Advances in device and formulation technologies for pulmonary drug delivery

Nano vs Resistant Tuberculosis: Taking the Lung Route

Tuberculosis (TB) is among the top 10 infectious diseases worldwide. It is categorized among the leading killer diseases that are the reason for the death of millions of people globally. Although a standardized treatment regimen is available, non-adherence to treatment has increased multi-drug resistance (MDR) and extensive drug-resistant (XDR) TB development. Another challenge is targeting the death of TB reservoirs in the alveoli via conventional treatment. TB Drug resistance may emerge as a futuristic restraint of TB with the scarcity of effective Anti-tubercular drugs. The paradigm change towards nano-targeted drug delivery systems is mostly due to the absence of effective therapy and increased TB infection recurrent episodes with MDR. The emerging field of nanotechnology gave an admirable opportunity to combat MDR and XDR via accurate diagnosis with effective treatment. The new strategies targeting the lung via the pulmonary route may overcome the new incidence of MDR and enhance patient compliance. Therefore, this review highlights the importance and recent research on pulmonary drug delivery with nanotechnology along with prevalence, the need for the development of nanotechnology, beneficial aspects of nanomedicine, safety concerns of nanocarriers, and clinical studies.

Review of inhalable nanoparticles for the pulmonary delivery of anti-tuberculosis drugs

Tuberculosis is an airborne disease caused by the pathogen, Mycobacterium tuberculosis, which predominantly affects the lungs. World Health Organization (WHO) has reported that about 85% of TB patients are cured with the existing 6-month antibiotic regimen. However, the lengthy oral administration of high-dose anti-TB drugs is associated with significant side effects and leads to drug resistance cases. Alternatively, reformulating existing anti-tubercular drugs into inhalable nanoparticulate systems is a promising strategy to overcome the challenges associated with oral treatment as they could enhance drug retention in the pulmonary region to achieve an optimal drug concentration in the infected lungs. Hence, this review provides an overview of the literature on inhalable nano-formulations for the delivery of anti-TB drugs, including their formulation techniques and preclinical evaluations between the years 2000 and 2020, gathered from electronic journals via online search engines such as Google Scholar and PubMed. Previous in vitro and in vivo studies highlighted that the nano-size, low toxicity, and high efficacy were among the factors influencing the fate of nanoparticulate system upon deposition in the lungs. Although many preclinical studies have shown that inhalable nanoparticles increased therapeutic efficacy and minimised adverse drug reactions when delivered through the pulmonary route, none of them has progressed into clinical trials to date. This could be attributed to the high cost of inhaled regimes due to the expensive production and characterisation of the nanoparticles as well as the need for an inhalation device as compared to the oral treatment. Another barrier could be the lack of medical acceptance due to insufficient number of trained staff to educate the patients on the correct usage of the inhalation device. Hence, these barriers should be addressed satisfactorily to make the inhaled nanoparticles regimen a reality for the treatment of TB.

Inhalation Dosage Forms: A Focus on Dry Powder Inhalers and Their Advancements

In this review, an extensive analysis of dry powder inhalers (DPIs) is offered, focusing on their characteristics, formulation, stability, and manufacturing. The advantages of pulmonary delivery were investigated, as well as the significance of the particle size in drug deposition. The preparation of DPI formulations was also comprehensively explored, including physico-chemical characterization of powders, powder processing techniques, and formulation considerations. In addition to manufacturing procedures, testing methods were also discussed, providing insights into the development and evaluation of DPI formulations. This review also explores the design basics and critical attributes specific to DPIs, highlighting the significance of their optimization to achieve an effective inhalation therapy. Additionally, the morphology and stability of 3 DPI capsules (Spiriva, Braltus, and Onbrez) were investigated, offering valuable insights into the properties of these formulations. Altogether, these findings contribute to a deeper understanding of DPIs and their development, performance, and optimization of inhalation dosage forms.

Novel Vectors and Administrations for mRNA Delivery

mRNA therapy has shown great potential in infectious disease vaccines, cancer immunotherapy, protein replacement therapy, gene editing, and other fields due to its central role in all life processes. However, mRNA is challenging to pass through the cell membrane due to its significant negative charges and degradation from RNase, so the key to mRNA therapy is efficient packaging and delivery of it with appropriate vectors. Presently researchers have developed various vectors such as viruses and liposomes, but these conventional vectors are now difficult to meet the growing requirement like safety, efficiency, and targeting, so many novel delivery vectors with unique advantages have emerged recently. This review mainly introduces two categories of novel vectors: biomacromolecules and inorganic nanoparticles, as well as two novel methods of control and administration based on these novel vectors: controlled-release administration and non-invasive administration. These novel delivery strategies have the advantages of high safety, biocompatibility, versatility, intelligence, and targeting. This paper analyzes the challenges faced by the field of mRNA delivery in depth, and discusses how to use the characteristics of novel vectors and administrations to solve these problems.

Effect of laryngeal jet on dry powder inhaler aerosol deposition: a numerical simulation

Although pulmonary drug delivery has been deeply investigated, the effect of the laryngeal jet on particle deposition during drug delivery with dry powder inhalers (DPI) has not been evaluated profoundly. In this study, the flow structure and particle deposition pattern of a DPI in two airway models, one with mouth-throat region including the larynx and the other one without it, are numerically investigated. The results revealed that the laryngeal jet has a considerable effect on particle deposition. The presence of laryngeal jet leads to 4-fold and 2-fold higher deposition efficiencies for inlet flow rates of 30 and 90 L/min, respectively.

