Absorption, and effect on gastric mucosa, of buffered and non-buffered tablets of acetylsalicylic acid.

The effect of buffered and non-buffered acetylsalicylic acid tablets on gastric mucosa and gastric distress was investigated in healthy volunteers and in patients with rheumatoid arthritis. The absorption of acetylsalicylic and salicylic acids was also measured. The absorption of salicylic acid was not affected in clinically significant amounts by buffering the tablets. Buffered tablets containing aluminum subacetate showed a slightly delayed absorption of salicylic acid. Damage to the gastric mucosa tended to be less after the preparation buffered by magnesium hydroxide. Subjective feelings to gastric distress were not affected by buffering.