Developed in Indiana and introduced in 1931, Alka-Seltzer? is a combination of sodium bicarbonate, aspirin and anhydrous citric acid, used for the relief of heartburn, acid indigestion and stomachaches. The over-the-counter remedy is marketed by Bayer Healthcare Consumer Care for relief of minor aches, pains, inflammation, fever, headache, heartburn, sour stomach, indigestion and hangovers; the Alka-Seltzer Plus? brand is designed to relive the discomfort of colds and flu and encompasses a range of products. The Alka-Seltzer? product line includes regular and extra strength antacid tablets and fruit chews designed to provide fast relief of heartburn, upset stomach, acid indigestion with headache, gas, bloating and body aches. Alka-Seltzer Plus? products include severe cold and flu effervescent tablets, severe sinus and congestion softgels, sinus and congestion day and night liquid gel capsules.