Modulation of engineered nanomaterial interactions with organ barriers for enhanced drug transport

The biomedical use of nanoparticles (NPs) has been the focus of intense research for over a decade. As most NPs are explored as carriers to alter the biodistribution, pharmacokinetics and bioavailability of associated drugs, the delivery of these NPs to the tissues of interest remains an important topic. To date, the majority of NP delivery studies have used tumor models as their tool of interest, and the limitations concerning tumor targeting of systemically administered NPs have been well studied. In recent years, the focus has also shifted to other organs, each presenting their own unique delivery challenges to overcome. In this review, we discuss the recent advances in leveraging NPs to overcome four major biological barriers including the lung mucus, the gastrointestinal mucus, the placental barrier, and the blood-brain barrier. We define the specific properties of these biological barriers, discuss the challenges related to NP transport across them, and provide an overview of recent advances in the field. We discuss the strengths and shortcomings of different strategies to facilitate NP transport across the barriers and highlight some key findings that can stimulate further advances in this field.

Inhaled lipid nanocarriers for pulmonary delivery of glucocorticoids: previous strategies, recent advances and key factors description

In view of the strong anti-inflammatory activity of glucocorticoids (GC) they are used in the treatment of almost all inflammatory lung diseases. In particular, inhaled GC (IGC) allow high drug concentrations to be deposited in the lung and may reduce the incidence of adverse effects associated with systemic administration. However, rapid absorption through the highly absorbent surface of the lung epithelium may limit the success of localized therapy. Therefore, inhalation of GC incorporated into nanocarriers is a possible approach to overcome this drawback. In particular, lipid nanocarriers, which showed high pulmonary biocompatibility and are well known in the pharmaceutical industry, have the best prospects for pulmonary delivery of GC by inhalation. This review provides an overview of the pre-clinical applications of inhaled GC-lipid nanocarriers based on several key factors that will determine the efficiency of local pulmonary GC delivery: 1) stability to nebulization, 2) deposition profile in the lungs, 3) mucociliary clearance, 4) selective accumulation in target cells, 5) residence time in the lung and systemic absorption and 6) biocompatibility. Finally, novel preclinical pulmonary models for inflammatory lung diseases are also discussed.

Amorphous Drug Nanoparticles for Inhalation Therapy of Multidrug-Resistant Tuberculosis

Tuberculosis (TB) is one of the most prevalent infectious diseases. The global TB situation is further complicated by increasing patient numbers infected with Mycobacterium tuberculosis (M.tb.) strains resistant to either one or two of the first-line therapeutics, promoted by insufficient treatment length and/or drug levels due to adverse reactions and reduced patient compliance. An intriguing approach to improve anti-TB therapy relates to nanocarrier-based drug-delivery systems, which enhance local drug concentrations at infection sites without systemic toxicity. Recently developed anti-TB antibiotics, however, are lipophilic and difficult to transport in aqueous systems. Here, the very lipophilic TB-antibiotics bedaquiline (BDQ) and BTZ (1,3-benzothiazin-4-one 043) are prepared as high-dose, amorphous nanoparticles via a solvent-antisolvent technique. The nanoparticles exhibit mean diameters of 60 ± 13 nm (BDQ) and 62 ± 44 nm (BTZ) and have an extraordinarily high drug load with 69% BDQ and >99% BTZ of total nanoparticle mass plus a certain amount of surfactant (31% for BDQ, <1% for BTZ) to make the lipophilic drugs water-dispersible. Suspensions with high drug load (4.1 mg/mL BDQ, 4.2 mg/mL BTZ) are stable for several weeks. In vitro and in vivo studies employing M.tb.-infected macrophages and susceptible C3HeB/FeJ mice show promising activity, which outperforms conventional BDQ/BTZ solutions (in DMF or DMSO) with an up to 50% higher efficacy upon pulmonary delivery. In vitro, the BDQ/BTZ nanoparticles demonstrate their ability to cross the different biological barriers and to reach the site of the intracellular mycobacteria. In vivo, high amounts of the BDQ/BTZ nanoparticles are found in the lung and specifically inside granulomas, whereas only low BDQ/BTZ-nanoparticle levels are observed in spleen or liver. Thus, pulmonary delivered BDQ/BTZ nanoparticles are promising formulations to improve antituberculosis treatment.

Amikacin@SiO2 core@shell nanocarriers to treat pulmonal bacterial infections

AMC@SiO₂ core@shell nanocarriers (AMC: amikacin) are realized and contain an exceptionally high drug load of 0.8 mg mg^-1 (i.e. 80% AMC of total nanocarrier mass). They are prepared via a solvent-antisolvent approach with AMC nanoparticles formed in a first step, which are then covered and stabilised by a thin silica shell in a one-pot synthesis. In total, the core@shell nanocarriers exhibit a mean diameter of 240 nm with an inner AMC core of 200 nm and an outer silica shell of 20 nm. Subsequent to synthesis, the nanocarriers can be stored in frozen dimethylsulfoxide (DMSO) and applied directly after warming to room temperature with particle contents of 5 mg mL^-1. Size, structure, and composition of the AMC@SiO₂ core@shell nanocarriers are evidenced by electron microscopy (SEM, TEM), spectroscopic methods (EDXS, FT-IR, UV-Vis), as well as X-ray powder diffraction and elemental analysis. As proof-of-concept, the AMC release and the activity of the novel nanocarriers are tested against two relevant, difficult-to-treat and notoriously multidrug resistant, bacterial pathogens: Mycobacterium tuberculosis (M.tb.) and Mycobacterium abscessus (M.abs.). Colloidal stability, storage stability, high drug load, and activity of the AMC@SiO₂ core@shell nanocarriers are promising for, e.g., aerosol-type pulmonal application.

