Why does the way this drug works differ between manufacturers? My pharmacy has changed manufacturers 3 times in the past 2 years. They currently use one, but will get this med from Qualitest for me. It works, but not as well as their original on, which they claim is no longer availeble. I take this to reduce swelling in my extremadies (legs, feet, hands). Wouldn't all manufacturers be required to make this drug work the same way. The pharmacist said others have complained and inquired about the same thing, but she didn't do anything about it. I was persistant si they di order this manufacturer for me. If I were taking it for a heart condition, it would make a greater difference. So: what would be the difference in these 3 manufacturers?