This shot looks really grainy to me. however, it could just be the texture of the pills. I'm seeing it on the plastic case also though, but still could just be textures. I think that focus and clarity are ok, but lighting is a little harsh. A little bright on some of the white pills, and some distracting shadow on the left half of the shot.
I think this is a very nice photo with the square thing, however I'm not sure it would fit on a magazine cover. It's an interesting photo, and I could see how you would have it go on the front of the said magazine, however I think it would need some maniupulation and a top and bottom border.