Relative bioavailability of budesonide/glycopyrrolate/formoterol fumarate triple therapy delivered using next generation propellants with low global warming potential.

INTRODUCTION: The climate crisis poses an immediate threat to human health and well-being, demanding urgent adaptions across sectors, including healthcare. The development of pressurized metered dose inhalers (MDIs) with greater sensitivity to the climate emergency using novel propellants with lower global warming potentials (GWPs), but comparable pharmacokinetic (PK) parameters to currently marketed MDIs, is a vital step toward reducing the impact of healthcare for respiratory disorders on climate change. This study evaluated the relative bioavailabilities of the individual components of a fixed-dose combination of budesonide/glycopyrrolate/formoterol fumarate (BGF) 160/9/4.8 µg per actuation between three different propellant formulations. METHODS: Healthy male participants (aged 18-60 years) were randomized into a single-blind, three-period, single-dose, single-center, crossover study (NCT04600505). The PK and safety and tolerability profiles of BGF MDI formulated with two novel propellants with low GWP (hydrofluoroolefin-1234ze [HFO]; hydrofluorocarbon-152a [HFC]) were compared with BGF MDI formulated with the propellant used in the currently marketed reference product (hydrofluoroalkane-134a [HFA]). The study included a screening period, three treatment periods (with 3- to 7-day washout periods between each dose), and a follow-up. The primary PK parameters assessed were maximum observed plasma concentration (Cmax), area under the plasma concentration curve (AUC) from time zero extrapolated to infinity (AUCinf), and AUC from time zero to the time of the last quantifiable analyte concentration (AUClast). The study was not powered to statistically demonstrate bioequivalence. RESULTS: Forty-seven participants completed the study, and 24 participants were evaluable for PK assessments. Systemic exposure, based on geometric mean ratios (90% confidence interval), to each BGF component from the test propellants delivered in a standard MDI was comparable with the reference propellant for AUClast (HFO vs. HFA: budesonide, 107.30 [94.53, 121.90]; glycopyrrolate, 106.10 [86.18, 130.60]; formoterol, 98.13 [86.44, 111.40]; HFC vs. HFA: budesonide, 98.80 [84.59, 115.40]; glycopyrrolate, 99.71 [80.84, 123.00]; formoterol, 107.00 [88.82, 128.90]); AUCinf (where evaluable) and Cmax followed the same trend. There were no serious adverse events or adverse events leading to treatment discontinuation. No new safety signals were observed. CONCLUSIONS: Systemic BGF component exposure was similar for both test propellants (HFO and HFC) compared with the HFA reference propellant, with an acceptable safety profile in the studied population. Therefore, both novel low GWP propellants show strong potential as candidates for development of MDIs with greater sensitivity to the climate crisis, a vital step toward ameliorating the detrimental impact of healthcare on the environment. Further investigation in larger studies is warranted.

Correct use and ease of use of a placebo dry powder inhaler in subjects with asthma and chronic obstructive pulmonary disease.

Correct use and ease of use of a placebo dry powder inhaler was evaluated in two single-arm, United States-multicenter, phase-IV studies in adults with asthma ( n = 259) or chronic obstructive pulmonary disease (COPD; n = 278) who were receiving maintenance inhaler therapy. Subjects demonstrating correct placebo inhaler use within three attempts at screening were instructed to take once-daily inhalations from the inhaler for 28 ± 2 days (continuing usual maintenance), followed by randomization to complete one of two versions of an ease-of-use questionnaire and reassessment for correct inhaler use. At study end, 96% asthma/93% COPD subjects rated the placebo inhaler as "easy" or "very easy" to use while demonstrating correct use. Furthermore, 99% asthma/99% COPD subjects indicated it was "easy" or "very easy" to determine number of doses remaining, and 81%/84%, respectively, indicated they would be "likely" or "very likely" to request their current medication in the inhaler, if available. Adverse event (AE) rates were 12% asthma/15% COPD, most frequently headache (3%/3%). Treatment-related AEs were reported in one subject with asthma (cough) and four subjects with COPD (cough, n = 3; back pain, n = 1). At study end, most subjects with asthma or COPD operated the placebo inhaler correctly and found it easy to use.

A Randomized Clinical Trial Comparing the ELLIPTA and HandiHaler Dry Powder Inhalers in Patients With COPD: Inhaler-Specific Attributes and Overall Patient Preference.

