Question

The makers of the analgesic Bufferin claim that their product buffers the fluid of the stomach at a higher pH, thereby avoiding the side effects of aspirin. What buffer is present in Bufferin? Is there enough buffer present in a couple of tablets to significantly raise the pH of the stomach fluid when taking aspirin?

Answer 1

Bufferin is a version of ASA (acetyl salicylic acid), a moderate-strength acid, that has been buffered with MgO.

It easily diffuses through the stomach lining and into the cells underneath. Once there, it encounters a much higher pH and ionizes again (preventing it from diffusing back into the stomach). Aspirin suppresses the production of prostaglandins- hormones that stimulate blood clotting, among other things. This causes capillaries in the stomach lining to leak. The amount of bleeding is small for most people, but in some cases it can result in serious blood loss. Bufferin prevent the acetyl salicylic acid to ionize and hence bleeding is stopped. It does not significant raise the ph of stomach fluid.