Excipient (pharmacologically inactive substance)
What is it?
Carboxymethylcellulose appears as white, fibrous, free-flowing powder, and is used commonly as an FDA-approved disintegrant in pharmaceutical manufacturing. Disintegrants facilitate the breakup of a tablet in the intestinal tract after oral administration. Without a disintegrant, tablets may not dissolve appropriately and may effect the amount of active ingredient absorbed, thereby decreasing effectiveness. Carboxymethylcellulose is available in different salt forms, such as sodium or calcium.
Polymers of carboxymethylcellulose sodium are also the active ingredient in many over-the-counter dry-eye or "natural tears" products, such as Refresh Tears or TheraTears Lubricant Eye Drops.
According to the FDA Select Committee on GRAS food Substances, carboxymethylcellulose sodium is virtually unabsorbed. Carboxymethylcellulose sodium is 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