This randomised, open-label, cross-over, placebo-containing inhaler study assessed patient preference indicators for ELLIPTA and HandiHaler dry powder inhalers in patients with COPD (NCT02786927; GSK identifier: 204983). The primary objective of this study was to assess patient preference between ELLIPTA and HandiHaler based on the number of steps needed to use the inhaler. Eligible patients ≥40 years of age with COPD were randomised 1:1 to receive their current COPD medication plus a placebo-containing ELLIPTA or HandiHaler inhaler once daily for 7 ± 2 days (treatment period 1); this was followed by a 7 ± 2-day placebo treatment with the alternative inhaler. A 5-item questionnaire assessed inhaler-related patient preferences. A total of 212 patients (mean age, 65.1 years) were enrolled at 22 US sites; 73% had a COPD duration ≥5 years. Median (range) exposure was 8 ( 5 , 13 ) days for ELLIPTA and 8 ( 1 , 16) days for HandiHaler. Significantly more patients preferred ELLIPTA to HandiHaler in terms of the number of steps to use and all secondary attributes (size, comfort of the mouthpiece, remaining doses, and ease of use of the two inhalers; all p < 0.001). Similar results were observed irrespective of the order of inhaler use. Eighteen patients (8%) reported at least one AE and two (<1%) patients reported four non-fatal SAEs; none were related to the study treatment. Patient attitude toward a particular inhaler and their experiences in using it can affect adherence to therapy, which can in turn strongly influence effectiveness of inhaled medications. This study uses a robust methodology to assess patient preference.

Correct use and ease-of-use of placebo ELLIPTA dry-powder inhaler in adult patients with chronic obstructive pulmonary disease.

BACKGROUND: Inhaler technique errors are common in chronic obstructive pulmonary disease (COPD) treatment, potentially leading to poor disease management. Our pooled analysis approach assessed correct use and ease-of-use of a placebo ELLIPTA dry-powder inhaler (DPI) in patients with COPD. METHODS: Adults with COPD from open-label/non-blinded studies evaluating a placebo ELLIPTA DPI and reporting outcomes of correct use (based on the ELLIPTA DPI patient information leaflet [PIL]) and/or ease-of-use were included. Correct use and ease-of use at study end were primary and secondary endpoints, respectively. Data from patients in the placebo ELLIPTA DPI arm of each study were pooled, and the intent-to-treat (ITT) population was used for all analyses. RESULTS: Four placebo ELLIPTA DPI studies, reporting correct use (n = 4) and ease-of-use (n = 2), were included in the analysis. The ITT population comprised 1232 patients (mean age 66.2 years). For the primary endpoint, 80.1% (n = 975/1217) of patients demonstrated correct use at study end (95% confidence interval [CI]: 77.8%-82.3%). For the secondary endpoint, 95.7% (n = 797/833) of patients rated placebo ELLIPTA DPI use "easy"/"very easy" at study end (95% CI: 94.1%-97.0%). Correct use and "easy"/"very easy" user ratings remained high across younger (40-64 years) and older (≥65 years) age groups. CONCLUSIONS: Across age groups, most patients used the placebo ELLIPTA DPI correctly and rated it "easy"/"very easy" to use. Consistent with the Global Initiative for Chronic Obstructive Lung Disease 2021 report, our findings emphasize that proper training and clear instructions on PILs are important for optimal inhaler use.

Peak Inspiratory Flow Rate in COPD: An Analysis of Clinical Trial and Real-World Data.

