Inhalation Delivery for the Treatment and Prevention of COVID-19 Infection

Abstract

Coronavirus disease-2019 (COVID-19) is caused by coronavirus-2 (SARS-CoV-2) and has produced a global pandemic. As of 22 June 2021, 178 million people have been affected worldwide, and 3.87 million people have died from COVID-19. According to the Centers for Disease Control and Prevention (CDC) of the United States, COVID-19 virus is primarily transmitted between people through respiratory droplets and contact routes. Since the location of initial infection and disease progression is primarily through the lungs, the inhalation delivery of drugs directly to the lungs may be the most appropriate route of administration for treating COVID-19. This review article aims to present possible inhalation therapeutics and vaccines for the treatment of COVID-19 symptoms. This review covers the comparison between SARS-CoV-2 and other coronaviruses such as SARS-CoV/MERS, inhalation therapeutics for the treatment of COVID-19 symptoms, and vaccines for preventing infection, as well as the current clinical status of inhaled therapeutics and vaccines.

What Happens to the Immune System after Vaccination or Recovery from COVID-19?

“…However, there are reports of COVID-19 transmission after the first and second doses of some types of vaccines [110,111]. Allam and Sayed (2021) reported a case in which a man (47 years old) from Saudi Arabia who received the first dose of BNT162b2 (Pfizer-BioNTech) became infected with COVID-19 and transmitted the infection to his family.…”

“…Consequently, Mercado and collaborators (2020) concluded that protection in both the upper and lower respiratory tracts will be required to prevent transmission and disease in humans [126,127]. In this regard, several COVID-19 inhaled vaccine candidates are in development, and they have shown good results in preclinical studies [111]. There are six vaccines that have progressed to clinical trials: 1) AdCOVID sponsored by Altimmune [128]; 2) MV-014-212 (Meissa) [129]; 3) Coroflu (Bharat Biotech; Precision Virologics; University of Wisconsin) [130]; 4) Ad5-nCoV (CanSino Biologics) [131]; 5) AZD12222 (AstraZeneca) [132] and 6) COVI-VAC (Codagenix Inc.) [133].…”

Synthesis, Physicochemical Characterization, In Vitro 2D/3D Human Cell Culture, and In Vitro Aerosol Dispersion Performance of Advanced Spray Dried and Co-Spray Dried Angiotensin (1—7) Peptide and PNA5 with Trehalose as Microparticles/Nanoparticles for Targeted Respiratory Delivery as Dry Powder Inhalers

“…Hence, pulmonary inhalation offers attractive advantages in delivering high drug concentrations directly to the lungs’ disease site, minimizing systemic bioavailability. Furthermore, delivering Ang (1—7) and PNA5 via inhalation to the lungs may compensate for the endogenous Ang (1—7) depletion due to ACE2 losing its function upon binding to SARS-CoV-2, thus represent a potential therapy for COVID-19 complications (e.g., the cytokine storm) [ 26 ].…”

Physicochemical Characteristics and In Vitro Toxicity/Anti-SARS-CoV-2 Activity of Favipiravir Solid Lipid Nanoparticles (SLNs)

“…As the route of SARS-CoV-2 infection and subsequent disease progression is within the lungs, the direct drug inhalation into the lungs seems the most suitable route to achieve high local deposition and rapid infection alleviation. Inhaled drug delivery for coronavirus treatment is preferable [12,13] over the systemic route [14,15] to avoid systemic side effects and first-pass metabolism [16][17][18][19]. In 2020, The International Society for Aerosols in Medicine (ISAM) issued an urgent appeal to policymakers and governmental agencies to urgently develop inhaled therapies for COVID-19 [20].…”