As I understand it, the aquarium cleaning product in question is a mix of formaldehyde, hydrogen peroxide, copper sulphate and chloroquine. It is used to treat the fish parasite Amyloodinium ocellatum.

Taking a spoonful of that stuff is always a very bad idea.

Even if one could find "pure" Chloroquine Phosphate without all the other stuff, Chloroquine Phosphate is not the same as Chloroquine Phosphate. You can charge or remove electrons and still call it Chloroquine Phosphate, you can put it into different crystal formations, and I am probably forgetting other tricks that exist in chemistry to completely alter the behavior of a drug.