Pulmonary drug delivery to older people

CBD and THC in Special Populations: Pharmacokinetics and Drug-Drug Interactions

Cannabinoid use has surged in the past decade, with a growing interest in expanding cannabidiol (CBD) and delta-9-tetrahydrocannabinol (THC) applications into special populations. Consequently, the increased use of CBD and THC raises the risk of drug-drug interactions (DDIs). Nevertheless, DDIs for cannabinoids, especially in special populations, remain inadequately investigated. While some clinical trials have explored DDIs between therapeutic drugs like antiepileptic drugs and CBD/THC, more potential interactions remain to be examined. This review summarizes the published studies on CBD and THC-drug interactions, outlines the mechanisms involved, discusses the physiological considerations in pharmacokinetics (PK) and DDI studies in special populations (including pregnant and lactating women, pediatrics, older adults, patients with hepatic or renal impairments, and others), and presents modeling approaches that can describe the DDIs associated with CBD and THC in special populations. The PK of CBD and THC in special populations remain poorly characterized, with limited studies investigating DDIs involving CBD/THC in these populations. Therefore, it is critical to evaluate potential DDIs between CBD/THC and medications that are commonly used in special populations. Modeling approaches can aid in understanding these interactions.

Cost-related medication nonadherence in adults with COPD in the United States 2013-2020

BACKGROUND

Cost-related medication nonadherence (CRN) is associated with poor prognosis among patients with chronic obstructive pulmonary disease (COPD), a population that requires long-term treatment for secondary prevention. In this study, we aimed to estimate the prevalence and sociodemographic characteristics of CRN in individuals with COPD in the US.

METHODS

In a nationally representative survey of US adults in the National Health Interview Survey (2013-2020), we identified individuals aged ≥18 years with a self-reported history of COPD. Cross-sectional study.

RESULTS

Of the 15,928 surveyed individuals, a weighted 18.56% (2.39 million) reported experiencing CRN, including 12.50% (1.61 million) missing doses, 13.30% (1.72 million) taking lower than prescribed doses, and 15.74% (2.03 million) delaying filling prescriptions to save costs. Factors including age < 65 years, female sex, low family income, lack of health insurance, and multimorbidity were associated with CRN.

CONCLUSIONS

In the US, one in six adults with COPD reported CRN. The influencing factors of CRN are multifaceted and necessitating more rigorous research. Targeted interventions based on the identified influencing factors in this study are recommended to enhance medication adherence among COPD patients.

Docetaxel liposomes for lung targeted delivery: development and evaluation

Docetaxel (DTX) is an artificial semi-synthetic second-generation taxane anti-tumor drug, which is suitable for the treatment of various cancers such as lung cancer. The route of administration of DTX formulations has been extended to oral, intravenous, and rectal, with few studies on pulmonary administration being reported. Here, we had developed DTX liposomes (DTX-lips) for pulmonary inhalation administration. The particle size of the preparation was 125 nm, the encapsulation efficiency was 94.4 ± 0.14%, and the drug loading capacity was 1.26 ± 0.01%. It had good stability. The fine particle fraction with aerodynamic diameter less than 6.4 μm accounts for 64.63 ± 0.12%, showed excellent aerosolization performance. DTX-lips were slow to release in simulated lung fluid. The fluorescence distribution experimented in mice and tissues showed that the fluorescence of the inhaled liposome group was mainly distributed in the lung, and the retention time was significantly prolonged as compared with those of the other two groups. No significant fluorescence was observed in other tissues, which was conducive to the full effect of the drug in the lung tissue. DTX-lips had no damage to respiratory system and whole body. These results indicated that the inhaled DTX-lips had good lung targeting, reduced accumulation in other organs, and improved the safety and effectiveness of the drug.

