narrative review provides a clinical reappraisal of the benefit:risk profile of budesonide in the management of asthma and COPD.

Development of an Aerosol Dose Collection Apparatus for In Vitro Dissolution Measurements of Orally Inhaled Drug Products

The aim of the study was to develop a robust and standardized in vitro dissolution methodology for orally inhaled drug products (OIDPs). An aerosol dose collection (ADC) system was designed to uniformly deposit the whole impactor stage mass (ISM) over a large filter area for dissolution testing. All dissolution tests were performed under sink conditions in a sodium phosphate buffered saline solution containing 0.2%w/w sodium dodecyl sulphate. An adapted USP Apparatus V, Paddle over Disk (POD), was used throughout the study. The dissolution characteristics of the ISM dose of a commercial metered-dose inhaler (MDI) and a range of dry powder inhaler (DPI) formulations containing inhaled corticosteroids were tested. The uniform distribution of the validated ISM dose considerably reduced drug loading effects on the dissolution profiles for both MDI and DPI formulations. The improvement in the robustness and discriminatory capability of the technique enabled characterization of dissolution rate differences between inhaler platforms and between different DPI product strengths containing fluticasone propionate. A good correlation between in vivo mean absorption time and in vitro dissolution half-life was found for a range of the inhaled corticosteroids. The ADC system and the reproducible in vitro POD dissolution measurements provided a quantitative-based approach for measuring the relationship between the influence of device and the dispersion characteristics on the aerosol dissolution of low solubility compounds. The in vitro dissolution method could potentially be applied as a dissolution methodology for compendial, quality control release testing, and during development of both branded orally inhaled drug products and their generic counterparts.

Equivalent Systemic Exposure to Fluticasone Propionate/Salmeterol Following Single Inhaled Doses from Advair Diskus and Wixela Inhub: Results of Three Pharmacokinetic Bioequivalence Studies

Background: Wixela® Inhub® was developed to deliver inhaled fluticasone propionate/salmeterol (FP/S) combination as a substitutable generic equivalent to Advair® Diskus®. These studies aimed to confirm the pharmacokinetic bioequivalence (BE) of FP/S after single doses of Wixela Inhub (test [T]) and Advair Diskus (reference [R]). Methods: Three open-label, randomized, two-way crossover, single-dose studies in healthy subjects (N = 66 each) compared the systemic exposure of FP and salmeterol after inhalation from three dose strengths of FP/S (100/50, 250/50, or 500/50 μg) delivered from T and R. Primary BE endpoints were the area under the plasma concentration-time curve from time = 0 to the last measurable concentration (AUC(0-t)) and the maximum observed plasma concentration (Cmax) for both FP and S. The BE acceptance criteria specified that the 90% confidence intervals (CIs) of the geometric mean T/R ratios for AUC(0-t) and Cmax can be contained within 0.80-1.25 for both FP and salmeterol. Results: Wixela Inhub met the acceptance criteria for BE for FP and salmeterol at each dose strength. Estimated AUC(0-t) and Cmax geometric mean ratios (T/R [90% CI]) for FP were, respectively, 1.04 (1.00-1.08) and 0.92 (0.87-0.96) for 100/50 μg FP/S, 1.07 (1.02-1.13) and 1.01 (0.95-1.07) for 250/50 μg, and 0.97 (0.92, 1.00) and 0.90 (0.86-0.93) for 500/50 μg. Estimated AUC(0-t) and Cmax ratios for salmeterol were, respectively, 1.08 (1.04-1.11) and 1.00 (0.94-1.04) for 100/50 μg FP/S, 1.03 (0.99-1.07) and 0.93 (0.87-1.00) for 250/50 μg, and 1.00 (0.96-1.04) and 0.86 (0.81-0.91) for 500/50 μg. FP/S at all doses via both T and R was comparably well tolerated. Conclusions: Wixela Inhub was bioequivalent to Advair Diskus at all three dose strengths for both FP and S, providing direct evidence of equivalent systemic safety and indirect evidence for equivalent pulmonary deposition.

In vitro, ex vivo and in vivo methods of lung absorption for inhaled drugs

The assessment and prediction of lung absorption and disposition are an increasingly essential preclinical task for successful discovery and product development of inhaled drugs for both local and systemic delivery. Hence, in vitro, ex vivo and in vivo preclinical methods of lung absorption continue to evolve with several technical, methodological and analytical refinements. As in vitro lung epithelial cell monolayer models, the air-liquid interface (ALI)-cultured Calu-3 cells have most frequently been used, but the NCI-H441 and hAELVi cells have now been proposed as the first immortalized human alveolar epithelial cells capable of forming highly-restricted monolayers. The primary ALI-cultured three-dimensional (3D) human lung cell barriers have also become available; efforts to incorporate aerosol drug deposition into the in vitro lung cell models continue; and stem cell-derived lung epithelial cells and "lung-on-a-chip" technology are emerging. The ex vivo isolated perfused rat lung (IPRL) methods have increasing been used, as they enable the kinetic determination of tissue/organ-level diffusive and membrane protein-mediated absorption and competing non-absorptive loss; the assessment of "pre-epithelial" aerosol biopharmaceutical events in the lung, such as dissolution and release; and the ex vivo-to-in vivo extrapolation and prediction. Even so, in vivo small rodent-based methods have been of mainstay use, while large animal-based methods find an additional opportunity to study region-dependent lung absorption and disposition. It is also exciting that human pharmacokinetic (PK) profiles and systemic exposures for inhaled drugs/molecules may be able to be predicted from these in vivo rodent PK data following lung delivery using kinetic modeling approach with allometric scaling. Overall, the value of these preclinical assessments appears to have shifted more to their translational capability of predicting local lung and systemic exposure in humans, in addition to rationalizing optimal inhaled dosage form and delivery system for drugs/molecules in question. It is critically important therefore to make appropriate selection and timely exploitation of the best models at each stage of drug discovery and development program for efficient progress toward product approval and clinical use.