BACKGROUND: The influence of peak inspiratory flow (PIF) on dose delivery from dry powder inhalers (DPIs) and association with treatment efficacy in patients with chronic obstructive pulmonary disease (COPD) has not been fully determined. In vitro studies have demonstrated adequate dose delivery through ELLIPTA DPI at PIF ≥30 L/min. This analysis of two clinical trials and a real-world population of COPD patients determined spirometric PIF distribution, and explored the relationship between PIF and outcomes in the trials. METHODS: The replicate Phase IV, 12-week, randomized, double-blind 207608/207609 (NCT03478683/NCT03478696) trials evaluated fluticasone furoate/umeclidinium/vilanterol via ELLIPTA DPI versus budesonide/formoterol+tiotropium in COPD patients. This post hoc analysis assessed spirometric PIF distribution at screening and relationship between PIF and lung function outcomes in the pooled 207608/207609 population. Spirometric PIF distributions in a real-world population of COPD patients were evaluated by retrospective analysis of the Kaiser Permanente Northwest (KPNW) database to assess similarities between clinical trial and real-world populations. RESULTS: A total of 1460 (207608/207609) and 3282 (KPNW) patients were included. There was considerable overlap between spirometric PIF distributions for both populations. Overall, 99.7% and 99.8% of the 207608/207609 and KPNW populations, respectively, reported spirometric PIF ≥50 L/min, estimated as equivalent to ELLIPTA PIFR ≥30 L/min. In the 207608/207609 combined analysis, there was no significant interaction between spirometric PIF and treatment for lung function endpoints, indicating treatment effect is independent of PIF. CONCLUSION: Nearly all COPD patients in the 207608/207609 and KPNW populations achieved spirometric PIF values estimated as equivalent to PIFR of ≥30 L/min through the ELLIPTA DPI. Lack of correlation between spirometric PIF at screening and treatment efficacy aligns with consistent dose performance from the ELLIPTA DPI across a wide range of PIFs, achieved by patients with COPD of all severities.

The evaluation of the correct use and ease-of use of the ELLIPTA DPI in children with asthma.

RATIONALE: Asthma studies show many children use inhalers incorrectly even after instruction. For two age groups of children with asthma, we determined the proportions who used the once-daily ELLIPTA dry-powder inhaler (DPI) correctly, and who found it easy to use. METHODS: This was a multicenter, single-arm, stratified, open-label, placebo study (NCT03478657). Children aged 5-7 and 8-11 years were trained in, and required to demonstrate, correct placebo ELLIPTA DPI use at their first clinic visit. The inhaler was used at home once daily for 28 ± 2 days. On returning to the clinic, children were randomized to an age-appropriate, ease-of-use questionnaire that had been developed and validated previously, and which rated the inhaler as "easy" or "hard" to use. Following questionnaire completion, children were then asked to demonstrate correct inhaler use. Correct use and ease-of use were assessed in each age group (co-primary endpoints) and overall (secondary endpoints). RESULTS: Of 222 enrolled children, 221 completed the study. Among children aged 5-7 years, 92% (n = 81/88) demonstrated correct ELLIPTA use on their first attempt, compared with 93% (n = 124/133) aged 8-11 years. Of these children, 98% (5-7 years: n = 79/81; 8-11 years: n = 121/124) rated the inhaler easy to use. Overall, 93% (n = 205/221) demonstrated correct inhaler use on their first attempt, and 98% (n = 200/205) rated it easy to use. CONCLUSION: ELLIPTA DPI was used correctly and easily by most children on their first attempt without additional training.

Pilot Study of a Patient Experience with an ELLIPTA Inhaler Electronic Medication Monitor and Associated Integrated System: A Prospective Observational Study Using the COPD Patient-Powered Research Network.

BACKGROUND: Electronic medication monitors (EMMs) are associated with decreased rescue inhaler use, symptom burden, and increased medication adherence in asthma. However, the use of EMMs in people with chronic obstructive pulmonary disease (COPD) using the ELLIPTA dry powder inhaler has not been studied. METHODS: This was an open-label, single-arm, prospective observational study of EMMs and associated application (app) use over 12 weeks and up to 24 weeks (April-October 2019) in people with self-reported COPD aged ≥40 years enrolled in the COPD Patient-Powered Research Network, using an ELLIPTA inhaler. The primary outcome was daily active use of the app over 12 weeks. Treatment adherence, rescue inhaler use, and participant satisfaction were assessed over the same period. RESULTS: Among the 122 participants, mean (standard deviation [SD]) proportion of days participants opened the app was 59.5% (31.4), 51.1% (33.5) and 41.3% (34.2) for Days 1-30, 31-60 and 61-90, respectively. Mean (SD) adherence to maintenance medication remained stable: 80.2% (22.7) and 79.9% (26.7) for Days 1-30 and 61-90, respectively. In participants using a rescue inhaler and EMM, mean (SD) rescue-free days increased from 18.5 (10.0; Days 1-30, n=51) to 21.4 (9.6; Days 61-90, n=48). Participants reported high levels of confidence in using the EMM, valued app reminders highly and reported high system satisfaction (mean [SD] scale: 1=low, 5=high; 4.6 [1.1], 4.3 [1.1] and 4.1 [1.1], respectively). CONCLUSIONS: Use of an ELLIPTA EMM with frequent app engagement, high participant satisfaction and decreased rescue medication use may aid COPD management.

