Pharmacokinetic and pharmacodynamic comparison of hydrofluoroalkane and chlorofluorocarbon formulations of budesonide

Association of Nonmedical Switches in Inhaled Respiratory Medications with Disruptions in Care: A Retrospective Prescription Claims Database Analysis

Introduction

There are limited data on the effects of forced medication switching for a nonmedical reason in patients with obstructive airway conditions. This study evaluated disruption in care resulting from a nonmedical medication switch for patients with asthma and/or chronic obstructive pulmonary disease who previously received the inhaled corticosteroid/long-acting β₂-agonist budesonide/formoterol.

Methods

This retrospective pharmacy benefit prescription claims analysis evaluated Medicare Part D patients who filled a prescription for budesonide/formoterol as their last inhaled corticosteroid/long-acting β₂-agonist in 2016 and were affected by a formulary block of budesonide/formoterol in 2017. Changes to respiratory maintenance therapy, length of gaps in care during which a patient was not in possession of a respiratory controller medication, acute medication use indicative of disease exacerbations, and medication adherence were assessed.

Results

A total of 42,553 patients were included in the analysis. Following the formulary block, 30,016 patients (71%) switched to another controller; 20,628 of these patients (69%) switched to a new inhaled corticosteroid/long-acting β₂-agonist, 7081 (23%) stepped down to a monotherapy, and 2307 (8%) switched to a non-inhaled corticosteroid-containing controller. Despite the formulary block, 22,903 patients (54%) attempted to fill budesonide/formoterol as their first postblock controller, and 6624 patients (16%) attempted to return to budesonide/formoterol after switching to another controller. On average, patients experienced a gap in care of approximately 4 months without a controller medication. Also, 9674 (23%) did not fill any controller over the 1-year postblock period. Of those patients who experienced a gap in care, 14,926 (47%) filled a prescription indicative of a possible exacerbation during the gap period (i.e., oral corticosteroids for patients with asthma and oral corticosteroids and/or antibiotics for patients with chronic obstructive pulmonary disease).

Conclusions

The Medicare Part D formulary block was associated with disruption in the management of patients’ respiratory conditions and may have adversely impacted disease control.

Supplementary Information

The online version contains supplementary material available at 10.1007/s41030-021-00147-8.

Inhaled budesonide for the prevention of acute mountain sickness: A meta-analysis of randomized controlled trials

BACKGROUND

Altitude induces acute mountain sickness (AMS), which can affect the health or limit the activities of 15 -80% of climbers and workers. Budesonide has been applied to prevent AMS. However, its prophylactic efficacy is controversial. Our purpose was to conduct a meta-analysis to assess whether budesonide qualifies as a prophylaxis for AMS.

METHODS

A literature search was performed in PubMed, EMBASE, Web of Science, and the Cochrane Library in February 2019. Only randomized controlled trials (RCTs) were selected. The main outcome, AMS, was estimated with the relative risk (RR), weighted mean difference (WMD), and 95% confidence intervals (95% CI). The statistical analysis was performed using Rev. Man 5.3.

RESULTS

Five groups in six articles met the eligibility criteria with 304 participants, including two articles with the same participants but different measurements. Inhaled budesonide showed a potential trend towards preventing AMS, but it was not statistically significant (RR = 0.68, 95% CI: 0.41-1.13, p = 0.14). The subgroup analysis based on dosage (200 µg) did not have significant results. A similar trend was observed for severe AMS and in subgroups stratified by the Lake Louise Score (LLC). However, there was a significant improvement in heart rate (HR) (WMD = -5.41, 95% CI: -8.26 to -2.55, p = 0.0002) and pulse oxygen saturation (SPO2) (WMD = 2.36, 95% CI: 1.62-3.1, p < 0.00001) in the group with inhaled budesonide. Additionally, no side effects were reported in any included study.

CONCLUSION

The current meta-analysis indicates that inhaled budesonide does not protect against AMS or severe AMS. However, it is successful at reducing HR and increasing SPO₂ without any side effects.