Feedback systems in multi-dose dry powder inhalers

Dry powder inhalers (DPIs) are a large, highly diverse group of inhalation devices. DPIs differentiate the process of measuring the dose of the drug and preparing the inhaler for use, but also the way of transmitting and the scope of feedback on the inhalation process that the user receives. The functioning of simple and technologically advanced systems of feedback on the inhalation process in the most commonly used multi-dose DPIs is discussed. All these DPIs have a dose counter. Only three DPIs - Novolizer^®, Genuair^® and NEXThaler^® provide feedback to the patient in the form of auditory and visual signals confirming the correctness of the inhalation performed. This is important for the correct use of the inhaler, and thus for obtaining the expected therapeutic effects.

Tadalafil Nanoemulsion Mists for Treatment of Pediatric Pulmonary Hypertension via Nebulization

Oral tadalafil (TD) proved promising in treating pediatric pulmonary arterial hypertension (PAH). However, to ensure higher efficacy and reduce the systemic side effects, targeted delivery to the lungs through nebulization was proposed as an alternative approach. This poorly soluble drug was previously dissolved in nanoemulsions (NEs). However, the formulations could not resist aqueous dilution, which precluded its dilution with saline for nebulization. Thus, the current study aimed to modify the previous systems into dilutable TD-NEs and assess their suitability for a pulmonary application. In this regard, screening of various excipients was conducted to optimize the former systems; different formulations were selected and characterized in terms of physicochemical properties, nebulization performance, stability following sterilization, and biocompatibility. Results showed that the optimal system comprised of Capmul-MCM-EP:Labrafac-lipophile (1:1) (w/w) as oil, Labrasol:Poloxamer-407 (2:1) (w/w) as surfactant mixture (S_mix) and water. The optimum formulation P2_TD resisted aqueous dilution, exhibited reasonable drug loading (2.45 mg/mL) and globule size (25.04 nm), acceptable pH and viscosity for pulmonary administration, and could be aerosolized using a jet nebulizer. Moreover, P2_TD demonstrated stability following sterilization and a favorable safety profile confirmed by both in-vitro and in-vivo toxicity studies. These favorable findings make P2_TD promising for the treatment of pediatric PAH.

Scientific and regulatory activities initiated by the U.S. food and drug administration to foster approvals of generic dry powder inhalers: Quality perspective

Regulatory science for generic dry powder inhalation products worldwide has evolved over the last decade. The revised draft guidance Metered Dose Inhaler (MDI) and Dry Powder Inhaler (DPI) Products - Quality Considerations [1] (Revision 1, April 2018) that FDA issued summarizes product considerations and potential critical quality attributes (CQAs). This guidance emphasizes the need to apply the principles of quality by design (QbD) and elements of pharmaceutical development discussed in the International Conference for Harmonisation of (ICH) guidelines. Research studies related to quality were used to support guidance recommendations, which preceded the first approval of a generic DPI product in the U.S. This review outlines scientific and regulatory hurdles that need to be surmounted to successfully bring a generic DPI to the market. The goal of this review focuses on relevant issues and various challenges pertaining to CMC topics of the generic DPI quality attributes. Furthermore, this review provides recommendations to abbreviated new drug application (ANDA) applicants to expedite generic approvals.

Spray Dried Rugose Lipid Particle Platform for Respiratory Drug Delivery

PURPOSE

To develop a new lipid-based particle formulation platform for respiratory drug delivery applications. To find processing conditions for high surface rugosity and manufacturability. To assess the applicability of the new formulation method to different lipids.

METHODS

A new spray drying method with a simplified aqueous suspension feedstock preparation process was developed for the manufacture of rugose lipid particles of 1,2-distearoyl-sn-glycero-3-phosphocholine (DSPC). A study covering a wide range of feedstock temperatures and outlet temperatures was conducted to optimize the processing conditions. Aerosol performance was characterized in vitro and in silico to assess the feasibility of their use in respiratory drug delivery applications. The applicability of the new spray drying method to longer-chain phospholipids with adjusted spray drying temperatures was also evaluated.

RESULTS

Highly rugose DSPC lipid particles were produced via spray drying with good manufacturability. A feedstock temperature close to, and an outlet temperature lower than, the main phase transition were identified as critical in producing particles with highly rugose surface features. High emitted dose and total lung dose showed promising aerosol performance of the produced particles for use as a drug loading platform for respiratory drug delivery. Two types of longer-chain lipid particles with higher main phase transition temperatures, 1,2-diarachidoyl-sn-glycero-3-phosphocholine (DAPC) and 1,2-dibehenoyl-sn-glycero-3-phosphocholine (22:0 PC), yielded similar rugose morphologies when spray dried at correspondingly higher processing temperatures.

CONCLUSIONS

Rugose lipid particles produced via spray drying from an aqueous suspension feedstock are promising as a formulation platform for respiratory drug delivery applications. The new technique can potentially produce rugose particles using various other lipids.

The future of dry powder inhaled therapy: Promising or Discouraging for systemic disorders?