ELLIPTA Versus DISKUS plus HandiHaler in COPD: A Randomized, Open-Label, Crossover Study in a Clinical Trial Setting.

BACKGROUND: Inhaler errors among patients with chronic obstructive pulmonary disease (COPD) can reduce treatment efficacy. METHODS: This randomized, open-label, crossover study evaluated correct use of ELLIPTA versus DISKUS plus HandiHaler. Participants with COPD attended at least 3 study visits (Day 1 [Visit 1], Day 28 [Visit 2], and Day 56 [Visit 3]). Inhalers contained placebo; usual maintenance medication was continued. Participants were randomized to an inhaler sequence (ELLIPTA then DISKUS plus HandiHaler, or the reverse) and preference questionnaire at Visit 1. Participants read the instructions for use in the approved prescribing information for their inhaler(s) and correct use was assessed at Visit 1 (verbal guidance provided if required). Correct use was reassessed at Visit 2, and with the next inhaler(s) at Visit 3. Primary endpoint was the proportion of participants demonstrating correct use (0 errors) with the assigned inhaler(s) after 28 days. RESULTS: A greater proportion of study participants (n = 217) correctly used ELLIPTA (96%) versus DISKUS plus HandiHaler (87%) after 28 days. The odds of demonstrating correct use with ELLIPTA were 6.88 times that of DISKUS plus HandiHaler (p < 0.001). Overall, > 99% of participants made 0 critical errors (errors leading to no or significantly reduced medication inhaled) with ELLIPTA versus 89% with DISKUS plus HandiHaler after 28 days. ELLIPTA was the patient-preferred option versus DISKUS plus HandiHaler or no preference (p < 0.001). CONCLUSIONS: Delivery of COPD maintenance therapy via ELLIPTA demonstrates higher correct use rates and lower critical error rates compared with DISKUS plus HandiHaler.

Critical Error Frequency and the Impact of Training with Inhalers Commonly used for Maintenance Treatment in Chronic Obstructive Pulmonary Disease.

Introduction: Training in correct inhaler use, ideally in person or by video demonstration, can minimize errors but is rarely provided in clinics. This open-label, low-intervention study evaluated critical error rates with dry-powder inhalers (DPIs), before and after training, in patients with chronic obstructive pulmonary disease. Methods: Patients prescribed an inhaled corticosteroid (ICS)/long-acting ß2-agonist (LABA) (ELLIPTA, Turbuhaler, or DISKUS), long-acting muscarinic antagonist (LAMA)/LABA (ELLIPTA or Breezhaler), or LAMA-only DPI (ELLIPTA, HandiHaler, or Breezhaler) were enrolled. Critical errors were assessed before training (Visit 1 [V1]; primary endpoint) and 6 weeks thereafter (Visit 2 [V2]; secondary endpoint). Logistic regression models were used to calculate odds ratios (ORs) for between-group comparisons. Results: The intent-to-treat population comprised 450 patients. At V1, fewer patients made ≥1 critical error with ELLIPTA (10%) versus other ICS/LABA DPIs (Turbuhaler: 40%, OR 4.66, P=0.005; DISKUS: 26%, OR 2.48, P=0.114) and other LAMA or LAMA/LABA DPIs (HandiHaler: 34%, OR 3.50, P=0.026; Breezhaler: 33%, OR 3.94, P=0.012). Critical error rates with the primary ICS/LABA DPI were not significantly different between ELLIPTA ICS/LABA (10%) and ICS/LABA plus LAMA groups (12-25%). Critical errors with the primary ICS/LABA DPI occurred less frequently with ELLIPTA ICS/LABA with or without LAMA (11%) versus Turbuhaler ICS/LABA with or without LAMA (39%, OR 3.99, P<0.001) and DISKUS ICS/LABA with or without LAMA (26%, OR 2.18, P=0.069). Simulating single-inhaler versus multiple-inhaler triple therapy, critical error rates were lower with ELLIPTA fluticasone furoate/vilanterol (FF/VI; 10%) versus ELLIPTA FF/VI plus LAMA (22%), considering errors with either DPI (OR 2.50, P=0.108). At V2, critical error rates decreased for all DPIs/groups, reaching zero only for ELLIPTA. Between-group comparisons were similar to V1. Conclusion: Fewer patients made critical errors with ELLIPTA versus other ICS/LABA, and LAMA or LAMA/LABA DPIs. The effect of "verbal" training highlights its importance for reducing critical errors with common DPIs.