Risk of sepsis among patients with COPD treated with fixed combinations of inhaled corticosteroids and long-acting Beta2 agonists

This study aimed to compare the effect of budesonide/formoterol and fluticasone/salmeterol on the risk and outcomes of sepsis in COPD patients. We conducted this study using the Taiwan National Health Insurance Research Database. We included COPD patients prescribed with budesonide/formoterol or fluticasone/salmeterol between 2004 and 2011. Outcomes including sepsis and mortality were measured. 10,267 COPD patients who received fluticasone/salmeterol and 6,844 patients who received budesonide/formoterol were enrolled into this study and then subsequence were adjusted by propensity score weighting. The incidence of sepsis was 5.74 and 4.99 per 100 person-years for the patients receiving fluticasone/salmeterol and budesonide/formoterol, respectively. Fluticasone/salmeterol was associated with higher risk of sepsis (aHR, 1.15; 95%CI, 1.07-1.24) and septic shock (aHR, 1.14; 95%CI, 1.01-1.29) than budesonide/formoterol. Besides, fluticasone/salmeterol was associated with higher risk of death (aHR, 1.090; 95%CI, 1.01-1.18) than budesonide/formoterol. Patients receiving fluticasone/salmeterol had a significant higher risk of sepsis related respiratory organ dysfunction, lower respiratory tract infection, genitourinary tract infection, bacteremia and skin infection. In conclusion, long-term treatment with budesonide/formoterol was associated with lower rates of sepsis and deaths than fluticasone/salmeterol in patients with COPD.

Crystalline adduct of moxifloxacin with trans-cinnamic acid to reduce the aqueous solubility and dissolution rate for improved residence time in the lungs

A crystalline adduct of the anti-tubercular drug, moxifloxacin and trans-cinnamic acid (1:1 molar ratio (MCA_1:1)) was prepared to prolong the residence time of the drug in the lungs by reducing its solubility and dissolution rate. Whether the adduct is a salt or cocrystal has not been unequivocally determined. Equilibrium solubility and intrinsic dissolution rate measurements for the adduct (MCA_1:1) in phosphate buffered saline (PBS, pH 7.4) revealed a significant decrease in the solubility of moxifloxacin (from 17.68 ± 0.85 mg mL^-1 to 6.10 ± 0.05 mg mL^-1) and intrinsic dissolution rate (from 0.47 ± 0.04 mg cm^-2 min^-1 to 0.14 ± 0.03 mg cm^-2 min^-1) compared to the supplied moxifloxacin. The aerosolization behaviour of the adduct from an inhaler device, Aerolizer^®, using a Next Generation Impactor showed a fine particle fraction of 30.4 ± 1.2%. The dissolution behaviour of the fine particle dose of respirable particles collected was assessed in a small volume of stationary mucus fluid using a custom-made dissolution apparatus. The respirable adduct particles showed a lower dissolution (microscopic observation) and permeation compared to the supplied moxifloxacin. The crystalline adduct MCA_1:1 has a lower solubility and dissolution rate than moxifloxacin and could improve the local residence time and therapeutic action of moxifloxacin in the lungs.

Evaluating fluticasone furoate + vilanterol for the treatment of chronic obstructive pulmonary disease (COPD)

INTRODUCTION

Inhaled corticosteroid/long-acting β-2 agonists (ICS/LABA) combination inhalers have been a lifeline for a generation of chronic obstructive pulmonary disease (COPD) and asthma patients. Fluticasone furoate and Vilanterol (FF/VI) as a once-daily ICS/LABA combination have an extensive clinical trial and real-world data to support its use in COPD patients. Areas covered: The authors provide pharmacological profiles of fluticasone furoate, vilanterol and the FF/VI fixed dose combination. Salient clinical trials evaluating efficacy and safety of the FF/VI combination, and studies demonstrating the impact on COPD exacerbation risk and mortality are also discussed. Expert opinion: ICS/LABA combinations provide bronchodilation and decrease the frequency of COPD exacerbations. Individualizing treatment of each COPD patient based on unique phenotypes will maximize chances of therapeutic responsiveness. Asthma-COPD overlap (ACO), patients with sputum and/or blood eosinophilia, patients with a brisk bronchodilator response, and patients with frequent exacerbations are more likely to show a therapeutic response to ICS than populations who have none of these features. FF/VI will likely remain a popular ICS/LBA combination to treat COPD, as a once-daily inhaled therapy delivered via the Ellipta device popular with COPD patients, with extensive clinical trial and real-world data to support its use.