Dry powder inhalation therapy has been shown to be an effective method for treating respiratory diseases like asthma, Chronic Obstructive Pulmonary Diseases and Cystic Fibrosis. It has also been widely accepted and used in clinical practices. Such success has led to great interest in inhaled therapy on treating systemic diseases in the past two decades. The current coronavirus (COVID-19) pandemic also has increased such interest and is triggering more potential applications of dry powder inhalation therapy in vaccines and antivirus drugs. Would the inhaled dry powder therapy on systemic disorders be as encouraging as expected? This paper reviews the marketed and in-development dry powder inhaler (DPI) products on the treatment of systemic diseases, their status in clinical trials, as well as the potential for COVID-19 treatment. The advancements and unmet problems on DPI systems are also summarized. With countless attempts behind and more challenges ahead, it is believed that the dry powder inhaled therapy for the treatment of systemic disorders still holds great potential and promise.

State-of-the-Art Review of The Application and Development of Various Methods of Aerosol Therapy

Aerosol therapy is a rapidly developing field of science. Due to a number of advantages, the administration of drugs to the body with the use of aerosol therapy is becoming more and more popular. Spraying drugs into the patient's lungs has a significant advantage over other methods of administering drugs to the body, including injection and oral methods. In order to conduct proper and effective aerosol therapy, it is necessary to become familiar with the basic principles and applications of aerosol therapy under various conditions. The effectiveness of inhalation depends on many factors, but most of all on: the physicochemical properties of the sprayed system, the design of the medical inhaler and its correct application, the dynamics of inhalation (i.e. the frequency of breathing and the volume of inhaled air). It is worth emphasizing that respiratory system diseases are one of the most frequently occurring and fastest growing diseases in the world. Accordingly, in recent years, a significant increase in the number of new spraying devices and pharmaceutical drugs for spraying has appeared on the market. It should also be remembered that the process of spraying a liquid is a complicated and complex process, and its efficiency is very often characterized by the use of micro- and macro parameters (including average droplet diameters or the spectrum of droplet diameter distribution). In order to determine the effectiveness of the atomization process and in the delivery of drugs to the patient's respiratory tract, the analysis of the size of the generated aerosol droplets is most often performed. Based on the proposed literature review, it has been shown that many papers dealt with the issues related to aerosol therapy, the selection of an appropriate spraying device, the possibility of modifying the spraying devices in order to increase the effectiveness of inhalation, and the possibility of occurrence of certain discrepancies resulting from the use of various measurement methods to determine the characteristics of the generated aerosol. The literature review presented in the paper was prepared in order to better understand the spraying process. Moreover, it can be helpful in choosing the right medical inhaler for a given liquid with specific rheological properties. The experimental data contained in this study are of great cognitive importance and may be of interest to entities involved in pharmaceutical product engineering (in particular in the case of the production of drugs containing liquids with complex rheological properties).

Mesoporous silica nanoparticles for pulmonary drug delivery

Over the last years, respiratory diseases represent a clinical concern, being included among the leading causes of death in the world due to the lack of effective lung therapies, mainly ascribed to the pulmonary barriers affecting the delivery of drugs to the lungs. In this way, nanomedicine has arisen as a promising approach to overcome the limitations of current therapies for pulmonary diseases. The use of nanoparticles allows enhancing drug bioavailability at the target site while minimizing undesired side effects. Despite different approaches have been developed for pulmonary delivery of drugs, including the use of polymers, lipid-based nanoparticles, and inorganic nanoparticles, more efforts are required to achieve effective pulmonary drug delivery. This review provides an overview of the clinical challenges in main lung diseases, as well as highlighted the role of nanomedicine in achieving efficient pulmonary drug delivery. Drug delivery into the lungs is a complex process limited by the anatomical, physiological and immunological barriers of the respiratory system. We discuss how nanomedicine can be useful to overcome these pulmonary barriers and give insights for the rational design of future nanoparticles for enhancing lung treatments. We also attempt herein to display more in detail the potential of mesoporous silica nanoparticles (MSNs) as promising nanocarrier for pulmonary drug delivery by providing a comprehensive overview of their application in lung delivery to date while discussing the use of these particles for the treatment of respiratory diseases.

Dry Powder Inhalers in the Digitalization Era: Current Status and Future Perspectives

During the last decades, the term "drug delivery systems" (DDSs) has almost fully replaced previously used terms, such as "dosage forms", in an attempt to emphasize the importance of the drug carrier in ensuring the claimed safety and effectiveness of the product. However, particularly in the case of delivery devices, the term "system", which by definition implies a profound knowledge of each single part and their interactions, is not always fully justified when using the DDS term. Within this context, dry powder inhalers (DPIs), as systems to deliver drugs via inhalation to the lungs, require a deep understanding of the complex formulation-device-patient interplay. As of now and despite the progress made in particle engineering and devices design, DPIs' clinical performance is limited by variable patients' breathing patterns. To circumvent this pitfall, next-generation DPIs should ideally adapt to the different respiratory capacity of individuals across age, health conditions, and other related factors. In this context, the recent wave of digitalization in the health care and industrial sectors may drive DPI technology towards addressing a personalized device-formulation-patient liaison. In this review, evolving technologies are explored and analyzed to outline the progress made as well as the gaps to fill to align novel DPIs technologies with the systems theory approach.

