Excipient (pharmacologically inactive substance)
What is it?
Polysorbates are common excipient and solubilizing agents used in the pharmaceutical industry. For example, polysorbate 80 (also known as polyoxyethylene-sorbitan-20 mono-oleate, or Tween 80) is commonly used in the pharmaceutical and cosmetic industry in lotions, medical preparations (e.g., vitamin oils, vaccines, and intravenous preparations) and as an excipient in tablets. A solubilizing agent acts as a surfactant and increases the solubility of one agent in another. A substance that would not normally dissolve in a particular solution is able to dissolve with the use of a solubilizing agent.
 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