A new hypothesis to investigate bioequivalence of pharmaceutical inhalation products

BACKGROUND

This short communication reports a new hypothesis regarding bioequivalence of inhalation products which can potentially provide a reliable means to compare pharmaceutical aerosol formulations and inhalers.

METHODS

Available methods regarding the bioequivalence studies, inhaled drugs and advantages of exhaled breath condensate (EBC) samples were reviewed to develop this hypothesis.

RESULTS

It is postulated that two inhalation products providing the same drug concentrations in airway lining fluid (ALF) could be considered bioequivalent. The use of EBC tests which reflect ALF composition can be recommended as an alternative to current testing methods for consideration of bioequivalence.

CONCLUSION

The methods based on EBC analysis can potentially be applied to bioequivalence study of inhalation products and could reflect drug concentration in ALF. However, experimental studies would be necessary to support or refute this hypothesis on the novel application of EBC to bioequivalence in the future. Graphical abstract In vitro (cascade impactor) and In vivo (EBC concentration) corrolation for inhaled drugs.

Characterization of a dextran-budesonide prodrug for inhalation therapy

Reducing the dosing frequency of corticosteroids may increase compliance and increase pulmonary targeting. The objective of this study was to evaluate whether a high molecular weight dextran-budesonide conjugate might be suitable for pulmonary slow release of the otherwise fast absorbed budesonide. An array of dextran-spacer-budesonide conjugates was prepared that differed in the molecular weight of dextran (20 kDa or 40 kDa) and the length of the dicarboxylic spacer (succinic, glutaric, and adipic anhydride). The conjugates were characterized for identity by proton nuclear magnetic resonance (¹H NMR) and Fourier-transform infrared spectroscopy (FTIR), the degree of dextran-hydroxyl conjugation, purity, and physiological activation (release of budesonide). The 40 kDa dextran-succinate-budesonide conjugate was formulated as a dry powder for pulmonary delivery and characterized for particle size distribution, particle morphology, and aerodynamic particle size. The degree of substitution (grams of budesonide in 100 g of conjugate) ranged from 4 to 10% for all six dextran-spacer-budesonide conjugates. Incubation at 37 °C and pH 7.4 in phosphate buffered saline resulted in release of 25-75% of the conjugated budesonide over an 8-hour period with the rate of release increasing with molecular weight of dextran and the length of the spacer. Modeling of the concentration time profiles of the released budesonide and budesonide-21-hemisucinate in phosphate buffered saline, suggested that budesonide is generated either directly or via the budesonide-21-hemisucinate pre-cursor. Data also suggested that the rate of budesonide generation likely depends on the position of budesonide on the dextran molecule. Spray-drying the 40 kDa dextran-succinate-budesonide produced respirable particles of the conjugate with a mass median aerodynamic particle size (MMAD) of 4 μm. The slow generation of budesonide from the chemical delivery system might further improve the pharmacological profile of budesonide.

A compartment-quasi-3D multiscale approach for drug absorption, transport, and retention in the human lungs

Most current models used for modeling the pulmonary drug absorption, transport, and retention are 0D compartmental models where the airways are generally split into the airways and alveolar sections. Such block models deliver low fidelity solutions and the spatial lung drug concentrations cannot be obtained. Other approaches use high fidelity CFD models with limited capabilities due to their exorbitant computational cost. Recently, we presented a novel, fast-running and robust quasi-3D (Q3D) model for modeling the pulmonary airflow. This Q3D method preserved the 3D lung geometry, delivered extremely accurate solutions, and was 25 000 times faster in comparison to the CFD methods. In this paper, we present a Q3D-compartment multiscale combination to model the pulmonary drug absorption, transport, and retention. The initial deposition is obtained from CFD simulations. The lung absorption compartment model of Yu and Rosania is adapted to this multiscale format. The lung is modeled in the Q3D format till the eighth airway generation. The remainder of the lung along with the systemic circulation and elimination processes was modeled using compartments. The Q3D model is further adapted, by allowing for various heterogeneous annular lung layers. This allows us to model the drug transport across the layers and along the lung. Using this multiscale model, the spatiotemporal drug concentrations in the different lung layers and the temporal concentration in the plasma are obtained. The concentration profile in the plasma was found to be better aligned with the experimental findings in comparison with compartmental model for the standard test cases. Thus, this multiscale model can be used to optimize the target-specific drug delivery and increase the localized bioavailability, thereby facilitating applications from the bench to bedside for various patient/lung-disease variations.