Pharmacokinetics and pharmacodynamics of inhaled corticosteroids for asthma treatment

The differences in the pharmacokinetic (PK) characteristics of inhaled corticosteroids (ICSs) critically influence the profile of each of them, but also the significant differences in glucocorticoid receptor selectivity, potency, and physicochemical properties are critical in defining the pharmacodynamic (PD) profile of an ICS. The PK and PD properties of ICSs used in asthma and the importance of their interrelationship have been reviewed. The differences among the ICSs in PK and PD must be considered when an ICS should be prescribed to an asthmatic patient because a better understanding of the PK/PD interrelationship of ICSs could be important to better fit with the between-patient variability and within-patient repeatability in the response to ICSs that often complicate the therapeutic approach to the asthmatic patient. The role of the device in influencing the PK profile of an ICS must be always considered because it is crucial. Also patient-related factors and disease severity affect pulmonary deposition of ICS.

The effects of respiratory inhaled drugs on the prevention of acute mountain sickness

BACKGROUND

Acute mountain sickness (AMS) is common in high-altitude travelers, and may lead to life-threatening high-altitude cerebral edema (HACE) or high-altitude pulmonary edema (HAPE). The inhaled drugs have a much lower peak serum concentrations and a shorter half-life period than oral drugs, which give them a special character, greater local effects in the lung. Meanwhile, short-term administration of inhaled drugs results in almost no adverse reactions.

METHODS

We chose inhaled ipratropium bromide/salbutamol sulfate (combivent, COM), budesonide (pulmicortrespules, BUD), and salbutamol sulfate (ventolin, VEN) in our study to investigate their prophylactic efficacy against AMS. Since COM is a compound drug of ipratropium bromide and salbutamol sulfate, to verify which part of COM plays a role in the prevention of AMS, we also tested VEN in our experiment.

RESULTS

In our study, Lake Louise scores (LLS) in the COM (1.14 ± 0.89 vs 1.91 ± 1.23, P < .05) and BUD (1.35 ± 0.94 vs 1.91 ± 1.23, P < .05) groups were both significantly lower than the placebo group at 72 hours. There were no significant differences in LLS scores among the 4 groups at 120 hours. The incidence of AMS in the COM group was significantly reduced at 72 hours (16.7% in COM group vs 43.4% in placebo group, P < .05) after exposure to high-altitude. There were no significant differences in AMS incidences at 120 hours among the 4 groups.

CONCLUSION

The prophylactic use of COM could prevent AMS in young Chinese male at 72 hours after high-altitude exposure. BUD also could reduce LLS but not prevent AMS at 72 hours. Ipratropium bromide maybe the effective drug in COM work on the prevention of AMS alone.

Scientific Rationale for Determining the Bioequivalence of Inhaled Drugs

In recent years, pathways for the development and approval of bioequivalent inhaled products have been established for regulated markets, including the European Union (EU), and a number of orally inhaled products (OIPs) have been approved in the EU solely on the basis of in vitro and pharmacokinetic data. This review describes how these development pathways are structured and their implications for the treatment of airway diseases such as asthma. The EU guidance follows a stepwise approach that includes in vitro criteria as the first step. If all in vitro criteria are not met, the second step is based on pharmacokinetic evaluations, which include assessments of lung and systemic bioavailability. If all pharmacokinetic criteria are not met, the third step is based on clinical endpoint studies. In this review, the scientific rationale of the European Medicines Agency guidance for the development of bioequivalent OIPs is reviewed with the focus on the development of bioequivalent OIPs in the EU. Indeed, we discuss the advantages and disadvantages of the weight-of-evidence and stepwise approaches. The evidence indicates that the EU guidance is robust and, unlike clinical endpoint studies, the pharmacokinetic studies are far more sensitive to measure the minor differences, i.e. deposition and absorption rates, in drug delivery from the test and reference products and, thus, should be best suited for assessing bioequivalence. The acceptance range of the 90% confidence intervals for pharmacokinetic bioequivalence (i.e. 80-125% for both the area under the plasma concentration-time curve and maximum plasma concentration) represent appropriately conservative margins for ensuring equivalent safety and efficacy of the test and reference products.

