Assessment of the predictive capability of modelling and simulation to determine bioequivalence of inhaled drugs: A systematic review.

OBJECTIVES: There are a multitude of different modelling techniques that have been used for inhaled drugs. The main objective of this review was to conduct an exhaustive survey of published mathematical models in the area of asthma and chronic obstructive pulmonary disease (COPD) for inhalation drugs. Additionally, this review will attempt to assess the applicability of these models to assess bioequivalence (BE) of orally inhaled products (OIPs). EVIDENCE ACQUISITION: PubMed, Science Direct, Web of Science, and Scopus databases were searched from 1996 to 2020, to find studies that described mathematical models used for inhaled drugs in asthma/COPD. RESULTS: 50 articles were finally included in this systematic review. This research identified 22 articles on in silico aerosol deposition models, 20 articles related to population pharmacokinetics and 8 articles on physiologically based pharmacokinetic modelling (PBPK) modelling for inhaled drugs in asthma/COPD. Among all the aerosol deposition models, computational fluid dynamics (CFD) simulations are more likely to predict regional aerosol deposition pattern in human respiratory tracts. Across the population PK articles, body weight, gender, age and smoking status were the most common covariates that were found to be significant. Further, limited published PBPK models reported approximately 29 parameters relevant for absorption and distribution of inhaled drugs. The strengths and weaknesses of each modelling technique has also been reviewed. CONCLUSION: Overall, while there are different modelling techniques that have been used for inhaled drugs in asthma and COPD, there is very limited application of these models for assessment of bioequivalence of OIPs. This review also provides a ready reference of various parameters that have been considered in various models which will aid in evaluation if one model or hybrid in silico models need to be considered when assessing bioequivalence of OIPs.

Disruptions in oral and nasal microbiota in biomass and tobacco smoke associated chronic obstructive pulmonary disease.

Chronic exposures to tobacco and biomass smoke are the most prevalent risk factors for COPD development. Although microbial diversity in tobacco smoke-associated COPD (TSCOPD) has been investigated, microbiota in biomass smoke-associated COPD (BMSCOPD) is still unexplored. We aimed to compare the nasal and oral microbiota between healthy, TSCOPD, and BMSCOPD subjects from a rural population in India. Nasal swabs and oral washings were collected from healthy (n = 10), TSCOPD (n = 11), and BMSCOPD (n = 10) subjects. The downstream analysis was performed using QIIME pipeline (v1.9). In nasal and oral microbiota no overall differences were noted, but there were key taxa that had differential abundance in either Healthy vs COPD and/or TSCOPD vs. BMSCOPD. Genera such as Actinomyces, Actinobacillus, Megasphaera, Selenomonas, and Corynebacterium were significantly higher in COPD subjects. This study suggests that microbial community undergoes dysbiosis which may further contribute to the progression of disease. Thus, it is important to identify etiological agents for such a polymicrobial alterations which contribute highly to the disease manifestation.

Phenotypic comparison between smoking and non-smoking chronic obstructive pulmonary disease.

BACKGROUND: Although COPD among non-smokers (NS-COPD) is common, little is known about this phenotype. We compared NS-COPD subjects with smoking COPD (S-COPD) patients in a rural Indian population using a variety of clinical, physiological, radiological, sputum cellular and blood biomarkers. METHODS: Two hundred ninety subjects (118 healthy, 79 S-COPD, 93 NS-COPD) performed pre- and post-bronchodilator spirometry and were followed for 2 years to study the annual rate of decline in lung function. Body plethysmography, impulse oscillometry, inspiratory-expiratory HRCT, induced sputum cellular profile and blood biomarkers were compared between 49 healthy, 45 S-COPD and 55 NS-COPD subjects using standardized methods. Spirometric response to oral corticosteroids was measured in 30 female NS-COPD patients. RESULTS: Compared to all male S-COPD subjects, 47% of NS-COPD subjects were female, were younger by 3.2 years, had greater body mass index, a slower rate of decline in lung function (80 vs 130 mL/year), more small airways obstruction measured by impulse oscillometry (p < 0.001), significantly less emphysema (29% vs 11%) on CT scans, lower values in lung diffusion parameters, significantly less neutrophils in induced sputum (p < 0.05) and tended to have more sputum eosinophils. Hemoglobin and red cell volume were higher and serum insulin lower in S-COPD compared to NS-COPD. Spirometric indices, symptoms and quality of life were similar between S-COPD and NS-COPD. There was no improvement in spirometry in NS-COPD patients after 2 weeks of an oral corticosteroid. CONCLUSIONS: Compared to S-COPD, NS-COPD is seen in younger subjects with equal male-female predominance, is predominantly a small-airway disease phenotype with less emphysema, preserved lung diffusion and a slower rate of decline in lung function.

