The bioavailabilities of aspirin from an aspirin aluminum and an aspirin tablet and the effects of food and aluminum hydroxide gel.

The bioavailability of aspirin from an aspirin aluminum tablet was compared with that from an aspirin tablet in humans by determining total salicylate excreted in the urine. The effects of concomitant intakes of antacid or food on the bioavailability of aspirin were also investigated. The bioavailability of aspirin from an aspirin aluminum tablet was nearly 60% of that from an aspirin tablet. The low bioavailability of aspirin from an aspirin aluminum tablet was caused by slow release of aspirin from the aluminum complex, and not increased by concomitant intake of food. Intake of food, however, reduced both rate and extent of bioavailability of aspirin from an aspirin tablet, but dried aluminum hydroxide gel granules had no effect on the bioavailability of it.