My doctor mentioned this, and the engineer in me thought it was extremely cool. So here’s how they got Xeljanz XR to work properly, so that it’s a once-daily pill instead of twice-daily: they coated it and put a hole in the end! What is Xeljanz? Xeljanz XR (for “extended release”) is a once-daily pill used to treat rheumatoid arthritis, psoriatic arthritis, and ulcerative colitis. It’s also being tested for ankylosing spondylitis currently. You may know it from its aggressive marketing campaign. The makers are really pushing the fact that it’s a pill, not an injection like many other similarly effective arthritis medications (biologics). Though not technically a biologic medication,…