Cannabinoid pulmonary drug delivery systems for the treatment of COVID-19

Abstract

The Coronavirus Disease 2019 (COVID-19), caused by the Severe Acute Respiratory Distress Syndrome (SARS-Cov-2), was identified for the first time in late 2019 in China, resulting in a global pandemic of enormous impact. Despite a fast development and implementation of vaccination strategies, and the scouting of several pharmacological treatments, alternative effective treatments are still needed. In this regard, cannabinoids represent a promising approach, since they have been proven to exhibit several immunomodulatory and anti-inflammatory properties, some of them in COVID-19 in vitro models. However, they present unfavourable physicochemical properties and side effects due to unspecific biodistribution, including psychotropic effects, which hamper their pharmacological use. These limitations can be overcome by the use of a convenient drug delivery system, and/or through a local modality of administration, specifically the pulmonary route. To this purpose, several key factors determining the efficacy of the technological design must be controlled. This review work intended to assess the feasibility and convenience of a cannabinoid-based pulmonary treatment for COVID-19, ultimately identifying the most convenient drug delivery system for the purpose. To that aim, pharmacological properties of cannabinoids with potential application in COVID-19, as well as the state-of-the-art on pulmonary drug delivery systems, were reviewed. Finally, in the light of the reviewed information, a choice of drug delivery system was rationally proposed.