Wikipedia says: "Hydroxychloroquine was approved for medical use in the United States in 1955.[1] It is on the World Health Organization's List of Essential Medicines, the safest and most effective medicines needed in a health system.[5] The wholesale cost in the developing world is about US$4.65 per month as of 2015, when used for rheumatoid arthritis or lupus.[6] In the United States the wholesale cost of a month of treatment is about US$25 as of 2020
That's old enough that there is no patent on the drug and I am sure many public domain synthesis paths: somebody might have a newer, better, cheaper way to make it which is patented, but there is no legal barrier to making it.
That's old enough that there is no patent on the drug and I am sure many public domain synthesis paths: somebody might have a newer, better, cheaper way to make it which is patented, but there is no legal barrier to making it.