Novel approach for low-dose pulmonary delivery of hydroxychloroquine in COVID-19

The In Vitro, In Vivo, and PBPK Evaluation of a Novel Lung-Targeted Cardiac-Safe Hydroxychloroquine Inhalation Aerogel

Hydroxychloroquine (HCQ) was repurposed for COVID-19 treatment. Subtherapeutic HCQ lung levels and cardiac toxicity of oral HCQ were overcome by intratracheal (IT) administration of lower HCQ doses. The crosslinker-free supercritical fluid technology (SFT) produces aerogels and impregnates them with drugs in their amorphous form with efficient controlled release. Mechanistic physiologically based pharmacokinetic (PBPK) modeling can predict the lung's epithelial lining fluid (ELF) drug levels. This study aimed to develop a novel HCQ SFT formulation for IT administration to achieve maximal ELF levels and minimal cardiac toxicity. HCQ SFT formulation was prepared and evaluated for physicochemical, in vitro release, pharmacokinetics, and cardiac toxicity. Finally, the rat HCQ ELF concentrations were predicted using PBPK modeling. HCQ was amorphous after loading into the chitosan-alginate nanoporous microparticles (22.7±7.6 μm). The formulation showed a zero-order release, with only 40% released over 30 min compared to 94% for raw HCQ. The formulation had a tapped density of 0.28 g/cm3 and a loading efficiency of 35.3±1.3%. The IT administration of SFT HCQ at 1 mg/kg resulted in 23.7-fold higher bioavailability, fourfold longer MRT, and eightfold faster absorption but lower CK-MB and LDH levels than oral raw HCQ at 4 mg/kg. The PBPK model predicted 6 h of therapeutic ELF levels for IT SFT HCQ and a 100-fold higher ELF-to-heart concentration ratio than oral HCQ. Our findings support the feasibility of lung-targeted and more effective SFT HCQ IT administration for COVID-19 compared to oral HCQ with less cardiac toxicity. Graphical abstract.

Recent Advances in Inhaled Nanoformulations of Vaccines and Therapeutics Targeting Respiratory Viral Infections

With the rapid outbreak of respiratory viral infections, various biological (e.g. vaccines, peptides, recombinant proteins, antibodies and genes) and antiviral agents (e.g. ribavirin, palivizumab and valaciclovir) have been successfully developed for the treatment of respiratory virus infections such as influenza, respiratory syncytial virus and SARS-CoV-2 infections. These therapeutics are conventionally delivered via oral, intramuscular or injection route and are associated with several adverse events due to systemic toxicity. The inherent in vivo instability of biological therapeutics may hinder them from being administered without proper formulations. Therefore, we have witnessed a boom in nanotechnology coupled with a needle-free administration approach such as the inhalation route for the delivery of complex therapeutics to treat respiratory infections. This review discussed the recent advances in the inhalation strategies of nanoformulations that target virus respiratory infections.

Safety, Tolerability, and Pharmacokinetics of Nebulized Hydroxychloroquine: A Pilot Study in Healthy Volunteers

Background: Early in the coronavirus disease 2019 (COVID-19) pandemic, hydroxychloroquine (HCQ) drew substantial attention as a potential COVID-19 treatment based on its antiviral and immunomodulatory effects in vitro. However, HCQ showed a lack of efficacy in vivo, and different groups of researchers attributed this failure to the insufficient drug concentration in the lung following oral administration (HCQ is only available in the market in the tablet form). Delivering HCQ by inhalation represents a more efficient route of administration to increase HCQ exposure in the lungs while minimizing systemic toxicity. In this pilot study, the safety, tolerability, and pharmacokinetics of HCQ nebulizer solution were evaluated in healthy volunteers. Methods: Twelve healthy participants were included in this study and were administered 2 mL of HCQ01 solution (equivalent to 25 mg of HCQ sulfate) through Aerogen^® Solo, a vibrating mesh nebulizer. Local tolerability and systemic safety were assessed by forced expiratory volume in the first and second electrocardiograms, clinical laboratory results (e.g., hematology, biochemistry, and urinalysis), vital signs, and physical examinations. Thirteen blood samples were collected to determine HCQ01 systemic exposure before and until 6 hours after inhalation. Results: The inhalation of HCQ01 was well tolerated in all participants. The mean value of C_max for the 12 participants was 9.66 ng/mL. T_max occurred at around 4.8 minutes after inhalation and rapidly decreased thereafter. The reported systemic exposure was very low with a mean value of 5.28 (0.6-15.6) ng·h/mL. Conclusion: The low systemic concentrations of HCQ01 of 9.66 ng/mL reported by our study compared with 1 μg/mL previously predicted after 200 mg BID oral administration, and the safety and tolerability of HCQ01 administered as a single dose through nebulization, support the assessment of its efficacy, safety, and tolerability in further studies for the treatment of COVID-19.

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.

