Sodium bicarbonate Acetylsalicylic acid

Each Alka-Seltzer tablet contains 1916 mg of sodium bicarbonate, 1000 mg of citric acid (Fig. 9.1.2), and 325 mg of aspirin or acetylsalicylic acid (Fig. 9.1.3). Bromo Seltzer also contains sodium bicarbonate and citric acid as well as acetaminophen (Fig. 9.1.4). Several equilibria describe the action of bicarbonate-based antacid tablets. First of all, sodium bicarbonate dissolves completely in aqueous solution to generate sodium ions and bicarbonate ions ... 

The reactions in Table 13.8 show that carbon dioxide is a common product in many neutralization reactions. This is clearly displayed when a drop of vinegar (acetic acid) is added to baking soda (sodium bicarbonate). Some aspirin includes an antacid in their formulation to neutralize some of the acidity imparted by the aspirin (acetylsalicylic acid). These are commonly referred to as buffered aspirins. 

Numerous drugs are able to either enhance or inhibit the excretion of other drugs. For example, sodium bicarbonate enhances the excretion of phenobarbital. Probenecid interferes with the active secretion of penicillin and hence prolongs its half-life. Probenecid s uricosuric effects are counteracted by acetylsalicylic acid, which also possesses a uricosuric effect. When given concomitantly, both are excreted (see Chapter 24). 

Results The carbonic acid, the hypochlorous acid, the boric acid, and the acetylsalicylic acid turned the blue litmus paper to red, but had no effect on the red litmus paper. The sodium hydroxide and the ammonium hydroxide turned the red litmus paper to blue, but had no effect on the blue litmus paper. The sodium chloride, magnesium sulfate, ethanol, salad oil, and sodium bicarbonate had no effect on either the red or blue litmus paper. 

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