On the pharmacokinetics of two inhaled budesonide/formoterol combinations in asthma patients using modeling approaches

Dry powder inhalers containing the budesonide/formoterol combination have currently a well-established position among other inhaled products. Even though their efficacy mainly depends on the local concentrations of the drug they deliver within the lungs, their safety profile is directly related to their total systemic exposure. The aim of the present investigation was to explore the absorption and disposition kinetics of the budesonide/formoterol combination delivered via two different dry powder inhalers in asthma patients. Plasma concentration-time data were obtained from a single-dose, crossover bioequivalence study in asthma patients. Non-compartmental and population compartmental approaches were applied to the available datasets. The non-compartmental analysis allowed for an initial characterization of the primary pharmacokinetic (PK) parameters of the two inhaled drugs and subsequently the bioequivalence assessment of the two different dry powder inhalers. The population pharmacokinetic analysis further explored the complex absorption and disposition characteristics of the two drugs. In case of inhaled FOR, a five-compartment PK model including an enterohepatic re-circulation process was developed. For inhaled BUD, the incorporation of two parallel first-order absorption rate constants (fast and slow) for lung absorption in a two-compartment PK model emphasized the importance of pulmonary anatomical features and underlying physiological processes during model development. The role of potential covariates on the variability of the PK parameters was also investigated.

Scientific rationale for the possible inhaled corticosteroid intraclass difference in the risk of pneumonia in COPD

Inhaled corticosteroids (ICSs) treatment combined with long-acting β2-adrenoceptor agonists (LABAs) reduces the risk of exacerbations in COPD, but the use of ICSs is associated with increased incidence of pneumonia. There are indications that this association is stronger for fluticasone propionate than for budesonide. We have examined systematic reviews assessing the risk of pneumonia associated with fluticasone propionate and budesonide COPD therapy. Compared with placebo or LABAs, we found that fluticasone propionate was associated with 43%-78% increased risk of pneumonia, while only slightly increased risk or no risk was found for budesonide. We have evaluated conceivable mechanisms which may explain this difference and suggest that the higher pneumonia risk with fluticasone propionate treatment is caused by greater and more protracted immunosuppressive effects locally in the airways/lungs. These effects are due to the much slower dissolution of fluticasone propionate particles in airway luminal fluid, resulting in a slower uptake into the airway tissue and a much longer presence of fluticasone propionate in airway epithelial lining fluid.

Severe exacerbation and pneumonia in COPD patients treated with fixed combinations of inhaled corticosteroid and long-acting beta2 agonist

BACKGROUND

It remains unclear whether severe exacerbation and pneumonia of COPD differs between patients treated with budesonide/formoterol and those treated with fluticasone/salmeterol. Therefore, we conducted a comparative study of those who used budesonide/formoterol and those treated with fluticasone/salmeterol for COPD.

METHODS

Subjects in this population-based cohort study comprised patients with COPD who were treated with a fixed combination of budesonide/formoterol or fluticasone/salmeterol. All patients were recruited from the Taiwan National Health Insurance database. The outcomes including severe exacerbations, pneumonia, and pneumonia requiring mechanical ventilation (MV) were measured.

RESULTS

During the study period, 11,519 COPD patients receiving fluticasone/salmeterol and 7,437 patients receiving budesonide/formoterol were enrolled in the study. Pairwise matching (1:1) of fluticasone/salmeterol and budesonide/formoterol populations resulted in to two similar subgroups comprising each 7,295 patients. Patients receiving fluticasone/salmeterol had higher annual rate and higher risk of severe exacerbation than patients receiving budesonide/formoterol (1.2219/year vs 1.1237/year, adjusted rate ratio, 1.08; 95% CI, 1.07-1.10). In addition, patients receiving fluticasone/salmeterol had higher incidence rate and higher risk of pneumonia than patients receiving budesonide/formoterol (12.11 per 100 person-years vs 10.65 per 100 person-years, adjusted hazard ratio [aHR], 1.13; 95% CI, 1.08-1.20). Finally, patients receiving fluticasone/salmeterol had higher incidence rate and higher risk of pneumonia requiring MV than patients receiving budesonide/formoterol (3.94 per 100 person-years vs 3.47 per 100 person-years, aHR, 1.14; 95% CI, 1.05-1.24). A similar trend was seen before and after propensity score matching analysis, intention-to-treat, and as-treated analysis with and without competing risk.

CONCLUSIONS

Based on this retrospective observational study, long-term treatment with fixed combination budesonide/formoterol was associated with fewer severe exacerbations, pneumonia, and pneumonia requiring MV than fluticasone/salmeterol in COPD patients.

Inhaled Corticosteroid use and the Risk of Pneumonia and COPD Exacerbations in the UPLIFT Study

RATIONALE

Unlike many other COPD studies, the 4-year UPLIFT trial permitted inhaled corticosteroid (ICS) use during run-in and treatment phases. This provided the opportunity to prospectively observe the continuing effects of ICS on respiratory events in closely observed COPD population.

OBJECTIVES

We aimed to determine rate and number of episodes of pneumonia and exacerbations of COPD in patients entering the study on no ICS, fluticasone proprionate (FP), and other ICS.

METHODS

The UPLIFT dataset was examined retrospectively, and patients were divided into three groups based on their medications at entry: no ICS, FP and other ICS. Poisson regression was used to compare the frequency of respiratory adverse events.