Bacterial load and defective monocyte-derived macrophage bacterial phagocytosis in biomass smoke-related COPD.

Lower airway colonisation with species of potentially pathogenic bacteria (PPB) is associated with defective bacterial phagocytosis, in monocyte-derived macrophages (MDMs) and alveolar macrophages, from tobacco smoke-associated chronic obstructive pulmonary disease (S-COPD) subjects. In the developing world, COPD among nonsmokers is largely due to biomass smoke (BMS) exposure; however, little is known about PPB colonisation and its association with impaired innate immunity in these subjects.We investigated the PPB load (Streptococcus pneumoniae, Haemophilus influenzae, Moraxella catarrhalis and Pseudomonas aeruginosa) in BMS-exposed COPD (BMS-COPD) subjects compared with S-COPD and spirometrically normal subjects. We also examined the association between PPB load and phagocytic activity of MDMs and lung function. Induced sputum and peripheral venous blood samples were collected from 18 healthy nonsmokers, 15 smokers without COPD, 16 BMS-exposed healthy subjects, 19 S-COPD subjects and 23 BMS-COPD subjects. PPB load in induced sputum and MDM phagocytic activity were determined using quantitative PCR and fluorimetry, respectively.Higher bacterial loads of S. pneumoniae, H. influenzae and P. aeruginosa were observed in BMS-COPD subjects. Increased PPB load in BMS-exposed subjects was significantly negatively associated with defective phagocytosis in MDMs and spirometric lung function indices (p<0.05).Increased PPB load in airways of BMS-COPD subjects is inversely associated with defective bacterial phagocytosis and lung function.

Association between the Serum Metabolic Profile and Lung Function in Chronic Obstructive Pulmonary Disease.

OBJECTIVES: Although dietary patterns are known to modulate disease severity in patients with chronic obstructive pulmonary disease (COPD), the relationship between the circulating lipid profile and lung function in COPD has not been studied extensively. MATERIAL AND METHODS: There were 43 COPD patients with a history of smoking and 39 patients with a history of biomass fuel exposure recruited in this study, along with 43 age-matched healthy controls. All participants underwent complete lung function profiling, and their glucose and lipid profiles were measured. The association between the metabolic profile and lung function was assessed using the Spearman's rank-order correlation coefficient. RESULTS: 52.4% of the COPD patients were smokers compared to the healthy group (46.5%). We found an inverse correlation between triglyceride and functional residual capacity (p=-0.21, p=0.05) and a positive association between serum cholesterol and overall airway resistance (R5) (p=0.24, p=0.04) and central airway resistance (R20) (p=0.32, p=0.004). Low-density lipoprotein (LDL) cholesterol and high-density lipoprotein (HDL) ratio and LDL/HDL ratio were also found to correlate with R5 (p=0.25, 0.23, and 0.22, respectively) and R20 (p=0.31, 0.24, and 0.24, respectively). No significant association was observed between other metabolites and either spirometric or plethysmographic lung function indices. CONCLUSION: High serum triglyceride and cholesterol may increase the resistance in the airways, which may lead to increased airway obstruction. Therefore, monitoring of lipid profile should be considered in the diagnosis and management of COPD.

A cross-sectional study on prevalence of chronic obstructive pulmonary disease (COPD) in India: rationale and methods.

BACKGROUND: Chronic obstructive pulmonary disease (COPD) is a common preventable and treatable chronic respiratory disease, which affects 210 million people globally. Global and national guidelines exist for the management of COPD. Although evidence-based, they are inadequate to address the phenotypic and genotypic heterogeneity in India. Co-existence of other chronic respiratory diseases can adversely influence the prognosis of COPD.India has a huge burden of COPD with various risk factors and comorbid conditions. However, valid prevalence estimates employing spirometry as the diagnostic tool and data on important comorbid conditions are not available. This study protocol is designed to address this knowledge gap and eventually to build a database to undertake long-term cohort studies to describe the phenotypic and genotypic heterogeneity among COPD patients in India. OBJECTIVES: The primary objective is to estimate the prevalence of COPD among adults aged ≥25 years for each gender in India. The secondary objective is to identify the risk factors for COPD and important comorbid conditions such as asthma and post-tuberculosis sequelae. It is also proposed to validate the currently available definitions for COPD diagnosis in India. METHODS AND ANALYSIS: A cross-sectional study will be undertaken among the populations of sub-urban areas of Chennai and Shillong cities, which represent the Southern and Northeastern regions of India. We will collect data on sociodemographic variables, economic characteristics, risk factors of COPD and comorbidities. The Global Initiative for Obstructive Lung Disease (GOLD) and Global Initiative for Asthma (GINA) definitions will be used for the diagnosis of COPD and asthma. Data will be analysed for estimation of the prevalence of COPD, asthma and associated factors. ETHICS AND DISSEMINATION: This study proposal was approved by the respective institutional ethics committees of participating institutions. The results will be disseminated through publications in the peer-reviewed journals and a report will be submitted to the concerned public health authorities in India for developing appropriate research and management policies.