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

INTRODUCTION

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

AREAS COVERED

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

EXPERT OPINION

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

Pharmacotherapies in Older Adults with COPD: Challenges and Opportunities

Older adults have a higher prevalence of chronic obstructive pulmonary disease (COPD), which will likely increase substantially in the coming decades owing to aging populations and increased long-term exposure to risk factors for this disease. COPD in older adults is characterized by low-grade chronic systemic inflammation, known as inflamm-aging. It contributes substantially to age-associated pulmonary changes that are clinically expressed by reduced lung function, poor health status, and limitations in activities of daily living. In addition, inflamm-aging has been associated with the onset of many comorbidities commonly encountered in COPD. Furthermore, physiologic changes that are often seen with aging can influence the optimal treatment of older patients with COPD. Therefore, variables such as pharmacokinetics, pharmacodynamics, polypharmacy, comorbidities, adverse drug responses, drug interactions, method of administration, and social and economic issues that impact nutrition and adherence to therapy must be carefully evaluated when prescribing medication to these patients because each of them alone or together may affect the outcome of treatment. Current COPD medications focus mainly on alleviating COPD-related symptoms, so alternative treatment approaches that target the disease progression are being investigated. Considering the importance of inflamm-aging, new anti-inflammatory molecules are being evaluated, focusing on inhibiting the recruitment and activation of inflammatory cells, blocking mediators of inflammation thought to be important in the recruitment or activation of these inflammatory cells or released by these cells. Potential therapies that may slow the aging processes by acting on cellular senescence, blocking the processes that cause it (senostatics), eliminating senescent cells (senolytics), or targeting the ongoing oxidative stress seen with aging need to be evaluated.

Pharmacokinetics of Antibacterial Agents in the Elderly: The Body of Evidence

Infections are important factors contributing to the morbidity and mortality among elderly patients. High rates of consumption of antimicrobial agents by the elderly may result in increased risk of toxic reactions, deteriorating functions of various organs and systems and leading to the prolongation of hospital stay, admission to the intensive care unit, disability, and lethal outcome. Both safety and efficacy of antibiotics are determined by the values of their plasma concentrations, widely affected by physiologic and pathologic age-related changes specific for the elderly population. Drug absorption, distribution, metabolism, and excretion are altered in different extents depending on functional and morphological changes in the cardiovascular system, gastrointestinal tract, liver, and kidneys. Water and fat content, skeletal muscle mass, nutritional status, use of concomitant drugs are other determinants of pharmacokinetics changes observed in the elderly. The choice of a proper dosing regimen is essential to provide effective and safe antibiotic therapy in terms of attainment of certain pharmacodynamic targets. The objective of this review is to perform a structure of evidence on the age-related changes contributing to the alteration of pharmacokinetic parameters in the elderly.

Pulmonary delivery of resveratrol-β-cyclodextrin inclusion complexes for the prevention of zinc chloride smoke-induced acute lung injury

Smoke bombs are often used in military/fire training, which can produce a large amount of zinc chloride (ZnCl₂) smoke. Inhalation of ZnCl₂ smoke usually causes acute lung injury (ALI) that would likely develop to acute respiratory distress syndrome (ARDS). However, there is no effective prevention or treatment strategy for the smoke-induced ALI. Resveratrol (RES) is a natural polyphenol with good anti-inflammatory and anti-apoptotic activities, but its low solubility, stability, and bioavailability restrict its clinical application. In this study, an inhalable RES formulation composed of RES-β-cyclodextrin inclusion complexes (RES-β-CD) was prepared for the prevention of ZnCl₂ smoke-induced ALI. RES-β-CD powders had a small mass median aerodynamic diameter of 3.61 μm and a high fine particle fraction of 38.84%, suitable for pulmonary inhalation. RES-β-CD exhibited low BEAS-2B cytotoxicity. Pulmonary delivery of RES-β-CD to mice remarkably prevented the smoke-induced ALI with downregulation of TNF-α, IL-1β, STAT3, and GATA3, and upregulation of T-bet and Foxp3. RES-β-CD protected the respiratory function, percutaneous oxygen saturation, physical activity, lung capillary integrity, and lung liquid balance, alleviating inflammation and apoptosis. Pulmonary delivery of the positive drug, budesonide (BUD), also alleviated the smoke-induced ALI by reduction of inflammation and cell apoptosis. RES-β-CD exhibited the regulation of the Th1/Th2 and Treg/Th17 balances, while BUD did not show any effect on immune balances. In conclusion, pulmonary delivery of RES-β-CD is a promising anti-inflammatory and anti-apoptosis strategy for the prevention of ZnCl₂ smoke-induced ALI by direct lung drug distribution and regulation of immune balance.