MEASUREMENTS AND MAIN RESULTS

At entry, the groups were well matched apart from a higher FEV1% predicted (38 vs. 41%; ICS vs. no ICS, respectively) and prevalence of current smoking (26 vs. 36%; ICS vs. no ICS, respectively). Incidence rates of pneumonia were significantly higher in patients taking ICS compared to no ICS (0.068 vs. 0.056 respectively; p = 0.012). When the FP group was compared to the other ICS, the event rate was even higher (0.077 vs. 0.058, respectively; p < 0.001). COPD exacerbations were more frequent in patients taking ICS, with significantly greater rate in the FP group compared to that seen with other ICS (0.93 vs. 0.84 respectively; p = 0.013).

CONCLUSIONS

ICS use was associated an increase in respiratory adverse event rates, but whether this was due to more severe illness at entry is unknown. In subgroup analysis, the excess of morbidity in the ICS group appeared to be mainly associated with those receiving FP at randomisation.

Between-Batch Pharmacokinetic Variability Inflates Type I Error Rate in Conventional Bioequivalence Trials: A Randomized Advair Diskus Clinical Trial

We previously demonstrated pharmacokinetic differences among manufacturing batches of a US Food and Drug Administration (FDA)-approved dry powder inhalation product (Advair Diskus 100/50) large enough to establish between-batch bio-inequivalence. Here, we provide independent confirmation of pharmacokinetic bio-inequivalence among Advair Diskus 100/50 batches, and quantify residual and between-batch variance component magnitudes. These variance estimates are used to consider the type I error rate of the FDA's current two-way crossover design recommendation. When between-batch pharmacokinetic variability is substantial, the conventional two-way crossover design cannot accomplish the objectives of FDA's statistical bioequivalence test (i.e., cannot accurately estimate the test/reference ratio and associated confidence interval). The two-way crossover, which ignores between-batch pharmacokinetic variability, yields an artificially narrow confidence interval on the product comparison. The unavoidable consequence is type I error rate inflation, to ∼25%, when between-batch pharmacokinetic variability is nonzero. This risk of a false bioequivalence conclusion is substantially higher than asserted by regulators as acceptable consumer risk (5%).

The association between inhaled corticosteroid and pneumonia in COPD patients: the improvement of patients' life quality with COPD in Taiwan (IMPACT) study

To investigate the association between inhaled corticosteroid (ICS) exposure patterns and the risk of pneumonia in chronic obstructive pulmonary disease (COPD) patients, we performed a nested case-control study. Between 1998 and 2010, 51,739 patients, including 19,838 cases of pneumonia, were matched to 74,849 control subjects selected from a cohort of COPD patients using ICSs via risk-set sampling of the database constructed by the National Health Research Institutes of Taiwan. After adjusting for covariates, the current use of ICSs was associated with a 25% increase in the risk of pneumonia (odds ratio [OR] =1.25, 95% confidence interval [CI] =1.20–1.30), and there was an increase in the OR with increase in the average daily dosage. Additionally, users of fluticasone/salmeterol, fluticasone, and either fluticasone/salmeterol or fluticasone were more likely to be at a higher risk of pneumonia (OR =1.35, 95% CI =1.28–1.41; OR =1.22, 95% CI =1.10–1.35; and OR =1.33, 95% CI =1.27–1.39, respectively). In contrast, there were no statistically significant associations between the risk of pneumonia and the use of budesonide/formoterol, budesonide, or either budesonide/formoterol or budesonide. In conclusion, ICSs are significantly associated with an increased risk of pneumonia in COPD patients. The effect is prominent for fluticasone-containing ICSs but not for budesonide-containing ICSs.

Long-Term Fluticasone Propionate/Formoterol Fumarate Combination Therapy Is Associated with a Low Incidence of Severe Asthma Exacerbations

BACKGROUND

A primary goal of asthma management is the reduction of exacerbation risk. We assessed the occurrence of oral corticosteroid-requiring exacerbations (OCS exacerbations) with long-term fluticasone/formoterol therapy, and compared it with the occurrence of similar events reported with other inhaled corticosteroid/long acting β2-agonist (ICS/LABA) combinations.

METHODS

The occurrence of OCS exacerbations was assessed in two open-label trials of fixed-dose fluticasone/formoterol administered for between 26 to 60 weeks in adults and adolescents with asthma. The incidence of OCS exacerbations with fluticasone/formoterol was compared with those reported in three recent Cochrane meta-analyses of other ICS/LABAs.

