Hydrogenated Soy Phosphatidylcholine Liposomes Stimulate Differential Expression of Chemokines And Cytokines by Rat Alveolar Macrophages In Vitro.

Liposomes are being developed as inhalable drug delivery systems, but concerns remain about their impact on the lungs. To better understand the impact of liposomes and their physicochemical properties on alveolar macrophages, the cytokine and chemokine expression profile of rat alveolar Nr8383 macrophages exposed to 0.1 and 1 mg/ml hydrogenated soy phosphatidylcholine (HSPC) liposomes was examined. Expression patterns varied considerably between liposomes in a concentration-dependent manner, with both anti- and pro-inflammatory chemokines/cytokines produced. Uncharged liposomes induce the greatest production of cytokines and chemokines, followed by PEGylated liposomes. The most significant increase in cytokine/chemokine expression was seen for IL-2 (up to 24-fold), IL-4 (up to 5-fold), IL-18 and VEGF (up to 10-fold), while liposome exposure significantly reduced MIP1 expression (5-fold). In summary, we demonstrate that liposome surface properties promote variable patterns of cytokine and chemokine secretion by alveolar macrophages. This suggests that the type of liposome employed may influence the type of immune response generated in the lung and by extension, dictate how inhaled liposomal nanomedicines affect the lungs response to inhaled toxicants and local infections.

Inhalable porous particles as dual micro-nano carriers demonstrating efficient lung drug delivery for treatment of tuberculosis.

Inhalation therapy treating severe infectious disease is among the more complex and emerging topics in controlled drug release. Micron-sized carriers are needed to deposit drugs into the lower airways, while nano-sized carriers are of preference for cell targeting. Here, we present a novel and versatile strategy using micron-sized spherical particles with an excellent aerodynamic profile that dissolve in the lung fluid to ultimately generate nanoparticles enabling to enhance both extra- and intra-cellular drug delivery (i.e., dual micro-nano inhalation strategy). The spherical particles are synthesised through the condensation of nano-sized amorphous silicon dioxide resulting in high surface area, disordered mesoporous silica particles (MSPs) with monodispersed size of 2.43 µm. Clofazimine (CLZ), a drug shown to be effective against multidrug-resistant tuberculosis, was encapsulated in the MSPs obtaining a dry powder formulation with high respirable fraction (F.P.F. <5 µm of 50%) without the need of additional excipients. DSC, XRPD, and Nitrogen adsorption-desorption indicate that the drug was fully amorphous when confined in the nano-sized pores (9-10 nm) of the MSPs (shelf-life of 20 months at 4 °C). Once deposited in the lung, the CLZ-MSPs exhibited a dual action. Firstly, the nanoconfinement within the MSPs enabled a drastic dissolution enhancement of CLZ in simulated lung fluid (i.e., 16-fold higher than the free drug), increasing mycobacterial killing than CLZ alone (p = 0.0262) and reaching concentrations above the minimum bactericidal concentration (MBC) against biofilms of M. tuberculosis (i.e., targeting extracellular bacteria). The released CLZ permeated but was highly retained in a Calu-3 respiratory epithelium model, suggesting a high local drug concentration within the lung tissue minimizing risk for systemic side effects. Secondly, the micron-sized drug carriers spontaneously dissolve in simulated lung fluid into nano-sized drug carriers (shown by Nano-FTIR), delivering high CLZ cargo inside macrophages and drastically decreasing the mycobacterial burden inside macrophages (i.e., targeting intracellular bacteria). Safety studies showed neither measurable toxicity on macrophages nor Calu-3 cells, nor impaired epithelial integrity. The dissolved MSPs also did not show haemolytic effect on human erythrocytes. In a nutshell, this study presents a low-cost, stable and non-invasive dried powder formulation based on a dual micro-nano carrier to efficiently deliver drug to the lungs overcoming technological and practical challenges for global healthcare.

Smart Specification Setting for Dry Powder Inhalation Carriers.

The specifications of excipients are important to pharmaceutical manufacturers to ensure that the final product can be manufactured robustly over the entire lifecycle of a drug product. Particle size specifications are key for dry powder inhalation excipients and they should be agreed between users and suppliers. The current paper evaluates two development strategies to set particle size specifications. It is shown that the application of quality-by-design principles to specification setting could result in broader specifications, while it guarantees that efficacy, safety and manufacturing of the medication is not affected. A multitude of reasons exist to keep specifications broader than the production capability range, including improved risk-mitigation and potentially reduced regulatory challenges during and after registration.

Antivirals and the Potential Benefits of Orally Inhaled Drug Administration in COVID-19 Treatment.