Inhaled Budesonide Does Not Affect Hypoxic Pulmonary Vasoconstriction at 4559 Meters of Altitude

Berger, Marc Moritz, Franziska Macholz, Peter Schmidt, Sebastian Fried, Tabea Perz, Daniel Dankl, Josef Niebauer, Peter Bärtsch, Heimo Mairbäurl, and Mahdi Sareban. Inhaled budesonide does not affect hypoxic pulmonary vasoconstriction at 4559 meters of altitude. High Alt Med Biol 19:52-59, 2018.-Oral intake of the corticosteroid dexamethasone has been shown to lower pulmonary artery pressure (PAP) and to prevent high-altitude pulmonary edema. This study tested whether inhalation of the corticosteroid budesonide attenuates PAP and right ventricular (RV) function after rapid ascent to 4559 m. In this prospective, randomized, double-blind, and placebo-controlled trial, 50 subjects were randomized into three groups to receive budesonide at 200 or 800 μg twice/day (n = 16 and 17, respectively) or placebo (n = 17). Inhalation was started 1 day before ascending from 1130 to 4559 m within 20 hours. Systolic PAP (SPAP) and RV function were assessed by transthoracic echocardiography at low altitude (423 m) and after 7, 20, 32, and 44 hours at 4559 m. Ascent to high altitude increased SPAP about 1.7-fold (p < 0.001), whereas RV function was preserved. There was no difference in SPAP and RV function between groups at low and high altitude (all p values >0.10). Capillary partial pressure of oxygen (PO₂) and carbon dioxide as well as the alveolar to arterial PO₂ difference were decreased at high altitude but not affected by budesonide. Prophylactic inhalation of budesonide does not attenuate high-altitude-induced pulmonary vasoconstriction and RV function after rapid ascent to 4559 m.

Considerations in establishing bioequivalence of inhaled compounds

INTRODUCTION

Generic inhalers are often perceived as inferior to their branded counterparts; however, they are safe and effective if they can meet the regulatory requirements. The approach to assess bioequivalence (BE) in oral dosage form products is not sufficient to address the complexities of inhalational products (e.g., patient-device interface); hence, more considerations are needed and caution should be applied in determining BE of inhaled compounds.

AREAS COVERED

This review outlines the evaluation process for generic inhalers, explores the regulatory approaches in BE assessment, and highlights the considerations and challenges in the current in vitro and in vivo approaches (lung deposition, pharmacokinetic, pharmacodynamic/clinical studies, and patient-device interface) for establishing BE of inhaled compounds.

EXPERT OPINION

The ultimate goals in this field are to establish uniformity in the regulatory approaches to speed the drug submission process in different regions, clear physicians' misconception of generic inhalers, and have meaningful clinical endpoints such as improvement in patient quality of life when compared to placebo and brand name drugs. As inhalational drugs become more common for other indications such as antibiotics, the technologies developed for inhaled compounds in the treatment of chronic pulmonary diseases may be extrapolated to these other agents.

Regulatory Approaches and Considerations in Establishing Bioequivalence of Inhaled Compounds

To be considered bioequivalent to their branded counterparts, generic drugs must meet the standards for bioequivalence (BE) described by the regulatory agencies. While BE of generic inhalational drugs can be evaluated using a similar approach as that for oral dosage from products or drugs that are delivered systemically, the approach is insufficient to address the complexities of inhalational products (e.g., localized site of action, device-patient interface). Therefore, more considerations are needed and caution should be applied when evaluating BE of inhaled compounds. The purpose of this review is to highlight the considerations and challenges in establishing BE of inhaled compounds by (1) outlining the current regulatory approaches (from Health Canada, the U.S. Food and Drug Administration, and the European Medicines Agency) to assess BE for subsequent entry inhaled products (SEIPs) and (2) reviewing the literature pertaining to testing considerations of SEIPs to establish BE.

Thin Air Resulting in High Pressure: Mountain Sickness and Hypoxia-Induced Pulmonary Hypertension

With rising altitude the partial pressure of oxygen falls. This phenomenon leads to hypobaric hypoxia at high altitude. Since more than 140 million people permanently live at heights above 2500 m and more than 35 million travel to these heights each year, understanding the mechanisms resulting in acute or chronic maladaptation of the human body to these circumstances is crucial. This review summarizes current knowledge of the body's acute response to these circumstances, possible complications and their treatment, and health care issues resulting from long-term exposure to high altitude. It furthermore describes the characteristic mechanisms of adaptation to life in hypobaric hypoxia expressed by the three major ethnic groups permanently dwelling at high altitude. We additionally summarize current knowledge regarding possible treatment options for hypoxia-induced pulmonary hypertension by reviewing in vitro, rodent, and human studies in this area of research.

