Throughout history physicians and pharmacists have prepared, or compounded, drugs from raw ingredients.
Some pharmacists still do.
Legally in the US pharmacists can presemtly compound drugs that are made from substances that are on what is called a bulk drug list. However, had it been placed on the list, it could have been used for any indication. In other words, its use would not have been restricted to the eyes alone. Two hits come up. MSP was considered on the second day.