Measuring lung function using sound waves: role of the forced oscillation technique and impulse oscillometry system.

Measuring lung function is an important component in the decision making process for patients with obstructive airways disease (OAD). Not only does it help in arriving at a specific diagnosis, but it also helps in evaluating severity so that appropriate pharmacotherapy can be instituted, it helps determine prognosis and it helps evaluate response to therapy. Spirometry is currently the most commonly performed lung function test in clinical practice and is considered to be the gold standard diagnostic test for asthma and COPD. However, spirometry is not an easy test to perform because the forceful expiratory and inspiratory manoeuvres require good patient co-operation. Children aged <5 years, elderly people and those with physical and cognitive limitations cannot perform spirometry easily.

Aclidinium bromide/formoterol fixed-dose combination therapy for COPD: the evidence to date.

The quest for the right combination of bronchodilators with different mechanisms of action such as long-acting muscarinic antagonists and long-acting ß-agonists in the management of stable moderate-to-severe chronic obstructive pulmonary disease (COPD) is a topic of intense research activity currently, given the rising morbidity and mortality due to this disease. The fixed-dose combination of aclidinium bromide and formoterol fumarate in a single inhaler seems to offer superior advantages over either drugs given alone or as separate inhalers concurrently. Since the fixed-dose combination needs to be given twice daily, it is likely to achieve control of symptoms most crucial to the quality of life in COPD, namely, the morning hours. This is reflected in significant trough FEV1 (forced expiratory volume in 1 second) improvements after the dose. This paper reviews the various studies related to this combination put in the perspective of its safety and efficacy and potential benefits over other therapeutic options. However, there is a dearth of data on the long-term safety and efficacy in terms of improvement in lung function. This combination could emerge as an excellent option in the management of stable COPD if data on exacerbation rates and patient-reported outcomes become available from longer-term studies. Moreover, we need some more studies to define the ideal phenotype of COPD best suited for the use of this combination.

Occupational cadmium exposure-associated oxidative stress and erythrocyte fragility among jewelry workers in India.

BACKGROUND: Cadmium-induced pulmonary and renal target organ effects are well-established although its association with oxidative stress and associated hematological effects for human toxicity remain understudied. METHODS: In a population of cadmium-exposed male jewelry manufacturing workers (n = 32) and referents without direct exposure (n = 21), all with urinary cadmium quantification, we measured plasma antioxidant enzymes (catalase, superoxide dismutase), lipid peroxidation (malondialdehyde), erythrocyte fragility, and surface irregularity of the erythrocyte membrane. RESULTS: Compared to referents, exposed workers manifested significantly lower plasma antioxidant enzymes, and increased malondialdehyde and erythrocyte fragility (for all, P < 0.01). Consistent with the exposure subcategories, activities of superoxide dismutase and catalase were reduced and lipid peroxidation and erythrocyte fragility were enhanced (P < 0.01 for all) in terms of Cd-effect indicating a strong impact on hematological system and oxidative stress. CONCLUSION: Cd exposure contributes to oxidative stress and related erythrocyte effects thus making the hematological system another end-organ target for chronic Cd toxicity.

Profiles of chronic obstructive lung disease: characteristics of stable chronic obstructive lung disease in different parts of Asia.

PURPOSE OF REVIEW: This review discusses the recent Asian chronic obstructive lung disease (COPD) studies that characterize stable COPD, to understand its peculiarities. RECENT FINDINGS: Asian research has improved our understanding of COPD. Household air pollution (HAP) is as important as smoking. Smoking in Asia is varied, and noncigarette smoking exposure remains under-investigated. Prevalence studies are often questionnaire based. Spirometry-based prevalence needs study. Burden of obstructive lung disease studies are getting published. Female COPD in Asia is predominantly HAP induced. The patients are underweight, milder 'Global Initiative for Obstructive Lung Disease- class' and have compromised health-related quality of life often with depression and anxiety, but other comorbidities do occur and are getting defined.Nonsmokers' COPD is often associated with small airway thickening, less emphysema, but considerable morbidity. Asian COPD may have an eosinophilic component, but its significance is unknown. There is genetic predisposition among some Asians to COPD, and among some patients to lung cancer. The emerging pandemic of lifestyle diseases demands that metabolic and cardiovascular comorbidities in COPD need investigation. SUMMARY: COPD in Asia is increasing and burdensome. It is affecting both sexes; is caused by HAP as much as smoking; causes poor quality of life and intense psychological burden; and is associated with unique patho-physiology, which will require research and action.