Distinct Metabolic Profile of Inhaled Budesonide and Salbutamol in Asthmatic Children during Acute Exacerbation

Inhaled budesonide and salbutamol represent the most important and frequently used drugs in asthmatic children during acute exacerbation. However, there is still no consensus about their resulting metabolic derangements; thus, this study was conducted to determine the distinct metabolic profiles of these two drugs. A total of 69 children with asthma during acute exacerbation were included, and their serum and urine were investigated using high-resolution nuclear magnetic resonance (NMR). A metabolomics analysis was performed using a principal component analysis and orthogonal signal correction-partial least squares using SIMCA-P. The different metabolites were identified, and the distinct metabolic profiles were analysed using MetPA. A high-resolution NMR-based serum and urine metabolomics approach was established to study the overall metabolic changes after inhaled budesonide and salbutamol in asthmatic children during acute exacerbation. The perturbed metabolites included 22 different metabolites in the serum and 21 metabolites in the urine. Based on an integrated analysis, the changed metabolites included the following: increased 4-hydroxybutyrate, lactate, cis-aconitate, 5-hydroxyindoleacetate, taurine, trans-4-hydroxy-l-proline, tiglylglycine, 3-hydroxybutyrate, 3-methylhistidine, glucose, cis-aconitate, 2-deoxyinosine and 2-aminoadipate; and decreased alanine, glycerol, arginine, glycylproline, 2-hydroxy-3-methylvalerate, creatine, citrulline, glutamate, asparagine, 2-hydroxyvalerate, citrate, homoserine, histamine, sn-glycero-3-phosphocholine, sarcosine, ornithine, creatinine, glycine, isoleucine and trimethylamine N-oxide. The MetPA analysis revealed seven involved metabolic pathways: arginine and proline metabolism; taurine and hypotaurine metabolism; glycine, serine and threonine metabolism; glyoxylate and dicarboxylate metabolism; methane metabolism; citrate cycle; and pyruvate metabolism. The perturbed metabolic profiles suggest potential metabolic reprogramming associated with a combination treatment of inhaled budesonide and salbutamol in asthmatic children.

Inhaled corticosteroid dose response in asthma: Should we measure inflammation?

BACKGROUND

Inhaled corticosteroid (ICS) titration in asthma is primarily based on symptoms and pulmonary function. ICSs may not be increased on this basis despite residual airway inflammation.

OBJECTIVE

To compare the dose-response relationships of ICSs on measures of pulmonary function, symptoms, and inflammation in patients with persistent asthma.

METHODS

We performed a pooled post hoc analysis of 121 patients with mild to moderate asthma from 4 randomized clinical trials that incorporated an ICS dose ramp. Dose ramps were 0 to 200, 0 to 800, and 200 to 800 μg/d (beclomethasone equivalents). Outcome measures included spirometry, fractional exhaled nitric oxide, airway hyperresponsiveness (AHR), symptoms, serum eosinophilic cationic protein, and blood eosinophils.

RESULTS

We found a plateau beyond a small improvement at 0 to 200 μg for forced expiratory volume in 1 second: 3.3% (95% confidence interval [CI], 2.0%-4.7%) at 0 to 200 μg vs 0.3% (95% CI, -0.8% to 1.4%) 200 to 800 μg (P = .001). A similar plateau was seen for symptom improvement beyond 0 to 200 μg. Inflammatory and AHR outcomes revealed further room for improvement beyond low-dose ICSs. There was dose-related suppression (P < .001) for fractional exhaled nitric oxide: 40.4 ppb (95% CI, 34.7-46.9 ppb) for ICS free, 26.8 ppb (95% CI, 23.4-30.2 ppb) for 200 μg, and 20.8 ppb (95% CI, 18.8-23.1 ppb) for 800 μg. Eosinophilic cationic protein concentration was significantly reduced with both higher dose ramps. Eosinophil counts also improved across all 3 dose ramps, with dose separation of 370/μL (95% CI, 280-450/μL) for ICS free vs 250/μL (95% CI, 200-300/μL) 800 μg (P = .03). AHR improved with all 3 dose ramps, with greater improvement at lower doses for indirect vs direct challenges.

CONCLUSION

ICS dose response may extend beyond low dose for inflammation and AHR but not symptoms or spirometry. Further study is required to identify whether this correlates with suboptimal longitudinal asthma control.

