**1. Introduction**

Ascorbic acid is needed by the body as an antioxidant, protecting infection, and building the immune system. Oral or systemic routes of administration in high doses have the consequence of increasing blood plasma levels, so they must be excreted by the kidneys and produce darker yellow urine. Urine that is excess of ascorbic acid supplementation is excreted is termed "expensive urine." Therefore, ascorbic acid supplementation by inhalation is an effective and efficient way in corona virus disease 2019 (COVID-19) pandemic. The hazard of transmission of the SARS CoV-2 virus through the air that hits the airway mucosa, can be anticipated to prevent it through increasing the mucosal immune system and anti-oxidative stress which has the potential to be contained in ascorbic acid.

Inhaled drugs, commonly used for the treatment of chronic lung disease, are intended to have their effect quickly reach the airways and are less absorbed into the bloodstream. Inhaled drugs, distributed via aerosol spray, mist, or powder that the patient inhales directly, which although the main effect of inhaled drugs is breathing, there may still be systemic effects as well.

Since time immemorial, there is a habit of squeezing the leaves, or fruit peels and inhaling the aroma for various diseases in the absence of sufficient information of

pharmacokinetics and pharmacodynamics of this ingredients. Citrus fruit, in particular, has shown the effect for the inflammation and infections including the common cold, including the potential benefit of ascorbic acid administration against the replication inhibitory activity of the SARS CoV-2 virus. The impact of ascorbic acid in the form of inhalation to the sinonasal mucosal immune system needs to be studied, considering the impact of ascorbic acid in the avoidance and plausible prognosis of COVID-19 is becoming increasingly necessary.
