Never looked at it before, but I found this:
Polyguacil is, but seems available only as eye drops and for injection into the retina.
You can't buy Ridostin online that I can find, but Larifan seems readily available.
http://www.larifans.lv/index.php/en/lariphan-activity
And this is very interesting:
https://www.ncbi.nlm.nih.gov/pubmed/?term=Lariphan