TRIAL REGISTRATION

ClinicalTrials.gov Identifiers: NCT00667992, NCT00995657, NCT01216579, NCT01544634.

Systematic Review of Inhaled Bronchodilator and Corticosteroid Therapies in Infants with Bronchopulmonary Dysplasia: Implications and Future Directions

BACKGROUND

There is much debate surrounding the use of inhaled bronchodilators and corticosteroids for infants with bronchopulmonary dysplasia (BPD).

OBJECTIVE

The objective of this systematic review was to identify strengths and knowledge gaps in the literature regarding inhaled therapies in BPD and guide future research to improve long-termoutcomes.

METHODS

The databases of Academic Search Complete, CINAHL, PUBMED/MEDLINE, and Scopus were searched for studies that evaluated both acute and long-term clinical outcomes related to the delivery and therapeutic efficacy of inhaled beta-agonists, anticholinergics and corticosteroids in infants with developing and/or established BPD.

RESULTS

Of 181 articles, 22 met inclusion criteria for review. Five evaluated beta-agonist therapies (n = 84, weighted gestational age (GA) of 27.1(26-30) weeks, weighted birth weight (BW) of 974(843-1310) grams, weighted post menstrual age (PMA) of 34.8(28-39) weeks, and weighted age of 53(15-86) days old at the time of evaluation). Fourteen evaluated inhaled corticosteroids (n = 2383, GA 26.2(26-29) weeks, weighted BW of 853(760-1114) grams, weighted PMA of 27.0(26-31) weeks, and weighted age of 6(0-45) days old at time of evaluation). Three evaluated combination therapies (n = 198, weighted GA of 27.8(27-29) weeks, weighted BW of 1057(898-1247) grams, weighted PMA of 30.7(29-45) weeks, and age 20(10-111) days old at time of evaluation).

CONCLUSION

Whether inhaled bronchodilators and inhaled corticosteroids improve long-term outcomes in BPD remains unclear. Literature regarding these therapies mostly addresses evolving BPD. There appears to be heterogeneity in treatment responses, and may be related to varying modes of administration. Further research is needed to evaluate inhaled therapies in infants with severe BPD. Such investigations should focus on appropriate definitions of disease and subject selection, timing of therapies, and new drugs, devices and delivery methods as compared to traditional methods across all modalities of respiratory support, in addition to the assessment of long-term outcomes of initial responders.

A European perspective on orally inhaled products: in vitro requirements for a biowaiver

This article describes the European Union stepwise approach used for the development and assessment of second-entry orally inhaled products. This approach is similar to the approach used for systemically acting products. In some cases, in vitro data can be used to show equivalence without performing in vivo studies (e.g., solutions for nebulization in the case of inhalation products, and oral solutions or Biopharmaceutics Classification System-based biowaivers in the case of systemically acting drugs). If equivalence cannot be shown in the first step, the Applicant can show equivalence in a second step by means of conventional pharmacokinetic bioequivalence studies to assess directly systemic exposure and lung deposition indirectly. The dose absorbed from the lungs should be distinguished from the dose absorbed from the gastrointestinal tract. Then the fraction of dose absorbed (area under the curve) represents the dose that reached the site of action, and the peak exposure gives information on the pattern of deposition within the lungs. This information is more discriminative than any pharmacodynamic or clinical endpoint, because these have flat dose-response curves. If equivalence is not shown with pharmacokinetic data, the Applicant can decide to show equivalence by means of pharmacodynamic or clinical trials, but assay sensitivity must be demonstrated within the study and relative potency should be estimated. This article focuses on the in vitro requirements applicable in the European Union for a waiver of in vivo studies and for waiving studies with all drug product strengths or pharmacokinetic studies in patients. The reasons why in the European Union in vitro data alone can be used to show equivalence are discussed, and some examples are given.

The potential role of direct and indirect bronchial challenge testing to identify overtreatment of community managed asthma

BACKGROUND

Although airway hyperresponsiveness (AHR) is a defining feature of asthma pathophysiology, bronchial challenge testing is not routinely used in primary care asthma management.

OBJECTIVE

The aim of this study was to evaluate the potential role of direct (methacholine) and indirect (mannitol) challenge testing in community managed asthma.

