Effervescent excipients are used in powders and tablets. They are commonly used with acidic agents to cause a reaction that produces carbon dioxide. The carbon dioxide leads to a fizzing of the effervescent powder. Effervescent tablets and powders are widely used to deliver medicines contained antacids, pain medications, and cough or cold medicines. They dissolve quickly, are stable, convenient and easy to carry. Effervescents consist of a soluble organic acid and an alkali metal carbonate salt, one of which is often the active pharmaceutical ingredient (API). Common acids utilized for effervescent reactions are citric, malic, tartaric, adipic and fumaric acids.