Status of inhalable antimicrobial agents for lung infection: progress and prospects

Introduction: Available parenteral and oral administration of antimicrobial agents (AMAs) in respiratory infections often show less penetration into the lung parenchyma. Due to inappropriate dose availability, the rate of antibiotic resistance is increasing gradually. Inhaled antibiotics intensely improve the availability of drugs at the site of respiratory infections. This targeted delivery minimizes systemic exposure and associated toxicity.Area covers: This review was performed by searching in the scientific database like PubMed and several trusted government sites like fda.gov, cdc.gov, ClinicalTrials.gov, etc. For better understanding, AMAs are classified in different stages of approval. Mechanism and characterization of pulmonary drug deposition section helps to understand the effective delivery of AMAs to the respiratory tract. There is a need for proper adoption of delivery devices for inhalable AMAs. Thus, delivery devices are extensively explained. Inspiratory flow has a remarkable impact on the delivery device that has been explained in detail.Expert opinion: Pulmonary delivery restricts the bulk administration of drugs in comparison with other routes. Therefore, novel AMAs with higher bactericidal activity at lower concentrations need to be synthesized. Extensive research is indeed in developing innovative delivery devices that would able to deliver higher doses of AMAs through the pulmonary route.

Choosing the right inhaler for the right patient: Considerations for effective management of patients with chronic obstructive pulmonary disease or asthma

BACKGROUND AND PURPOSE

Effective management of chronic respiratory disorders such as chronic obstructive pulmonary disease and asthma necessitates that patients inhale their medication. However, lack of detailed guidelines on the technological and mechanical functions of inhalers limits the ability of health care providers (HCPs) to personalize inhaler choice for patients. Numerous types of inhalers are currently available which offer their own distinct advantages and disadvantages. Independent of the drug class, the choice of inhaler may be influenced by many factors (e.g., inhaler attributes and the efficiency with which it delivers the medication, patient characteristics and preferences, dosing regimen, clinical setting, and support available for both patients and HCPs). This article attempts to summarize the inhalation technology and factors influencing inhaler choice and use and to provide an approach for matching the right inhaler to the right patient.

CONCLUSIONS

Identifying factors related to inhaler choice is critical to ensuring adherence to treatment and patients' ability to use their inhaler correctly.

IMPLICATIONS FOR PRACTICE

This review will help HCPs engage their patients in decision-making for inhaler choice and facilitate selection of the correct inhaler for each patient (i.e., one that they will use).

Understanding the Knowledge Gap and Assessing Comfort Level among Healthcare Professionals Who Provide Inhaler Education

Inhaled medications play a pivotal role in the management of COPD and asthma. Provider knowledge and ability to teach various devices is paramount as poor inhaler technique directly correlates with worse disease control. The goal of our survey was to assess the knowledge and comfort level with various inhaled devices among providers involved in patient inhaler education. We constructed a 20-question survey consisting of a five-question Likert scale-based comfort assessment and a 15-question multiple-choice inhaler knowledge test that was distributed both internally and nationwide. Groups surveyed included internal medicine residents, family medicine residents, pulmonary fellows, respiratory therapists, nursing staff, and pharmacists. A total of 557 providers responded to the survey. The overall correct response rate among all respondents was only 47%. There was no significant difference between correct response rates among prescribers (internal medicine residents, family medicine residents, and pulmonary fellows) and non-prescribers (respiratory therapists, nursing staff, and pharmacists), 47% and 47%, respectively (p = 0.6919). However, respiratory therapists had the overall highest correct response rate of 85%. Over 72% of respondents indicated that they educate patients on inhaler technique as part of their clinical duties. Furthermore, the correct response rates for various inhaler devices varied with 55% among metered dose inhalers, 52% among dry powder inhalers, and 34% among soft-mist inhalers. Our study reveals that there is a continued need for education on the subject of inhaler devices among providers given their overall poor knowledge, particularly in an era of fast-changing inhaler devices. We continue without knowing what we teach.

Design and Characterizations of Inhalable Poly(lactic-co-glycolic acid) Microspheres Prepared by the Fine Droplet Drying Process for a Sustained Effect of Salmon Calcitonin

The present study aimed to develop inhalable poly (lactic-co-glycolic acid) (PLGA)-based microparticles of salmon calcitonin (sCT) for sustained pharmacological action by the fine droplet drying (FDD) process, a novel powderization technique employing printing technologies. PLGA was selected as a biodegradable carrier polymer for sustained-release particles of sCT (sCT/SR), and physicochemical characterizations of sCT/SR were conducted. To estimate the in vivo efficacy of the sCT/SR respirable powder (sCT/SR-RP), plasma calcium levels were measured after intratracheal administration in rats. The particle size of sCT/SR was 3.6 µm, and the SPAN factor, one of the parameters to present the uniformity of particle size distribution, was calculated to be 0.65. In the evaluation of the conformational structure of sCT, no significant changes were observed in sCT/SR even after the FDD process. The drug release from sCT/SR showed a biphasic pattern with an initial burst and slow diffusion in simulated lung fluid. sCT/SR-RP showed fine inhalation performance, as evidenced by a fine particle fraction value of 28% in the cascade impactor analysis. After the insufflation of sCT samples (40 µg-sCT/kg) in rats, sCT/SR-RP could enhance and prolong the hypocalcemic action of sCT possibly due to the sustained release and pulmonary absorption of sCT. From these observations, the strategic application of the FDD process could be efficacious to provide PLGA-based inhalable formulations of sCT, as well as other therapeutic peptides, to enhance their biopharmaceutical potentials.