Low Drug Loading Hampers the Clinical Translation of Peptide Drugs-Containing Metered-Dose Inhalers

Peptide-based drugs have attracted extensive attention from the medical and pharmaceutical industry because of their relatively high safety and efficacy. However, most of the peptide drugs approved are administrated by injection, which can easily cause poor patient compliance. In this circumstance, pulmonary administration as an alternative to injection administration can not only avoid the above issue but also accelerate the absorption rate of peptide drugs and improve bioavailability. Among the pulmonary delivery systems available on the market, metered-dose inhalers (MDIs) have emerged as appealing candidates for pulmonary delivery systems with clinical translational value, owing to their many merits, including portable, easy-to-operate, and cost-effective properties. Nevertheless, the industrialization of peptide drugs-containing MDIs encounters a bottleneck of low drug loading, owing to the incompatibility between the propellant and the peptide drugs, which cannot be effectively overcome by the current carrier particle encapsulation strategy. Herein, we put forward the following strategies: (1) To screen amphiphilic materials with high surface activity and strong interaction with peptide drugs; (2) To construct a chemical connection between peptide drugs and amphiphilic substances; (3) To optimize the cosolvent for dispersing peptide drugs. We suppose these strategies have the potential to defeat the bottleneck problem and provide a new idea for the industrialization of peptide drugs-containing MDIs.

Liposomal remdesivir inhalation solution for targeted lung delivery as a novel therapeutic approach for COVID-19

Strong infectivity enables coronavirus disease 2019 (COVID-19) to rage throughout the world. Moreover, the lack of drugs with definite therapeutic effects further aggravates the spread of the pandemic. Remdesivir is one of the most promising anti-severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) drugs. However, the limited clinical effects make its therapeutic effect controversial, which may result from the poor accumulation and activation of remdesivir in the lung. Therefore, we developed lyophilized remdesivir liposomes (Rdv-lips) which can be reconstituted as liposomal aerosol for pulmonary delivery to improve the in vivo behavior of existing remdesivir cyclodextrin conclusion compound (Rdv-cyc) injections. Liposome encapsulation endowed remdesivir with much higher solubility and better biocompatibility. The in vitro liposomal aerosol characterization demonstrated that Rdv-lips possessed a mass median aerodynamic diameter of 4.118 µm and fine particle fraction (<5 µm) higher than 50%, indicating good pulmonary delivery properties. Compared to the Rdv-cyc intravenous injection group, the Rdv-lips inhalation group displayed a nearly 100-fold increase in the remdesivir-active metabolite nucleotide triphosphate (NTP) concentration and better NTP accumulation in the lung than the Rdv-cyc inhalation group. A faster transition from remdesivir to NTP of Rdv-lips (inhalation) could also be observed due to better cell uptake. Compared to other preparations, the superiority of Rdv-lips was further evidenced by the results of an in vivo safety study, with little possibility of inducing inflammation. In conclusion, Rdv-lips for pulmonary delivery will be a potent formulation to improve the in vivo behavior of remdesivir and exert better therapeutic effects in COVID-19 treatment.

A quantitative approach to predicting lung deposition profiles of pharmaceutical powder aerosols

Dry powder inhalers (DPI) are widely used systems for pulmonary delivery of therapeutics. The inhalation performance of DPIs is influenced by formulation features, inhaler device and inhalation pattern. The current review presents the affecting factors with great focus on powder characteristics which include particle size, shape, surface, density, hygroscopicity and crystallinity. The properties of a formulation are greatly influenced by a number of physicochemical factors of drug and added excipients. Since available particle engineering techniques result in particles with a set of modifications, it is difficult to distinguish the effect of an individual feature on powder deposition behavior. This necessitates developing a predictive model capable of describing all influential factors on dry powder inhaler delivery. Therefore, in the current study, a model was constructed to correlate the inhaler device properties, inhalation flow rate, particle characteristics and drug/excipient physicochemical properties with the resultant fine particle fraction. The r² value of established correlation was 0.74 indicating 86% variability in FPF values is explained by the model with the mean absolute errors of 0.22 for the predicted values. The authors believe that this model is capable of predicting the lung deposition pattern of a formulation with an acceptable precision when the type of inhaler device, inhalation flow rate, physicochemical behavior of active and inactive ingredients and the particle characteristics of DPI formulations are considered.