Coronavirus Disease 2019 (COVID-19) pandemic has been on the agenda of humanity for more than 2 years. In the meantime, the pandemic has caused economic shutdowns, halt of daily lives and global mobility, overcrowding of the healthcare systems, panic, and worse, more than 6 million deaths. Today, there is still no specific therapy for COVID-19. Research focuses on repurposing of antiviral drugs that are licensed or currently in the research phase, with a known systemic safety profile. However, local safety profile should also be evaluated depending on the new indication, administration route and dosage form. Additionally, various vaccines have been developed. But the causative virus, Severe Acute Respiratory Syndrome Coronavirus-2 (SARS-CoV-2), has undergone multiple variations, too. The premise that vaccines may suffice to eradicate new and all variants is unreliable, as they are based on earlier versions of the virus. Therefore, a specific medication therapy for COVID-19 is crucial and needed in order to prevent severe complications of the disease. Even though there is no specific drug that inhibits the replication of the disease-causing virus, among the current treatment options, systemic antivirals are the most medically appropriate. As SARS-CoV-2 directly targets the lungs and initiates lung damage, treating COVID-19 with inhalants can offer many advantages over the enteral/parenteral administration. Inhaled drug delivery provides higher drug concentration, specifically in the pulmonary system. This enables the reduction of systemic side effects and produces a rapid clinical response. In this article, the most frequently (systemically) used antiviral compounds are reviewed including Remdesivir, Favipiravir, Molnupiravir, Lopinavir-Ritonavir, Umifenovir, Chloroquine, Hydroxychloroquine and Heparin. A comprehensive literature search was conducted to provide insight into the potential inhaled use of these antiviral drugs and the current studies on inhalation therapy for COVID-19 was presented. A brief evaluation was also made on the use of inhaler devices in the treatment of COVID-19. Inhaled antivirals paired with suitable inhaler devices should be considered for COVID-19 treatment options.

Calculating the Charcoal Blockade Efficiency for Bioequivalence Study of Inhaled Ipratropium Bromide Using A Model Method.

Charcoal blockade is a useful approach to block gastrointestinal (GI) absorption of orally inhaled drug products (OIDPs) and therefore can be used effectively to determine drug absorption exclusively via the pulmonary route. Charcoal blockade efficiency (CBE) should be measured to show whether adequate blockade of GI exposure is achieved in bioequivalence (BE) study. The purpose of this study is to employ a model method to calculate the CBE for a pilot pharmacokinetic (PK) BE study of inhaled ipratropium bromide. This model method, based on a convolution integral, is built in-house using MATLAB package. The results demonstrated a full blockade of GI absorption of ipratropium bromide for both test and reference drug products. This study has shown that the model method may provide a useful approach for validation of charcoal blockade method used in PK BE study for OIDPs. The ability to use modeling may simplify human PK studies in general, and is particularly valuable when for ethical, technical or regulatory reasons administration of an orally swallowed form of the drug is not possible.

Assessment of nicotine release from nicotine-loaded chitosan nanoparticles dry powder inhaler formulations via locomotor activity of C57BL/6 mice.

PURPOSE: This study aimed to assess the activity of controlled release nicotine from dry powder inhaler formulation via locomotor activity of C57BL/6 mice. METHODS: To achieve this we built a nose-only inhalation device for pulmonary administration of nicotine to mice and determined the optimal operational parameters. We used the locomotor activity test to compare the effects of the inhaled nicotine hydrogen tartrate-loaded chitosan nanoparticles (NHT-CS) with NHT in C57BL/6 mice. The minimum inhaled dose of NHT-CS required to alter locomotor activity was compared with inhaled and subcutaneously (s.c) injected NHT. Finally, histological examination of lung tissues was performed to ensure inhalation of NHT-CS did not cause lung damage. RESULTS: We found a flow rate of 0.9 L/min and an exposure time of 5 min achieved optimal delivery of nicotine. A minimum of 0.88 mg inhaled of NHT-CS or 0.59 mg inhaled of NHT was required to alter locomotor activity similarly to injection of 0.5 mg/kg nicotine, suggesting the reformulation process did not alter the activity of NHT-CS. No differences between untreated and NHT-CS treated lung tissue upon histological examination were observed. CONCLUSIONS: The results indicated the inhaled NHT-CS is a viable preclinical option for developing novel inhalation formulations as a potential anti-smoking therapeutic.

Naked pDNA/hyaluronic acid powder shows excellent long-term storage stability and gene expression in murine lungs.

We evaluated the storage stability of powder containing naked plasmid DNA (pDNA) and hyaluronic acid (HA) or mannitol (Man) prepared by the spray-freeze-drying technique, through which we have reported high gene expression without any gene vectors. The powders composed of 5-10-µm porous particles and showing excellent dispersion were stored for 12 months under three storage conditions: 5 °C/Dry, 25 °C/Dry, and 25 °C/75% relative humidity. The humidified powders lost their porous shape within 1 week and were not suitable for inhalation characterization. On the other hand, the powders under dry conditions maintained high inhalation characteristics and pDNA integrity for 12 months. We administered the powders to the lungs of mice. The naked pDNA in HA powder showed significantly higher gene expression compared with that in Man powder and a pDNA-polyethylenimine complex solution. The gene expression of pDNA/HA powder was maintained for 12 months. These results suggest that powder containing naked pDNA is stable on storing under appropriate dry conditions and the naked pDNA/HA powder shows effective pulmonary gene expression.

Development of chitosan-coated liposome for pulmonary delivery of N-acetylcysteine.

