Quinine is readily available in Tonic Water for about a $1 a bottle.
Two questions come to mind
1. The Common Cold and COVID-19 are both of the same Corona Virus Family and there is No Cure for the Common Cold.
2. All your tests are in vitro but have you any anti virus research for analogs of Chloroquinine and Hydroxychloroquine?
If you have spare time Check my basic findings for the antiviral effects of common Quinine.
Note the that NIH mentions:
These antimalarial drugs quinine, chloroquine and mefloquine are antagonists and very similar in efficacy.
Currently the Chinese are investigating Chloroquine for patients with Coronavirus:
https://en.wikipedia.org/wiki/Chloroquine
https://en.wikipedia.org/wiki/Chloroquine#Research
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC1994240/
Coronavirus[
edit]
In trials conducted in China, chloroquine appears to be useful for
coronavirus disease 2019.
[12] See
§ Research for details.
These antimalarial drugs quinine, chloroquine and mefloquine are antagonists and very similar in efficacy.
Its history goes back to Peru (South America), where the indigenous people extracted the bark of the Cinchona[33] trees and used the extract (Chinchona officinalis) to fight chills and fever in the seventeenth century. In 1633 this herbal medicine was introduced in Europe, where it was given the same use and also began to be used against malaria.[34] The quinoline antimalarial drug quinine was isolated from the extract in 1820, and chloroquine is an analogue of this.