RESULTS

The pooled incidence of OCS exacerbations with long-term fluticasone/formoterol was 2.1% (95% CI: 1.1, 3.2%, n/N = 16/752). In only two of the nineteen treatment arms summarized by Cochrane did OCS exacerbation incidence approximate that seen in the two fluticasone/formoterol trials (single-inhaler fluticasone/salmeterol [2.9%]; separate inhaler budesonide, beclometasone, or flunisolide plus formoterol [3.4%]). In Lasserson's review the pooled incidence of OCS exacerbations for single-inhaler combinations was 9.5% (95% CI: 8.4, 10.6%; n/N = 239/2516) for fluticasone/salmeterol, and 10.6% (95% CI: 9.3, 11.8%; n/N = 257/2433) for budesonide/formoterol. In Ducharme's and Chauhan's meta-analyses (primarily incorporating separate inhaler combinations [fluticasone, budesonide, beclometasone, or flunisolide plus salmeterol or formoterol]), the pooled incidences of OCS exacerbations were 16.0% (95% CI: 14.2, 17.8%, n/N = 258/1615) and 16.7% (95% CI: 14.9, 18.5, n/N = 275/1643), respectively.

CONCLUSIONS

The incidence of exacerbations in two fixed-dose fluticasone/formoterol studies was low and less than in the majority of comparable published studies involving other ICS/LABA combinations. This difference could not be readily explained by differences in features of the respective studies and may be related to the favorable pharmacological/mechanistic characteristics of the constituent components fluticasone and formoterol compared to other drugs in their respective classes.

Performance of Turbuhaler((R)) in Patients with Acute Airway Obstruction and COPD, and in Children with Asthma : Understanding the Clinical Importance of Adequate Peak Inspiratory Flow, High Lung Deposition, and Low In Vivo Dose Variability

The dry-powder inhaler (DPI) Turbuhaler((R)) has been on the market for nearly two decades. Products containing terbutaline, formoterol, budesonide, and the combination budesonide/formoterol are widely used by patients with asthma and COPD. Most patients and physicians find Turbuhaler((R)) easy to use, and local side effects are rare. This is thought to arise from the lack of additives or only small amounts in the formulation, in addition to minimal deposition of the drug in the oropharynx and on the vocal cords during inspiration.The function of Turbuhaler((R)) has frequently been questioned. This article aims to review and clarify some key issues that have been challenged in the literature (e.g. the effectiveness of Turbuhaler((R)) in patients with more restricting conditions), to discuss the importance of lung deposition, and to explain the low in vivo variability associated with Turbuhaler((R)) and the lack of correlation with the higher in vitro variability.Turbuhaler((R)), like other DPIs, is flow dependent to some degree. However, a peak inspiratory flow (PIF) through Turbuhaler((R)) of 30 L/min gives a good clinical effect. These PIF values can be obtained by patients with conditions thought to be difficult to manage with inhalational agents, such as asthmatic children and adult patients with acute severe airway obstruction and COPD. Excellent clinical results with Turbuhaler((R)) in large controlled studies in patients with COPD and acute severe airway obstruction provide indirect evidence that medication delivered via Turbuhaler((R)) reaches the target organ.Due to the large amount of small particles and the moderate inbuilt resistance in Turbuhaler((R)), which opens up the vocal cords during inhalation, Turbuhaler((R)) is associated with a high lung deposition (25-40% of the delivered dose) compared with pressurized metered-dose inhalers (pMDIs) and other DPIs. A good correlation has been found between lung deposition and clinical efficacy. A high lung deposition always results in the best ratio between clinical efficacy and risk of unwanted systemic activity. Studies with Turbuhaler((R)) also show that the in vivo variation in lung deposition is significantly lower compared with a pMDI or, for example, the Diskus((R)) inhaler, and much lower than the in vitro dose variability seen in laboratory tests. Turbuhaler((R)) appears to be a reliable DPI which can be used with confidence by patients with airway diseases, including those with clinical conditions believed to be difficult to manage with inhalational therapy.

Effects of low- versus high-dose fluticasone propionate/formoterol fumarate combination therapy on AMP challenge in asthmatic patients: A double-blind, randomised clinical trial

BACKGROUND

The dose-response relationship between two dose levels of fluticasone/formoterol (flutiform(®), 100/10 μg and 500/20 μg) was evaluated in asthmatic patients. Non-invasive inflammatory markers were used including adenosine monophosphate (AMP) challenge (primary endpoint), and sputum eosinophils and fractional exhaled nitric oxide (FeNO) (secondary endpoints).

METHODS

Patients aged ≥18 years with forced expiratory volume in 1 s (FEV1) ≥60% predicted and who required a dose of <60 mg AMP to elicit a 20% drop in FEV1 (AMP PD20) were randomised in this incomplete block, crossover study to receive 2 of 3 treatments b.i.d.: fluticasone/formoterol 500/20 μg (high dose), 100/10 μg (low dose) or placebo, during 2 periods of 28 ± 3 days each, separated by 2-3 weeks. AMP challenges were performed pre-dose and 12 h after last dose at the end of each treatment period. A series of post hoc analyses were performed only in patients allocated to both fluticasone/formoterol doses, who completed the study and had evaluable AMP PD20 data for both treatments ("fluticasone/formoterol subgroup"). Changes in AMP PD20 FEV1, percentage sputum eosinophils and FeNO levels (Day 1 vs Day 28) between treatments were compared by an analysis of covariance (ANCOVA).