ELLIPTA Dry Powder Versus Metered-Dose Inhalers in an Optimized Clinical Trial Setting.

BACKGROUND: Reduced error rates have been demonstrated with the ELLIPTA inhaler versus other commonly used devices. OBJECTIVE: This phase IV, randomized, crossover study evaluated correct use of ELLIPTA compared with 2 commonly prescribed metered-dose inhalers (MDIs) in adults with asthma and optimized inhaler technique. METHODS: The study comprised 2 crossover substudies (ELLIPTA vs MDI-1 and ELLIPTA vs MDI-2). Inhaler use was assessed at the start of each period, following instruction from a health care professional, and after 28 days of use without instruction. Data for each inhaler were pooled within substudies, irrespective of treatment sequence; study objectives were addressed in each substudy. The primary end point, percentage of participants making 0 errors after 28 days of use, was analyzed separately for each substudy using a Mainland-Gart test for each ELLIPTA versus MDI comparison. RESULTS: Correct use rates after 28 days were higher with ELLIPTA than with MDI-1 and MDI-2 (ELLIPTA vs MDI-1, 96% vs 84%; ELLIPTA vs MDI-2, 98% vs 91%). Among discordant cases, statistically significantly more participants correctly used ELLIPTA but made 1 or more overall error with MDIs than did those who correctly used the MDIs but made 1 or more overall error using ELLIPTA (87% vs 13% in both substudies; P < .001 and P = .007 for ELLIPTA vs MDI-1 and ELLIPTA vs MDI-2, respectively). More participants made multiple device errors with MDIs than with ELLIPTA. CONCLUSIONS: Inhaler technique can be optimized in trial settings. In such settings, ELLIPTA is associated with higher rates of correct use and lower error rates than are MDIs.

Use of clinical characteristics to predict spirometric classification of obstructive lung disease.

Background: There is no consensus on how to define patients with symptoms of asthma and chronic obstructive pulmonary disease (COPD). A diagnosis of asthma-COPD overlap (ACO) syndrome has been proposed, but its value is debated. This study (GSK Study 201703 [NCT02302417]) investigated the ability of statistical modeling approaches to define distinct disease groups in patients with obstructive lung disease (OLD) using medical history and spirometric data. Methods: Patients aged ≥18 years with diagnoses of asthma and/or COPD were categorized into three groups: 1) asthma (nonobstructive; reversible), 2) ACO (obstructive; reversible), and 3) COPD (obstructive; nonreversible). Obstruction was defined as a post-bronchodilator forced expiratory volume in 1 second (FEV1)/forced vital capacity <0.7, and reversibility as a post-albuterol increase in FEV1 ≥200 mL and ≥12%. A primary model (PM), based on patients' responses to a health care practitioner-administered questionnaire, was developed using multinomial logistic regression modeling. Other multivariate statistical analysis models for identifying asthma and COPD as distinct entities were developed and assessed using receiver operating characteristic (ROC) analysis. Partial least squares discriminant analysis (PLS-DA) assessed the degree of overlap between groups. Results: The PM predicted spirometric classifications with modest sensitivity. Other analysis models performed with high discrimination (area under the ROC curve: asthma model, 0.94; COPD model, 0.87). PLS-DA identified distinct phenotypic groups corresponding to asthma and COPD. Conclusion: Within the OLD spectrum, patients with asthma or COPD can be identified as two distinct groups with a high degree of precision. Patients outside these classifications do not constitute a homogeneous group.

The effect of umeclidinium on lung function and symptoms in patients with fixed airflow obstruction and reversibility to salbutamol: A randomised, 3-phase study.

