I know Medicine's not one of the more popular ones, but I'm amazed that it took this long for a busty one to show up. (And really, 820 pics would be damn good for a non-Touhou character)
There arent any "Big" jokes to make for Medicine as well to my knowledge. Daiyousei has the "Dai" in her name. The Aki sisters have "Bountiful harvets".
And even in the case of Wriggle. Her tomboy style is pretty much an excuse to make a big breasted wriggle. Medicine's popularity almost rivals the PC-98 characters, and thats saying alot.
The only doujin i can think of that i read where Medicine was a Prominent character amounts to a grand total of 2.And 1 of them is a simple origin story that trys to play off of canon. So its really just 1 doujin i read that actually tries to create a fanon Medicine. The name escapes me(I know its on my comp somewhere). Hina is also pretty "up" there as well for being on the bottom of the popularity sac.
There's also Touhou Bomber Yeah! (pool #1964) that gives Medicine a good amount of screentime, though she's paired with Yuuka. More Medicine fanart is always good. Though I was hoping for a Chinese dress (maybe later?), a more adult-bodied one is nice.
Actually it's more like 519 right now. The one you see from the gallery view is a different number (your 225 probably), though truth be told I never quite worked out what that is. You can see the actual count when viewing an image.