RESULTS

Sixty-two patients were randomised and 46 completed the study. Fifteen patients received both high- and low-dose fluticasone/formoterol (post hoc subgroup). The difference in AMP PD20 for the overall population was not statistically significant between high- and low-dose fluticasone/formoterol (LS mean fold difference: 1.3; p = 0.489), although both dose levels were superior to placebo: high-dose vs placebo LS mean fold difference: 4.4, p < 0.001; low-dose vs placebo LS mean fold difference: 3.5, p < 0.001. In the post hoc subgroup, the difference in AMP PD20 between the doses was statistically significant in favour of the high-dose (LS mean fold difference: 2.4, p = 0.012). Other inflammatory parameters (sputum eosinophil counts and FeNO) showed small differences and statistically non-significant changes between high- and low-dose fluticasone/formoterol.

CONCLUSIONS

A significant dose-response was found between low- and high-dose fluticasone/formoterol in the post hoc subgroup (patients who received both doses), but not in the overall population, with the higher dose demonstrating a greater reduction in airway responsiveness to AMP.

Pharmacokinetics, Safety, and Tolerability of a New Fluticasone Propionate Multidose Dry Powder Inhaler Compared With Fluticasone Propionate Diskus(®) in Healthy Adults

BACKGROUND

Fluticasone propionate (Fp) is an inhaled corticosteroid with well-established safety and efficacy profiles. This study evaluated the systemic pharmacokinetics of Fp inhaled from a novel, inhalation-driven multidose dry powder inhaler (MDPI) that does not require coordination of actuation with inhalation.

METHODS

This was a single-center, open-label, randomized, 3-period crossover, single-dose study in healthy Japanese and Caucasian subjects aged 20-45 years, inclusive. Subjects were randomized to one of six treatment sequences including combinations of four inhalations of Fp MDPI 100 μg (400 μg total dose), Fp MDPI 200 μg (800 μg total dose), and Fp Diskus(®) 100 μg (400 μg total dose). The primary objective was to assess pharmacokinetics (maximum plasma concentration [Cmax] and area under concentration-vs.-time curve [AUC]) for each treatment. Safety and tolerability were also assessed.

RESULTS

Thirty subjects (15 Caucasian, 15 Japanese) met entry criteria and were randomized; all 30 subjects completed the study. At the inhaled Fp total doses evaluated (400 and 800 μg), the shapes of plasma concentration-vs.-time curves and systemic exposure (AUC0-t and Cmax) were similar in Japanese and Caucasian subjects. Geometric mean ratios (Japanese/Caucasian) for AUC0-t ranged from 1.11 to 1.15, and for Cmax ranged from 0.90 to 1.05, with no substantial differences between ethnic groups. In both ethnic groups, and in the combined population, systemic exposure (AUC0-t and Cmax) was highest for Fp MDPI 800 μg, followed by Fp MDPI 400 μg, and last by Fp Diskus 400 μg. No clinical laboratory, vital signs, or physical examination findings were considered clinically significant.

CONCLUSIONS

Systemic exposure following inhaled single doses of Fp was comparable in healthy adult Japanese and Caucasian subjects for each total dose and inhaler. The new MDPI provided more efficient drug delivery than Diskus, suggesting that Fp MDPI may provide similar clinical efficacy at a lower inhaled dose compared with Diskus. Single-dose inhaled Fp (400-800 μg) was generally well tolerated in healthy adults.

Self-reported osteoporosis prevention in inhaled corticosteroid users in community pharmacy setting

OBJECTIVES

The use of inhaled corticosteroids is the standard maintenance therapy in asthma therapy and as adjunct therapy in moderate to severe chronic obstructive pulmonary disease. A dose-related increase in fracture risk is associated with inhaled corticosteroid use; there is an inverse relationship between bone mineral density and duration and cumulative dose of inhaled corticosteroid. Adequate intake of calcium and vitamin D are cornerstones of osteoporosis prevention. The objectives are to assess whether the proportion of patients receiving inhaled corticosteroids are taking calcium and vitamin D; the association between long-term inhaled corticosteroid use and abnormal bone mineral density or fractures; and how many qualified patients received bone mineral density scans.

METHODS

Patients who filled a prescription for inhaled corticosteroids at selected community pharmacies across Alberta were recruited for a survey of their osteoporosis prevention activities.

RESULTS

A total of 256 patients from 12 community pharmacies were included. The average age was 60 ± 17.4 years with 65% female. There were 21%, 51%, and 28% of patients on high, medium, and low dose inhaled corticosteroids, respectively. Only 17% of patients >50 years old received recommended calcium and vitamin D supplementation and 87 (73%) of the qualified patients received bone mineral density scan.

CONCLUSION

Osteoporosis prevention in inhaled corticosteroid users is currently poorly addressed. More promotion is needed to raise pharmacist awareness of the risks of inhaled corticosteroids.