Advances in nanotechnology and asthma

According to the World Health Organization, Asthma is the fastest-growing disease in the world alongside HIV/AIDS, and its socioeconomic burden exceeds the sum of HIV/AIDS and tuberculosis. Its high disability and mortality rates have become serious social and public health concerns. Asthma is a heterogeneous disease in which genetic polymorphisms interact with the environmental factors. While no specific treatment has been available for asthma due to its complex pathogenesis, the advances in nanotechnology have brought new hope for the early diagnosis, treatment, and prevention of asthma. Nanotechnology can achieve targeted delivery of drugs or genes, reduce toxic effects, and improve drug bioavailability. The nano-modifications of drugs and the development of new nano-drugs have become new research directions. Studies have demonstrated the safety and effectiveness of nanocarriers. However, many challenges still need to be overcome before nanotherapy can be applied in clinical practice. In this article we review the new research highlights in this area, with an attempt to explore the great potential and feasibility of nanotechnology in treating asthma.

Delivery of nucleic acids to ex vivo porcine airways using electrospray

AIM OF THE STUDY

Nucleic acid-based therapies have the potential to provide clinically meaningful benefit across a wide spectrum of lung disease. However, in vivo delivery remains a challenge. Here we examined the feasibility of using electrospray to deliver nucleic acids to both porcine tracheal tissue sections and whole lung ex vivo.

MATERIALS AND METHODS

The effect of electrospray solution, emitter gauge, flow rate and voltage on plasmid DNA integrity was examined by analyzing supercoiled:open circle structure ratio by gel electrophoresis. Optimal parameters were used to deliver luciferase DNA and mRNA and siRNA-FITC to tracheal tissue sections. Luciferase mRNA was delivered to whole porcine lungs ex vivo using a catheter and bronchoscope system. Luciferase activity and fluorescence were analyzed by luminometry and microscopy respectively.

RESULTS

The incidence of DNA plasmid nicking was greatest in a low salt solution without ethanol compared with 1% and 20% ethanol with salt. From a range of emitters tested, a 32 gauge emitter produced the best supercoiled:open circle structure ratio, likely because less voltage was required to produce a stable electrospray with this emitter. Lower flow rates also showed a trend towards reduced DNA nicking. GFP DNA electrosprayed at 5 kV and 6 kV resulted in lower levels of GFP expression in A549 lung cells following lipofection compared with 3 kV and 4 kV. Optimised parameters of 20% ethanol solution, 32 gauge emitter, low flow rates and voltages of 3-5 kV, nucleic acid molecules were successful for delivery of luciferase DNA and mRNA as well as siRNA-FITC to porcine tracheal tissue sections and for delivery of luciferase mRNA to whole porcine lungs via bronchoscope.

CONCLUSIONS

We report ex vivo delivery of nucleic acids to porcine lung tissue via electrospray and bronchoscopic electrospray delivery of nucleic acid to an ex vivo porcine lung model.

Dosing challenges in respiratory therapies

The pulmonary route of administration has been commonly used for local lung conditions such as asthma and chronic obstructive pulmonary disease (COPD). Recently, with the advent of new technologies available for both formulation and device design, molecules usually delivered at high doses, such as antibiotics and insulin to treat cystic fibrosis (CF) and diabetes, respectively, can now be delivered by inhalation as a dry powder. These molecules are generally delivered in milligrams instead of traditional microgram quantities. High dose delivery is most commonly achieved via dry powder inhalers (DPIs), breath activated devices designed with a formulated powder containing micronized drug with aerodynamic diameters between 1 and 5 µm. The powder formulation may also contain other excipients and/or carrier particles to improve the flowability and aerosol dispersion of the powder. A drawback with high doses is that the formulation contains a great number of fine particles, leading to a greater degree of cohesive forces, producing strongly bound agglomerates. With greater cohesive forces holding fine particles together, higher dispersion forces are needed for efficient de-agglomeration and aerosolisation. This requirement of greater dispersion forces has led to different dry powder formulations and vastly different inhaler designs. The purpose of this review is to evaluate the different formulation types, various DPI devices currently available, and how these affect the aerosolisation process and delivery of high dosed inhalable dry powder formulations to the lungs.

Co-Spray Dried Mannitol/Poly(amidoamine)-Doxorubicin Dry-Powder Inhaler Formulations for Lung Adenocarcinoma: Morphology, In Vitro Evaluation, and Aerodynamic Performance

nhaled chemotherapeutics have emerged as a promising regimen to combat lung cancer as they maximize local drug concentration while significantly reduce systemic exposure. However, the poor lung/systemic safety profiles and lack of clinically efficient formulations restrict the applicability of inhaled chemotherapeutics. This work developed a dry-powder inhaler (DPI) formulation that dispersed a pH-responsive poly(amidoamine) dendrimer-doxorubicin conjugate (G4-12DOX) into mannitol microparticles. The dendrimer conjugate only releases cytotoxic agents in response to intracellular pH drop, leading to reduced systemic and local toxicity. This work investigated the effect of G4-12DOX content on the microparticle size and morphology, redispersibility, in vitro cytotoxicity, and aerosol properties of the formulations. The spray-dried G4-12DOX/mannitol microparticles showed smooth and spherical morphology with 1-4 μm in diameter. As the content of the G4-12DOX conjugate in the microparticles increased, the size, and degree of aggregation of microparticles increased dramatically. The G4-12DOX/mannitol microparticles were readily redispersed in the aqueous environment, reverting to nanoscale dendrimer conjugates to escape alveolar phagocytosis. All DPI formulations demonstrated the similar cytotoxicity as the original conjugate against a lung adenocarcinoma cell line. The emitted dose (ED) and fine particle fraction (FPF) of the DPI formulations decreased as the content of G4-12DOX increased, but EDs and FPFs of all formulations fell within the range of 85-60% and 60-40%, which were higher than those of commercial products (EDs = 40-60%; FPFs = 12-40%). Therefore, the spray-dried dendrimer/mannitol microparticle is an efficient and practical DPI formulation for direct delivery of large dose of chemotherapeutics to lung tumors.