INTRODUCTION: The long-acting muscarinic antagonist, umeclidinium (UMEC), combined with the inhaled corticosteroid, fluticasone furoate (FF), improves lung function in symptomatic patients with asthma. We assessed FF/UMEC in patients with a primary diagnosis of asthma or chronic obstructive pulmonary disease (COPD), but physiological characteristics of both (fixed airflow obstruction and reversibility to salbutamol). METHODS: This double-blind, parallel-arm, 3-phase study randomised 338 patients (1:1:1:1:2:2) to FF 100 mcg alone or combined with UMEC (15.6, 62.5, 125, or 250 mcg) or vilanterol 25 mcg (Phase A, 4 weeks). Primary endpoint: change from baseline in clinic trough forced expiratory volume in 1 s (FEV1) (end of Phase A). Secondary endpoints: morning peak expiratory flow (PEF), rescue medication use and Evaluating Respiratory Symptoms in COPD (E-RS™: COPD) scores. Safety was assessed. RESULTS: In the intent-to-treat population, the increase in trough FEV1 over FF was significant for FF/UMEC 62.5 (0.140 L [p = 0.019]) and 125 mcg (0.120 L [p = 0.039]), with similar changes for patients with a primary diagnosis of asthma or COPD. Changes from baseline in morning PEF and E-RS total score were greater for all FF/UMEC doses vs FF (p ≤ 0.05). Change from baseline in rescue medication use was statistically or clinically significant for all FF/UMEC doses vs FF. The incidence of on-treatment adverse events was 15%-32% (Phase A), with no dose-related effects. CONCLUSIONS: FF/UMEC 62.5 mcg produced clinically meaningful improvements in FEV1, morning PEF, E-RS total score and rescue medication use. FF/UMEC may benefit patients with features of both asthma and COPD. CLINICALTRIALS.GOV: NCT02164539; GSK: 200699.

Drug utilization in the pediatric intensive care unit: monitoring prescribing trends and establishing prioritization of pharmacotherapeutic evaluation of critically ill children.

The primary objective of this study was to characterize the drug exposure for children hospitalized in the authors' institution's pediatric intensive care unit for the year 2002. Secondary objectives included the examination of drug utilization differences among various age criteria and the suitability of the most prevalent resources for pediatric dosing guidance. Many of the most commonly prescribed agents in the pediatric intensive care unit fall into the broad categories of pain management/sedation and anti-infectives. Based on the generally narrow windows afforded by each of these drug classes, it is obvious that more, well-defined investigations in critically ill children are warranted. The existing dosing guidance for many of these agents is neither generalizable nor sufficient to accommodate the diversity in pediatric intensive care unit patients, and the current drug monographs fall short of any practical dosing information.

Pharmacoscintigraphic assessment of the regional drug absorption of the dual angiotensin-converting enzyme/neutral endopeptidase inhibitor, M100240, in healthy volunteers.

M100240 is the thioester of MDL 100,173, a dual angiotensin-converting enzyme (ACE)/neutral endopeptidase (NEP) inhibitor currently in phase II development. The purpose of this study was to evaluate the relative bioavaibility of M100240 in various regions of the gastrointestinal tract using the Enterion capsule, a noninvasive radiocontrolled device providing targeted drug delivery, to explore the absorption characteristics of M100240 in healthy volunteers. In addition, the absolute bioavailability of an immediate-release formulation of M100240 was assessed. Pharmacokinetic data were obtained from 13 healthy subjects in an open-label, single-dose, randomized, five-period crossover study. Treatments included 25 mg M100240 administered via short intravenous infusion, oral immediate-release tablet administration, and oral Enterion capsule delivery of drug substance to the proximal small bowel, distal small bowel, and ascending colon. Each treatment was separated by a 14-day drug-free washout period. The localization of the Enterion capsule in the gastrointestinal tract was monitored using scintigraphic imaging. M100240 and MDL 100,173 plasma concentrations were quantified using a validated LC/MS/MS method, and pharmacokinetic parameters were calculated using noncompartmental methods. The estimates of relative bioavailability in the proximal small bowel, distal small bowel, and ascending colon relative to the oral immediate-release tablet are approximately 94%, 97%, and 41%, respectively. M100240 is primarily absorbed throughout the proximal and distal small bowel with modest absorption in the ascending colon. The absolute bioavailability estimate of the M100240 immediate-release formulation is 49%. These data characterize the fundamental in vivo performance attributes of M100240, thereby providing an approach for optimizing prototype modified-release formulations for this compound.