Priming of beta-2 agonist and antimuscarinic induced physiological responses induced by 1200mg/day NAC in moderate to severe COPD patients: A pilot study.

UNLABELLED: This study evaluated antioxidant modulations of lung physiological-responses to beta-2-agonist and antimuscarinic bronchodilators with 1200mg/day n-acetyl-cysteine (NAC) in a placebo-controlled, randomised, double-blind, parallel-group study, in moderate-very severe COPD patients. METHODS: 15 COPD patients received NAC treatment, while 9 COPD patients received placebo treatment, for 15 days. Pre-and-post salbutamol and ipratopium-bromide lung-physiology responses were measured using body-plethysmography, impulse-oscillometry (IOS) and spirometry before-and-after study treatments. RESULTS: Compared to pre-treatment, the NAC-treatment significantly enhanced the potential of ipratopium-bromide to reduce functional-residual-capacity (FRC) by nearly 3-folds (mean% FRC-response: pre-NAC: -5.51%±10.42% versus post-NAC: -17.89%±12.94%, p=0.02; mean-absolute FRC-response: pre-NAC: -300ml±450ml versus post-NAC: -770ml±550ml, p=0.02), which was superior to placebo-treatment. The increase in total-lung-capacity response to ipratopium-bromide, although insignificant, was superior with post-NAC treatment versus post-placebo treatment (p=0.049). The salbutamol-response remained unaltered with either treatment. CONCLUSION: The treatment with 1200mg/day NAC has potential to enhance the bronchodilator ability of antimuscarinic-agents but not beta-2-agonist. However, its clinical application has to be established in large sample-size studies for longer-duration.

Bronchodilator efficacy of tiotropium-formoterol via single pressurized meter dose inhaler (pMDI) versus tiotropium alone in COPD.

BACKGROUND: Bronchodilators form the main stay of treatment for COPD. When symptoms are not adequately controlled with one bronchodilator, addition of another bronchodilator is recommended. We have recently developed a combination of tiotropium and formoterol in a single pressurized metered dose inhaler (pMDI) (Cipla Ltd., India). The aim of this study was to compare the bronchodilator effects of a single dose of 18 mcg of tiotropium versus a single dose of a combination of 18 mcg tiotropium plus 12 mcg formoterol administered via a pMDI in subjects with moderate-to-severe COPD. STUDY DESIGN: 44 COPD subjects were enrolled in this randomized, double-blind, multi-centre, cross-over study. 18 mcg tiotropium and 18 mcg tiotropium plus 12 mcg formoterol were administered via pressurized metered dose inhalers on two separate days. FEV(1), FVC and Inspiratory capacity (IC) were measured before, 15, 30 min, 1, 2, 3, 4, 6, 8, 12 and 24 h after the study drugs were administered. RESULTS: Compared with tiotropium alone, a combination of tiotropium plus formoterol showed a faster onset of bronchodilator response (p < 0.01 for FEV(1) and FVC), a greater mean maximum change in FEV(1) (p = 0.01) and FVC (p = 0.008) and greater AUC(0-24h) values for FEV(1), FVC and IC. Trough FEV(1) and FVC values were also greater in the combination group. CONCLUSION: A combination of tiotropium plus formoterol administered via a single inhaler produced a superior bronchodilator response than tiotropium alone over a period of 24 h.

Obesity and asthma: physiological perspective.

Obesity induces some pertinent physiological changes which are conducive to either development of asthma or cause of poorly controlled asthma state. Obesity related mechanical stress forces induced by abdominal and thoracic fat generate stiffening of the lungs and diaphragmatic movements to result in reduction of resting lung volumes such as functional residual capacity (FRC). Reduced FRC is primarily an outcome of decreased expiratory reserve volume, which pushes the tidal breathing more towards smaller high resistance airways, and consequentially results in expiratory flow limitation during normal breathing in obesity. Reduced FRC also induces plastic alteration in the small collapsible airways, which may generate smooth muscle contraction resulting in increased small airway resistance, which, however, is not picked up by spirometric lung volumes. There is also a possibility that chronically reduced FRC may generate permanent adaptation in the very small airways; therefore, the airway calibres may not change despite weight reduction. Obesity may also induce bronchodilator reversibility and diurnal lung functional variability. Obesity is also associated with airway hyperresponsiveness; however, the mechanism of this is not clear. Thus, obesity has effects on lung function that can generate respiratory distress similar to asthma and may also exaggerate the effects of preexisting asthma.