Nebulised antibiotherapy: conventional versus nanotechnology-based approaches, is targeting at a nano scale a difficult subject?

Nebulised antibiotics offer great advantages over intravenously administered antibiotics and other conventional antibiotic formulations. However, their use is not widely standardized in the current clinical practice. This is the consequence of large variability in the performance of nebulisers, patient compliance and a deficiency of robust preclinical and clinical data. Nebulised antibiotherapy may play a significant role in future pulmonary drug delivery treatments as it offers the potential to achieve both a high local drug concentration and a lower systemic toxicity. In this review, the physicochemical parameters required for optimal deposition to the lung in addition to the main characteristics of currently available formulations and nebuliser types are discussed. Particular attention will be focused on emerging nanotechnology based approaches which are revolutionizing inhaled therapies used to treat both infections and lung cancer. Promising carriers such as Trojan-Horse microparticles, liposomes, polymeric and lipid nanoparticulate systems have been investigated and proposed as viable options. In order to achieve site-specific targeting and to optimize the PK/PD balance critical nanoscale design parameters such as particle size, morphology, composition, rigidity and surface chemistry architecture must be controlled. Development of novel excipients to manufacture these nanomedicines and assessment of their toxicity is also a keystone and will be discussed in this review.

Pulmonary drug delivery system: newer patents

Inhalational route for drug delivery and desired effects has been known since centuries. This lung-targeted therapy has benefited asthmatics and those with chronic respiratory problems. The technique has evolved greatly from crude pots and pipes to modern sophisticated drug-dispensing devices. This mode is effective, rapid and safe. Its outcome, however, is majorly determined by drug formulation, device structure and patient's coordinating skill. In spite of great advances in this field, more efforts are required to meet the unmet needs. This noninvasive mode is being increasingly studied for transfer of drugs for systemic action with promising results. The present article is an attempt to capture the recent development and progress in this field and review relevant newer patents.

Improving the Efficiency of Respiratory Drug Delivery: A Review of Current Treatment Trends and Future Strategies for Asthma and Chronic Obstructive Pulmonary Disease

Asthma and chronic obstructive pulmonary disease (COPD) are heterogeneous airway diseases associated with significant morbidity and mortality. Pharmacological treatment is delivered primarily through the inhalation route using various devices. Optimal disease control is highly dependent upon patient adherence. Both patients with asthma and COPD are prone to exacerbations leading to hospitalization, which can significantly impact quality of life. Poor adherence is a complex and multifactorial problem that does not have one simple solution. However, it is the biggest risk factor for exacerbations and consequently high healthcare utilization. This review discusses the complex and multifactorial obstacles that impact patient adherence as well as the effect on overall treatment outcomes and healthcare utilization. We also critically examined and compared relatively recent improvements in breath-activated pressurized metered dose inhalers, dry powder inhalers, and e-technology in asthma and COPD. Finally, future treatment strategies for better patient compliance such as personalized medicine and the importance of decision-making between patients and physicians were highlighted.

Pulmonary delivery of nanoparticle chemotherapy for the treatment of lung cancers: challenges and opportunities

Lung cancer is the second most prevalent and the deadliest among all cancer types. Chemotherapy is recommended for lung cancers to control tumor growth and to prolong patient survival. Systemic chemotherapy typically has very limited efficacy as well as severe systemic adverse effects, which are often attributed to the distribution of anticancer drugs to non-targeted sites. In contrast, inhalation routes permit the delivery of drugs directly to the lungs providing high local concentrations that may enhance the anti-tumor effect while alleviating systemic adverse effects. Preliminary studies in animals and humans have suggested that most inhaled chemotherapies are tolerable with manageable pulmonary adverse effects, including cough and bronchospasm. Promoting the deposition of anticancer drugs in tumorous cells and minimizing access to healthy lung cells can further augment the efficacy and reduce the risk of local toxicities caused by inhaled chemotherapy. Sustained release and tumor localization characteristics make nanoparticle formulations a promising candidate for the inhaled delivery of chemotherapeutic agents against lung cancers. However, the physiology of respiratory tracts and lung clearance mechanisms present key barriers for the effective deposition and retention of inhaled nanoparticle formulations in the lungs. Recent research has focused on the development of novel formulations to maximize lung deposition and to minimize pulmonary clearance of inhaled nanoparticles. This article systematically reviews the challenges and opportunities for the pulmonary delivery of nanoparticle formulations for the treatment of lung cancers.