METHODS

Patients currently treated for asthma from Tayside and Fife were identified by the Health Informatics Centre (HIC) and invited to take part in the study. At screening, the following tests were carried out: spirometry, methacholine and mannitol challenge, exhaled nitric oxide (FeNO); Asthma Control Questionnaire (ACQ) and Mini Asthma Quality of Life Questionnaire (AQLQ).

RESULTS

A total of 3388 asthmatics were initially identified by HIC with 423 positive responses and 123 completing the study. Seventy percent had either a positive methacholine (PC20  < 8 mg/mL) or mannitol challenge (PD15  < 635 mg), and 30% were non-responsive to both challenges. Fourteen percent of methacholine responders (n = 74) were negative to mannitol, and 16% of mannitol responders (n = 76) were negative to methacholine. Spirometry, FeNO, ACQ and AQLQ were significantly better in the non-responder group who were exposed to high-dose inhaled corticosteroids and frequent long-acting beta-agonists.

CONCLUSIONS AND CLINICAL RELEVANCE

We found that 30% of unselected patients with community managed asthma were challenge negative and could be potentially misdiagnosed or overtreated, in turn suggesting the need for supervised step-down.

Regulatory Considerations for Approval of Generic Inhalation Drug Products in the US, EU, Brazil, China, and India

This article describes regulatory approaches for approval of "generic" orally inhaled drug products (OIDPs) in the United States, European Union, Brazil, China and India. While registration of a generic OIDP in any given market may require some documentation of the formulation and device similarity to the "original" product as well as comparative testing of in vitro characteristics and in vivo performance, the specific documentation approaches, tests and acceptance criteria vary by the country. This divergence is due to several factors, including unique cultural, historical, legal and economic circumstances of each region; the diverse healthcare and regulatory systems; the different definitions of key terms such as "generic" and "reference" drug; the acknowledged absence of in vitro in vivo correlations for OIDPs; and the scientific and statistical issues related to OIDP testing (such as how best to account for the batch-to-batch variability of the Reference product, whether to use average bioequivalence or population bioequivalence in the statistical analysis of results, whether to use healthy volunteers or patients for pharmacokinetic studies, and which pharmacodynamic or clinical end-points should be used). As a result of this discrepancy, there are ample opportunities for the regulatory and scientific communities around the world to collaborate in developing more consistent, better aligned, science-based approaches. Moving in that direction will require both further research and further open discussion of the pros and cons of various approaches.

Inhaled budesonide and oral dexamethasone prevent acute mountain sickness

BACKGROUND

This double-blind, randomized controlled trial aimed to investigate inhaled budesonide and oral dexamethasone compared with placebo for their prophylactic efficacy against acute mountain sickness after acute high-altitude exposure.

METHODS

There were 138 healthy young male lowland residents recruited and randomly assigned to receive inhaled budesonide (200 μg, twice a day [bid]), oral dexamethasone (4 mg, bid), or placebo (46 in each group). They traveled to 3900 m altitude from 400 m by car. Medication started 1 day before high-altitude exposure and continued until the third day of exposure. Primary outcome measure was the incidence of acute mountain sickness after exposure.

RESULTS

One hundred twenty-four subjects completed the study (42, 39, and 43 in the budesonide, dexamethasone, and placebo groups, respectively). Demographic characteristics were comparable among the 3 groups. After high-altitude exposure, significantly fewer participants in the budesonide (23.81%) and dexamethasone (30.77%) groups developed acute mountain sickness compared with participants receiving placebo (60.46%) (P = .0006 and P = .0071, respectively). Both the budesonide and dexamethasone groups had lower heart rate and higher pulse oxygen saturation (SpO2) than the placebo group at altitude. Only the budesonide group demonstrated less deterioration in forced vital capacity and sleep quality than the placebo group. Four subjects in the dexamethasone group reported adverse reactions.

CONCLUSIONS

Both inhaled budesonide (200 μg, bid) and oral dexamethasone (4 mg, bid) were effective for the prevention of acute mountain sickness, especially its severe form, compared with placebo. Budesonide caused fewer adverse reactions than dexamethasone.

Evaluation of in vitro and in vivo flow rate dependency of budesonide/formoterol Easyhaler(®)

BACKGROUND

The Easyhaler(®) (EH) device-metered dry powder inhaler containing budesonide and formoterol is being developed for asthma and chronic obstructive pulmonary disease (COPD). As a part of product optimization, a series of in vitro and in vivo studies on flow rate dependency were carried out.