In Vitro Testing for Orally Inhaled Products: Developments in Science-Based Regulatory Approaches

This article is part of a series of reports from the "Orlando Inhalation Conference-Approaches in International Regulation" which was held in March 2014, and coorganized by the University of Florida and the International Pharmaceutical Aerosol Consortium on Regulation and Science (IPAC-RS). The goal of the conference was to foster the exchange of ideas and knowledge across the global scientific and regulatory community in order to identify and help move towards strategies for internationally harmonized, science-based regulatory approaches for the development and marketing approval of inhalation medicines, including innovator and second entry products. This article provides an integrated perspective of case studies and discussion related to in vitro testing of orally inhaled products, including in vitro-in vivo correlations and requirements for in vitro data and statistical analysis that support quality or bioequivalence for regulatory applications.

Incident pneumonia and mortality in patients with chronic obstructive pulmonary disease. A double effect of inhaled corticosteroids?

Inhaled corticosteroids are commonly prescribed for patients with severe chronic obstructive pulmonary disease. Although their use improves quality of life and reduces exacerbations, it is associated with increased risk of pneumonia. Curiously, their use has not been associated with increased risk of pneumonia-related or overall mortality. We review pertinent literature to further explore the effects of inhaled corticosteroids on incident pneumonia and mortality in patients with chronic obstructive pulmonary disease. The association of use of inhaled corticosteroids and incident pneumonia is substantial and has been present in the majority of the studies on the topic. This includes both randomized controlled trials and observational studies. However, all of the studies have substantial risk of bias. Most randomized trials are limited by lack of systematic ascertainment of pneumonia; they depended on adverse event reporting. Many observational studies included proper radiographic assessment of pneumonia, but they are limited by their retrospective, observational design. The unadjusted higher risk of pneumonia is associated with longer duration of use, more potent ICS compounds, and higher doses. That implies a dose-effect relationship. Unlike pneumonia, mortality is a precise outcome. Despite the robust association of inhaled corticosteroid use with increased risk of pneumonia, all studies find either no difference or a reduction in pulmonary-related and overall mortality associated with the use of inhaled corticosteroids. These observations suggest a double effect of inhaled corticosteroids (i.e., an adverse effect plus an unexplained mitigating effect).

Which factors affect the choice of the inhaler in chronic obstructive respiratory diseases?

Inhalation is the preferred route of drug administration in chronic respiratory diseases because it optimises delivery of the active compounds to the targeted site and minimises side effects from systemic distribution. The choice of a device should be made after careful evaluation of the patient's clinical condition (degree of airway obstruction, comorbidities), as well as their ability to coordinate the inhalation manoeuvre and to generate sufficient inspiratory flow. These patient factors must be aligned with the specific advantages and limitations of each inhaler when making this important choice. Finally, adherence to treatment is not the responsibility of the patient alone, but should be shared also by clinicians. Clinicians have access to a wide selection of pressurised metered dose inhalers (pMDIs) and dry powder inhalers (DPIs) that can be used effectively when matched to the needs of individual patients; this should be perceived as an opportunity rather than a limitation.

Integration of active pharmaceutical ingredient solid form selection and particle engineering into drug product design

This review seeks to offer a broad perspective that encompasses an understanding of the drug product attributes affected by active pharmaceutical ingredient (API) physical properties, their link to solid form selection and the role of particle engineering. While the crucial role of active pharmaceutical ingredient (API) solid form selection is universally acknowledged in the pharmaceutical industry, the value of increasing effort to understanding the link between solid form, API physical properties and drug product formulation and manufacture is now also being recognised.

A truly holistic strategy for drug product development should focus on connecting solid form selection, particle engineering and formulation design to both exploit opportunities to access simpler manufacturing operations and prevent failures. Modelling and predictive tools that assist in establishing these links early in product development are discussed. In addition, the potential for differences between the ingoing API physical properties and those in the final product caused by drug product processing is considered. The focus of this review is on oral solid dosage forms and dry powder inhaler products for lung delivery.

Delivery strategies for sustained drug release in the lungs

Drug delivery to the lungs by inhalation offers a targeted drug therapy for respiratory diseases. However, the therapeutic efficacy of inhaled drugs is limited by their rapid clearance in the lungs. Carriers providing sustained drug release in the lungs can improve therapeutic outcomes of inhaled medicines because they can retain the drug load within the lungs and progressively release the drug locally at therapeutic levels. This review presents the different formulation strategies developed to control drug release in the lungs including microparticles and the wide array of nanomedicines. Large and porous microparticles offer excellent aerodynamic properties. Their large geometric size reduces their uptake by alveolar macrophages, making them a suitable carrier for sustained drug release in the lungs. Similarly, nanocarriers present significant potential for prolonged drug release in the lungs because they largely escape uptake by lung-surface macrophages and can remain in the pulmonary tissue for weeks. They can be embedded in large and porous microparticles in order to facilitate their delivery to the lungs. Conjugation of drugs to polymers as polyethylene glycol can be particularly beneficial to sustain the release of proteins in the lungs as it allows high protein loading. Drug conjugates can be readily delivered to respiratory airways by any current nebulizer device. Nonetheless, liposomes represent the formulation most advanced in clinical development. Liposomes can be prepared with lipids endogenous to the lungs and are particularly safe. Their composition can be adjusted to modulate drug release and they can encapsulate both hydrophilic and lipophilic compounds with high drug loading.