Design and Assembly of a Thin-Plate Mechatronic Atomizer by 3D Printing

Microfluidic structures and devices have been studied over decades for the transport of liquid through internal channels using versatile microfabrication schemes such as surface and bulk micromachining technologies. One challenge in consideration of the device design involves the breakthrough of microfluidic reservoir and channels being substantially limited in two-dimensional (2D) geometry. However, recent progress of the emerging 3D printing technologies has showed great potential to overcome this problem in a simple manner. This paper comprehensively reports an additive manufacturing of polylactic acid (PLA) layers to significantly improve the complexity in the formation of the 3D microfluidic structures as compared to conventional micro-manufacturing techniques. Moreover, a handheld mechatronic device with a small height of ~10 mm, assembled with a thin planar atomizer and a micro controller, was produced and demonstrated for generation of droplets (~6 μm in diameter). Both the analytical and experimental results indicated that the grids of channel microstructures were simply varied by different line widths (300–500 μm) and spacing (250–400 μm) 3D printed within the device, thereby providing the design capability for capillary flow. In this regard, a variety of complex micro devices fabricated via computer-aided design (CAD) and the 3D printing method could be applied for more applications than ever, such as microfluidic delivery of biomedical materials and health care devices of a small size.

Pharmacology and Therapeutics of Bronchodilators Revisited

Bronchodilators remain the cornerstone of the treatment of airway disorders such as asthma and chronic obstructive pulmonary disease (COPD). There is therefore considerable interest in understanding how to optimize the use of our existing classes of bronchodilator and in identifying novel classes of bronchodilator drugs. However, new classes of bronchodilator have proved challenging to develop because many of these have no better efficacy than existing classes of bronchodilator and often have unacceptable safety profiles. Recent research has shown that optimization of bronchodilation occurs when both arms of the autonomic nervous system are affected through antagonism of muscarinic receptors to reduce the influence of parasympathetic innervation of the lung and through stimulation of β ₂-adrenoceptors (β ₂-ARs) on airway smooth muscle with β ₂-AR-selective agonists to mimic the sympathetic influence on the lung. This is currently achieved by use of fixed-dose combinations of inhaled long-acting β ₂-adrenoceptor agonists (LABAs) and long-acting muscarinic acetylcholine receptor antagonists (LAMAs). Due to the distinct mechanisms of action of LAMAs and LABAs, the additive/synergistic effects of using these drug classes together has been extensively investigated. More recently, so-called "triple inhalers" containing fixed-dose combinations of both classes of bronchodilator (dual bronchodilation) and an inhaled corticosteroid in the same inhaler have been developed. Furthermore, a number of so-called "bifunctional drugs" having two different primary pharmacological actions in the same molecule are under development. This review discusses recent advancements in knowledge on bronchodilators and bifunctional drugs for the treatment of asthma and COPD. SIGNIFICANCE STATEMENT: Since our last review in 2012, there has been considerable research to identify novel classes of bronchodilator drugs, to further understand how to optimize the use of the existing classes of bronchodilator, and to better understand the role of bifunctional drugs in the treatment of asthma and chronic obstructive pulmonary disease.

Inhalation therapy devices for the treatment of obstructive lung diseases: the history of inhalers towards the ideal inhaler

Inhalation therapy allows conveying drugs directly into the airways. The devices used to administer inhaled drugs play a crucial role in the management of obstructive lung diseases such as asthma and chronic obstructive pulmonary disease (COPD). To ensure high bronchial deposition of the drug, a device should deliver a high proportion of fine particles, be easy to use, and provide constant and accurate doses of the active substance. Nowadays, four different types of inhalers are widely used: nebulizers, dry powder inhalers (DPIs), pressurized metered-dose inhalers (pMDIs), and soft mist inhalers (SMIs). Nebulizers can be used by patients unable to use other inhalers. However, they require long times of administration and do not ensure precise dosages. The first pMDIs became popular since they were small, inexpensive, fast, and silent. Their performance was improved by spacers and then by new technologies which reduced the delivery speed. In DPIs, micronized drug particles are attached to larger lactose carrier particles. No coordination between actuation and inhalation is required. However, the patient is supposed to produce an adequate inspiratory flow to extract the drug and disaggregate it from the carrier. In SMIs, the medication is dissolved in an aqueous solution, without propellant, and it is dispensed as a slow aerosol cloud thanks to the energy of a spring. Smart inhalers, connected to smartphones, are promising tools that can provide information about patient's adherence and their inhaler technique. Inhalation has also been proposed as a route of administration for several systemic drugs.