METHODS

Inspiratory flow parameters via EH and Symbicort(®) Turbuhaler(®) (TH) inhalers were evaluated in 187 patients with asthma and COPD. The 10(th), 50(th), and 90(th) percentile flow rates achieved by patients were utilized to study in vitro flow rate dependency of budesonide/formoterol EH and Symbicort TH. In addition, an exploratory pharmacokinetic study on pulmonary deposition of active substances for budesonide/formoterol EH in healthy volunteers was performed.

RESULTS

Mean inspiratory flow rates through EH were 64 and 56 L/min in asthmatics and COPD patients, and through TH 79 and 72 L/min, respectively. Children with asthma had marginally lower PIF values than the adults. The inspiratory volumes were similar in all groups between the inhalers. Using weighted 10(th), 50(th), and 90(th) percentile flows the in vitro delivered doses (DDs) and fine particle doses (FPDs) for EH were rather independent of flow as 98% of the median flow DDs and 89%-93% of FPDs were delivered already at 10(th) percentile air flow. Using±15% limits, EH and TH had similar flow rate dependency profiles between 10(th) and 90(th) percentile flows. The pharmacokinetic study with budesonide/formoterol EH in healthy subjects (n=16) revealed a trend for a flow-dependent increase in lung deposition for both budesonide and formoterol.

CONCLUSIONS

Comparable in vitro flow rate dependency between budesonide/formoterol EH and Symbicort TH was found using the range of clinically relevant flow rates. The results of the pharmacokinetic study were in accordance with the in vitro results showing only a trend of flow rate-dependant increase in lung deposition of active substances with EH.

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.

Clinical equivalence of budesonide dry powder inhaler and pressurized metered dose inhaler

INTRODUCTION

A delivery device is the most important factor that determines the local/systemic bioavailability of inhaled corticosteroids. Dry powder inhalers (DPIs) and pressurized metered dose inhalers (pMDIs) are the most commonly used delivery devices for localized drug delivery to the airways.

OBJECTIVE

This study was to compare the clinical equivalence of budesonide delivered by the Pulmicort Turbuhaler (DPI) and the Aeronide inhaler (pMDI).

MATERIALS AND METHODS

The two inhalers were compared for their pharmaceutical equivalence and clinical equivalence. The in vitro test included the uniformity of the delivered dose and determination of the aerodynamic particle size of budesonide. The in vivo test was carried out in 36 patients with mild to moderate asthma. This was a randomized, single-blinded study conducted for a period of 3 months. This included assessment of the spirometric parameters [forced expiratory volume in 1 s (FEV1), forced vital capacity (FVC), peak expiratory flow rate (PEFR), forced expiratory flow 25-75% (FEF25-75)], the severity of asthma symptoms, adverse events, frequency of short-acting inhaled bronchodilator usage and measurement of urinary cortisol levels.

RESULTS

The aerodynamic particle size was slightly different between the two inhalers (2.3 ± 0.2 µm for Pulmicort Turbuhaler and 2.2 ± 0.2 µm for Aeronide inhaler). Both inhalers passed the uniformity of delivered dose (95.4% and 97.4%) specified in the British Pharmacopoeia. There was no statistically significant difference observed between the two inhalers in terms of the spirometric parameters, symptom-free days, frequency of bronchodilator usage and the level of urinary cortisol.

CONCLUSION

In addition to pharmaceutical equivalence, no clinical difference observed between the two budesonide inhalers.

Validated assay for the simultaneous determination of cortisol and budesonide in human plasma using ultra high performance liquid chromatography-tandem mass spectrometry