The purpose of the present investigation was to formulate NAC (N-acetylcysteine)-loaded chitosan (CH)-coated liposome aiming at obtaining an effective formulation able to ensure a prolonged and controlled release of NAC to the lung by inhalation. Empty liposomes [(DPPG/Chol/DPPG with different molar percentages of DPPG) (0, 1, 2.5, 5)] were prepared and coated with CH at different CH/Lipid ratio (0.5, 1, 1.5,2, 2.5, W/W) to reach optimum coating of CH. TEM and SEM indicated that morphology of CH-coated and -uncoated liposomes were spherical. FTIR analysis indicated attachment of CH on liposome surface. The drug release experiment in the simulated lung fluid showed that the CH-uncoated and -coated liposomes released 51% and 38% of NAC during 9 h, respectively. The results showed that coating of liposome with CH resulted in the prolonged release of NAC from CH-coated liposome. The results of flow cytometry indicated the effective uptake of CH-coated liposome compared with the CH-uncoated liposome in epithelial cells. In vivo experiment indicated good deposition and retention of CH-coated liposome in lung in comparison with CH-uncoated liposome. The results of the present study demonstrated that CH-coated liposome may represent a promising carrier for the delivery of NAC to the lungs by inhalation therapy.

Influence of stabilizer type and concentration on the lung deposition and retention of resveratrol nanosuspension-in-microparticles.

The purpose of this study was to explore the influence of stabilizer type and concentration on the properties of spray dried nanosuspension-in-microparticles (NS-in-MPs) for inhalation. Taking resveratrol (RES) as a Biopharmaceutical Classification System II (BCS II) model drug, the RES containing nanosuspensions were fabricated by high pressure homogenization method with different stabilizers including sodium dodecyl sulphate (SDS), sodium alginate (SA), chitosan (CS) and polyvinyl alcohol (PVA). Then, the nanosuspensions were spray dried with mannitol to obtain inhalable NS-in-MPs. The particle size, morphology, drug existing state, in vitro aerodynamic performance, in vitro release behavior, lung retention and pharmacokinetic behaviors were characterized. It was found that the morphology, lung deposition as well as in vitro drug release from the microparticles were significantly influenced by stabilizer type, with 1% PVA as stabilizer presenting the highest fine particle fraction (FPF). Meanwhile, taking PVA as an example, it was found stabilizer concentration could alter morphology and flowability of the microparticles, and the FPF value decreased with the increase of stabilizer concentration. Further drug retention and in vivo pharmacokinetic studies demonstrated that the positively charged stabilizer CS could facilitate drug retention and minimize drug expose to the systemic circulation. In conclusion, the deposition and lung retention behavior of NS-in-MPs could be well tuned by selecting different type or concentration of stabilizers, which could facilitate local lung diseases therapy.

Evaluation of Bio-relevant Mouth-Throat Models for Characterization of Metered Dose Inhalers.

For inhalation drug characterization, the traditionally used USP induction port provides limited in vivo predictive capability because it does not adequately mimic airway geometry. In this study, various bio-relevant mouth-throat (MT) models, including Alberta Idealized Throat (AIT), and 3D printed large/medium/small-sized VCU (Virginia Commonwealth University) models were evaluated using two metered dose inhaler (MDI) drug products: a solution MDI containing beclomethasone dipropionate (BDP-MDI) and a suspension MDI containing fluticasone propionate (FP-MDI). For BDP-MDI, use of VCU large and small MT models resulted in a significantly higher MT deposition and lower fine particle fraction (FPF) compared with the other MT models. In the case of FP-MDI, the three VCU models resulted in higher MT deposition and lower FPF compared with the USP induction port and AIT. Overall, the in vitro testing results for the suspension MDI were more sensitive to geometric differences of the MT models than those for the solution MDI. Our results suggest that in vitro characterization of MDI products can be influenced by many factors, including the type of formulation, the MT geometry, shape, internal space volume, and the material used to make the MT models.

The future perspectives of natural materials for pulmonary drug delivery and lung tissue engineering.

INTRODUCTION: Search for new, functional biomaterials that can be used to synergistically deliver a drug, enhance its adsorption and stimulate the post-injury recovery of tissue function, is one of the priorities in biomedicine. Currently used materials for drug delivery fail to satisfy one or more of these functionalities, thus they have limited potential and new classes of materials are urgently needed. AREAS COVERED: Natural materials, due to their origin, physical and chemical structure can potentially fulfill these requirements and there is already strong evidence of their usefulness in drug delivery. They are increasingly utilized in various therapeutic applications due to the obvious advantages over synthetic materials. Particularly in pulmonary drug delivery, there have been limitations in the use of synthetic materials such as polymers and lipids, leading to an increase in the use of natural and protein-based materials such as silk, keratin, elastin and collagen. Literature search in each specialized field, namely, silk, keratin and collagen was conducted, and the benefits of each material for future application in pulmonary drug delivery are highlighted. EXPERT OPINION: The natural materials discussed in this review have been well established in their use for other applications, yet further studies are required in the application of pulmonary drug delivery. The properties exhibited by these natural materials seem positive for their application in lung tissue engineering, which may allow for more extensive testing for validation of pulmonary drug delivery systems.