Update: Lewis and Short, via Logeion, provides an answer, but it's wrong:http://logeion.uchicago.edu/index.html#Crito
L&S marks the -i- of the name Crito as long (I confirmed this by looking at the print version), and cites Martial 11.60.6, which reads:
quod sanare Criton, non quod Hygia potest
"Phlogis has the unbridled sexual attraction that could extend old Priam's 'leather' and wouldn't let old Pelias be old, that everyone wants his girl to have, that Crito can heal but not Hygeia. Chione, by contrast, doesn't 'feel the work' and you'd think she was absent or made of marble . . . "
Here, however, -i- must be short
to fit the pentameter.
I don't understand the reference here. Criton seems to be Statilius Criton, the Trajan-era doctor from Asia Minor, author of a treatise on drugs, but I think the name is probably the same as that of the 5th-century Athenian from Socrates' circle.