An ultra high performance liquid chromatography-tandem mass spectrometry (UHPLC/MS/MS) method was developed and validated for the quantification of cortisol and budesonide in human plasma. Charcoal stripped human plasma was used as the blank matrix during validation. Cortisol, budesonide, and dexamethasone (internal standard) were extracted from human plasma with methyl-tert-butyl ether, and the chromatographic separation of the peaks was achieved using a Waters Acquity UPLC BEH C18, 1.7 μm, 2.1 mm × 50 mm column with a run time of 4.0 min. Cortisol, budesonide, and dexamethasone were monitored at the total ion current of their respective multiple reaction monitoring transition signals. The UHPLC/MS/MS system consisted of an Agilent 1290 Infinity ultra high performance liquid chromatograph coupled with an AB Sciex Qtrap(®) 5500 hybrid linear ion-trap triple quadrupole mass spectrometer. The method was validated for accuracy, precision, linearity, range, selectivity, lower limit of quantification (LLOQ), recovery, matrix effect, dilution integrity, and evaluation of carry-over. All validation parameters met the acceptance criteria according to regulatory guidelines. The LLOQ was 1.0 ng/mL for both compounds requiring 100 μL of sample. To our knowledge, this is the first validated LC/MS/MS method for the simultaneous quantitative analysis of cortisol and budesonide in human plasma. The method was applied successfully in a clinical investigation of the impact of nasally administered Pulmicort (budesonide) on the hypothalamic-pituitary-adrenal axis of patients with chronic rhinosinusitis.

Bioequivalence of inhaled drugs: fundamentals, challenges and perspectives

Interest in bioequivalence (BE) of inhaled drugs derives largely from the desire to offer generic substitutes to successful drug products. The complexity of aerosol dosage forms renders them difficult to mimic and raises questions regarding definitions of similarities and those properties that must be controlled to guarantee both the quality and the efficacy of the product. Despite a high level of enthusiasm to identify and control desirable properties there is no clear guidance, regulatory or scientific, for the variety of aerosol dosage forms, on practical measures of BE from which products can be developed. As more data on the pharmaceutical and clinical relevance of various techniques, as described in this review, become available, it is likely that a path to the demonstration of BE will become evident. In the meantime, debate on this topic will continue.

Equivalence considerations for orally inhaled products for local action-ISAM/IPAC-RS European Workshop report

The purpose of this article is to document the discussions at the 2010 European Workshop on Equivalence Determinations for Orally Inhaled Drugs for Local Action, cohosted by the International Society for Aerosols in Medicine (ISAM) and the International Pharmaceutical Consortium on Regulation and Science (IPAC-RS). The article summarizes current regulatory approaches in Europe, the United States, and Canada, and presents points of consensus as well as ongoing debate in the four major areas: in vitro testing, pharmacokinetic and pharmacodynamic studies, and device similarity. Specific issues in need of further research and discussion are also identified.

Does body mass index influence responsiveness to inhaled corticosteroids in persistent asthma?

BACKGROUND

Although the relationship between asthma and obesity has been extensively explored, the effect of body mass index (BMI) on the dose-response relationship to inhaled corticosteroids (ICS) has received little attention.

OBJECTIVE

To assess the dose-response of inhaled budesonide on outcome measures of asthma between overweight and normal weight patients with persistent asthma.

METHODS

Seventy-two patients with mild to moderate persistent asthma from a post hoc analysis of previously reported trial data were divided into 2 groups: overweight, BMI 25 kg/m(2) or higher; normal weight, BMI less than 25 kg/m(2). Each group received 4 weeks' treatment with inhaled (hydrofluoroalkane) budesonide 200 μg/day then 800 μg/day with ICS washout pretreatment. Outcome measures forced expiratory volume in 1 second (FEV(1)), fractional exhaled nitric oxide (FeNO), methacholine PC20, total daily asthma symptom score, and overnight urinary cortisol/creatinine ratio were performed at baseline and after each dose.

RESULTS

Significantly greater improvements were seen in the normal weight group for both FeNO and symptom responses at 0 to 200 μg and 0 to 800 μg ICS doses (as change from baseline), compared with the overweight group: FeNO 0 to 200 μg, P = .002; 0 to 800 μg, P = .045; symptoms 0 to 200 μg, P = .002; 0 to 800 μg, P = .013. A trend also was seen toward attenuated cortisol suppression in overweight subjects at 0 to 800 μg (P = .06), but no significant difference was seen at either dose in FEV(1) and methacholine PC20 between weight groups.

CONCLUSION

Overweight patients with persistent asthma may have attenuated symptom and FeNO dose responses to inhaled budesonide compared with normal weight patients with asthma, with no differences in FEV(1) or methacholine PC20 between groups. Attenuated cortisol suppression in the overweight group may be the clue to this difference, alluding to reduced peripheral lung deposition or absorption in overweight patients with asthma.