A review of co-milling techniques for the production of high dose dry powder inhaler formulation

Drug delivery by inhalation offers several advantages compared to other dosage forms, including rapid clinical onset, high bioavailability, and minimal systemic side effects. Drug delivery to the lung can be achieved as liquid suspensions or solutions in nebulizers and pressurized metered-dose inhalers (pMDI), or as dry powders in dry powder inhalers (DPIs). Compared to other delivery systems, DPIs are, in many cases, considered the most convenient as they are breath actuated and do not require the use of propellants. Currently, the delivery of low drug doses for the treatment of lung conditions such as asthma and chronic obstructive pulmonary disease are well established, with numerous commercial products available on the market. The delivery of low doses can be achieved from either standard carrier- or aggregate-based formulations, which are unsuitable in the delivery of high doses due to particle segregation associated with carrier active site saturation and the cohesiveness of micronized aggregates which have poor flow and de-agglomeration properties. High-dose delivery is required for the treatment of lung infection (i.e. antibiotics) and in the emerging application of drug delivery for the management of systemic conditions (i.e. diabetes). Therefore, there is a demand for new methods for production of high-dose dry powder formulations. This paper presents a review of co-mill processing, for the production of high-efficiency inhalation therapies, including the jet mill, mechanofusion, or ball mill methodologies. We investigate the different techniques, additives, and drugs studied, and impact on performance in DPI systems.

How can nanoparticles contribute to antituberculosis therapy?

Therapeutic approaches using nanoparticles are being successfully used in foods and in several fields of medicine, including infectious diseases. Regarding tuberculosis (TB) treatment, nanoparticles can be a useful strategy for two distinct applications: (i) for their intrinsic antimycobacterial activity; (ii) as vehicles for known antitubercular drugs to allow reduction of dose- and drug-associated side-effects and administration via user-friendly administration routes such as pulmonary or oral ones. Promising results were obtained in vitro and in animal Mycobacterium tuberculosis models and need now to be translated into clinical drug candidates. Such a prospect can provide an opportunity regarding the current limited therapeutic options for drug-resistant TB and the scarcity of novel antituberculosis drugs in the drug discovery pipeline.

Advanced Therapeutic Strategies for Chronic Lung Disease Using Nanoparticle-Based Drug Delivery

Chronic lung diseases include a variety of obstinate and fatal diseases, including asthma, chronic obstructive pulmonary disease (COPD), cystic fibrosis (CF), idiopathic pulmonary fibrosis (IPF), and lung cancers. Pharmacotherapy is important for the treatment of chronic lung diseases, and current progress in nanoparticles offers great potential as an advanced strategy for drug delivery. Based on their biophysical properties, nanoparticles have shown improved pharmacokinetics of therapeutics and controlled drug delivery, gaining great attention. Herein, we will review the nanoparticle-based drug delivery system for the treatment of chronic lung diseases. Various types of nanoparticles will be introduced, and recent innovative efforts to utilize the nanoparticles as novel drug carriers for the effective treatment of chronic lung diseases will also be discussed.

Dry powder inhalable formulations for anti-tubercular therapy

Tuberculosis (TB) is an intracellular infectious disease caused by the airborne bacterium, Mycobacterium tuberculosis. Despite considerable research efforts, the treatment of TB continues to be a great challenge in part due to the requirement of prolonged therapy with multiple high-dose drugs and associated side effects. The delivery of pharmacological agents directly to the respiratory system, following the natural route of infection, represents a logical therapeutic approach for treatment or vaccination against TB. Pulmonary delivery is non-invasive, avoids first-pass metabolism in the liver and enables targeting of therapeutic agents to the infection site. Inhaled delivery also potentially reduces the dose requirement and the accompanying side effects. Dry powder is a stable formulation of drug that can be stored without refrigeration compared to liquids and suspensions. The dry powder inhalers are easy to use and suitable for high-dose formulations. This review focuses on the current innovations of inhalable dry powder formulations of drug and vaccine delivery for TB, including the powder production method, preclinical and clinical evaluations of inhaled dry powder over the last decade. Finally, the risks associated with pulmonary therapy are addressed. A novel dry powder formulation with high percentages of respirable particles coupled with a cost effective inhaler device is an appealing platform for TB drug delivery.

Nanotechnology approaches for inhalation treatment of lung diseases

Local administration of therapeutics by inhalation for treatment of lung diseases has the ability to deliver drugs, nucleic acids and peptides specifically to the site of their action and therefore enhance the efficacy of the treatment, limit the penetration of nebulized therapeutic agent(s) into the bloodstream and consequently decrease adverse systemic side effects of the treatment. Nanotechnology allows for a further enhancement of the treatment efficiency. The present review analyzes modern therapeutic approaches of inhaled nanoscale-based pharmaceutics for the detection and treatment of various lung diseases.

Drug Delivery Approaches in Addressing Clinical Pharmacology-Related Issues: Opportunities and Challenges

Various drug delivery approaches can be used to maximize therapeutic efficacy and minimize side effects, by impacting absorption, distribution, metabolism, and elimination (ADME) of a drug compound. For those drugs with poor water solubility or low permeability, techniques such as amorphous solid dispersion, liposomes, and complexations have been used to improve their oral bioavailability. Modified release (MR) formulations have been widely used to improve patient compliance, as well as to reduce side effects, especially for those drugs with short half-lives or narrow therapeutic windows. More than ten drugs using sterile long-acting release (LAR) formulations with clear clinical benefit have been successfully marketed. Furthermore, drug delivery systems have been used in delaying drug clearance processes. Additionally, modifying the in vivo drug distribution using targeted delivery systems has significantly improved oncology treatments. All the drug delivery approaches have their advantages and limitations. For both brand and generic drugs, the achievement of consistent quality and therapeutic performance using drug delivery systems can also pose serious challenges in developing a drug for the market, which requires close collaboration among industry, academia, and regulatory agencies. With the advent of personalized medicines, there will be great opportunities and challenges in utilizing drug delivery systems to provide better products and services for patients.