Citric Acid + Potassium Bicarbonate + Sodium Bicarbonate

Alka-Seltzer is an effervescent antacid and pain reliever first marketed by the Dr. Miles Medicine Company of Elkhart, Indiana, United States. Alka-Seltzer contains three active ingredients: aspirin (acetylsalicylic acid) (ASA), sodium bicarbonate, and anhydrous citric acid.[1] The aspirin is a pain reliever and anti-inflammatory, the sodium bicarbonate is an antacid, and the citric acid reacts with the sodium bicarbonate and water to form effervescence.[2] It ... [wikipedia]