Nebulised Isotonic Hydroxychloroquine Aerosols for Potential Treatment of COVID-19

The coronavirus disease 2019 (COVID-19) is an unprecedented pandemic that has severely impacted global public health and the economy. Hydroxychloroquine administered orally to COVID-19 patients was ineffective, but its antiviral and anti-inflammatory actions were observed in vitro. The lack of efficacy in vivo could be due to the inefficiency of the oral route in attaining high drug concentration in the lungs. Delivering hydroxychloroquine by inhalation may be a promising alternative for direct targeting with minimal systemic exposure. This paper reports on the characterisation of isotonic, pH-neutral hydroxychloroquine sulphate (HCQS) solutions for nebulisation for COVID-19. They can be prepared, sterilised, and nebulised for testing as an investigational new drug for treating this infection. The 20, 50, and 100 mg/mL HCQS solutions were stable for at least 15 days without refrigeration when stored in darkness. They were atomised from Aerogen Solo Ultra vibrating mesh nebulisers (1 mL of each of the three concentrations and, in addition, 1.5 mL of 100 mg/mL) to form droplets having a median volumetric diameter of 4.3-5.2 µm, with about 50-60% of the aerosol by volume < 5 µm. The aerosol droplet size decreased (from 4.95 to 4.34 µm) with increasing drug concentration (from 20 to 100 mg/mL). As the drug concentration and liquid volume increased, the nebulisation duration increased from 3 to 11 min. The emitted doses ranged from 9.1 to 75.9 mg, depending on the concentration and volume nebulised. The HCQS solutions appear suitable for preclinical and clinical studies for potential COVID-19 treatment.

Exploring the room for repurposed hydroxychloroquine to impede COVID-19: toxicities and multipronged combination approaches with pharmaceutical insights

Introduction: SARS-CoV-2 has fatally affected the whole world with millions of deaths. Amidst the dilemma of a breakthrough in vaccine development, hydroxychloroquine (HCQ) was looked upon as a prospective repurposed candidate. It has confronted numerous controversies in the past few months as a chemoprophylactic and treatment option for COVID-19. Recently, it has been withdrawn by the World Health Organization for its use in an ongoing pandemic. However, its benefit/risk ratio regarding its use in COVID-19 disease remains poorly justified. An extensive literature search was done using Scopus, PubMed, Google Scholar, www.cdc.gov, www.fda.gov, and who.int.Areas covered: Toxicity vexations of HCQ; pharmaceutical perspectives on new advances in drug delivery approaches; computational modeling (PBPK and PD modeling) overtures; multipronged combination approaches for enhanced synergism with antiviral and anti-inflammatory agents; immuno-boosting effects.Expert commentary: Harnessing the multipronged pharmaceutical perspectives will optimistically help the researchers, scientists, biotech, and pharmaceutical companies to bring new horizons in the safe and efficacious utilization of HCQ alone or in combination with remdesivir and immunomodulatory molecules like bovine lactoferrin in a fight against COVID-19. Combinational therapies with free forms or nanomedicine based targeted approaches can act synergistically to boost host immunity and stop SARS-CoV-2 replication and invasion to impede the infection.

Drug Repurposing in the COVID-19 Era: Insights from Case Studies Showing Pharmaceutical Peculiarities

COVID-19 may lead to severe respiratory distress syndrome and high risk of death in some patients. So far (January 2021), only the antiviral remdesivir has been approved, although no significant benefits in terms of mortality and clinical improvement were recently reported. In a setting where effective and safe treatments for COVID-19 are urgently needed, drug repurposing may take advantage of the fact that the safety profile of an agent is already well known and allows rapid investigation of the efficacy of potential treatments, at lower costs and with reduced risk of failure. Furthermore, novel pharmaceutical formulations of older agents (e.g., aerosolized administration of chloroquine/hydroxychloroquine, remdesivir, heparin, pirfenidone) have been tested in order to increase pulmonary delivery and/or antiviral effects of potentially active drugs, thus overcoming pharmacokinetic issues. In our review, we will highlight the importance of the drug repurposing strategy in the context of COVID-19, including regulatory and ethical aspects, with a specific focus on novel pharmaceutical formulations and routes of administration.

Development of a Physiologically-Based Pharmacokinetic (PBPK) Model of Nebulized Hydroxychloroquine for Pulmonary Delivery to COVID-19 Patients

Despite inconclusive evidence, chloroquine (CQ) and hydroxychloroquine (HCQ)are commonly used for the treatment of Corona virus Disease 2019(COVID-19) in critically ill patients.It was hypothesized that HCQ as an aerosol application can reach the antiviral concentration of ~1-5 μM in the alveolar cells which has been proven effective in vitro. A physiologically-based pharmacokinetic (PBPK) model of nebulized HCQ for pulmonary delivery to COVID-19 patients using the Nasal-Pulmonary Module in GastroPlus^® V9.7 simulator, in order to calculate the necessary inhalation dose regimen of HCQ, was developed. The physiological, drug disposition, and pharmacokinetic parameters were obtained from the literature and used during model building after optimization using Optimization Module, while oral data was used for validation. The 25 mg BID inhalation dosing was predicted to lead to alveolar HCQ levels of 7 µM (above EC50 of ~1-5 µM), and small plasma levels of 0.18 µM (as compared to plasma levels of 3.22 µM after 200 mg BID oral dosing). However, average contact time (>1 µM) is around 0.5 h in lung parts, suggesting indirect exposure response effect of HCQ.The developed PBPK model herein predicted HCQ levels in plasma and different lung parts of adults after multiple inhalation dosing regimens for 5 days. This in-silico work needs to be tested in vivo on healthy subjects and COVID-19 patients using 12.5 mg BID and 25 mg BID inhalation doses.