Excipient (pharmacologically inactive substance)
What is it?
Monosodium citrate (C6H7NaO7) is the monobasic sodium salt of citric acid. It has a sour taste similar to citric acid, and is salty as well. It is often used as a food preservative, and as a flavoring in the food industry. In the pharmaceutical industry it is used to control pH. It may be used as an alkalizing agent, buffering agent, emulsifier, or as a strong sequestering agent. Because it is less water-loving than citric acid, it may be preferable for dry formulations and tablets.
According to the FDA Select Committee on Generally Recognized as Safe (GRAS) food substances, citrate salts, including sodium citrate, are generally regarded as safe when used in normal quantities.
 Dave RH. Overview of pharmaceutical excipients used in tablets and capsules. Drug Topics (online). Advanstar. 10/24/2008 http://drugtopics.modernmedicine.com/drugtopics/Top+News/Overview-of-pharmaceutical-excipients-used-in-tabl/ArticleStandard/Article/detail/561047. Accessed 08/19/2011