Inhalation Technique Errors with Metered-Dose Inhalers Among Patients with Obstructive Lung Diseases: A Systematic Review and Meta-Analysis of U.S. Studies

Background

Metered dose inhalers (MDIs) are commonly prescribed for inhalation therapy, but correct use is critical to promoting effective medication delivery. This systematic literature review and meta-analysis evaluates the overall and step-by-step prevalence of errors among adults with obstructive lung diseases in the United States who used MDIs.

Methods

Electronic and manual searches conducted between 1979-2018 using PubMed, EMBASE, PsycINFO, Cochrane, and Google identified 10 articles that met the following inclusion criteria: (a) English language, (b) U.S. adults diagnosed with chronic obstructive pulmonary disease, and (c) MDI use error rates. Meta-analytic techniques using random-effects models were applied to calculate effect sizes, weighted proportions, and 95% confidence intervals (CIs). Heterogeneity was assessed by the I² statistic.

Results

Aggregate findings revealed that 86.7% of patients (n=390, 95% CI 77.5-96.0) made at least 1 inhalation technique error, and 76.9% (n=885, 95% CI 65.8-87.9) incorrectly performed ≥ 20% of device use steps. The most prevalent step-by-step errors across the studies (n=1105) were failure to: (a) exhale fully and away from the inhaler before inhalation (65.5% [95% CI 52.0, 78.9]); (b) hold breath for 5-10 seconds (41.9% [95% CI 29.8, 53.9]); (c) inhale slowly and deeply (39.4% [95% CI 26.2, 52.5]); (d) exhale after inhalation (35.9% [95% CI 17.0, 54.8]); and (e) shake the inhaler before use (34.2% [95% CI 30.6, 37.7]).

Conclusions

Across the studies used in this meta-analysis more than three-fourths of U.S. adults with obstructive lung diseases used MDIs incorrectly. Our findings suggest the need for ongoing patient education and consideration of alternative devices to mitigate errors.

Pharmacists' training to improve inhaler technique of patients with COPD in Vietnam

Background

Incorrect use of inhalers is very common and subsequently leads to poor control of COPD. Among health care providers, pharmacists are in the best position to educate patients about the correct use of inhaler devices.

Objective

The objective of this study was to evaluate the impact of pharmacist-led training on the improvement of inhaler technique for COPD patients in Vietnam.

Patients and methods

For this pre- and post-intervention study, standardized checklists of correct use of metered-dose inhalers (MDIs) and dry powder inhalers (DPIs) were used to evaluate the inhaler technique. A scoring system (maximum score =8) was applied before and after training to guarantee assessment uniformity among pharmacists. Three methods including "face-to-face training", "teach-back" and "technique reminder label" were used. After the baseline evaluation (T0), the inhaler technique was reassessed after 1 month (T1), 3 months (T2), 6 months (T3) and 12 months (T4).

Results

A total of 211 COPD patients participated in the study. Before the training, a high rate of errors was recorded. After the training, the percentage of patients using MDIs and DPIs perfectly increased significantly (p<0.05). The mean technique score for MDIs and DPIs improved from 6.0 (T0) to 7.5 (T3) and 6.9 (T4) and 6.7 (T0) to 7.6 (T3) and 7.2 (T4), respectively (p<0.05). The average training time was 6 minutes (T0) and 3 minutes (T3), respectively.

Conclusion

Pharmacist-led comprehensive inhaler technique intervention program using an unbiased and simple scoring system can significantly improve the inhaler techniques in COPD patients. Our results indicated a 3-month period as the optimal time period between training and retraining for maintaining the correct inhaler technique. The training would be highly feasible and suitable for implementing in the clinical setting. Our model of pharmacist-led training should be considered as an effective solution for managing COPD patients and better utilization of health care human resources, especially in a developing country like Vietnam.