Excipient (pharmacologically inactive substance)
What is Cellulose?
Microcrystalline cellulose (C6H10O5)n is refined wood pulp. It is a white, free-flowing powder. Chemically, it is an inert substance, is not degraded during digestion and has no appreciable absorption. In large quantities it provides dietary bulk and may lead to a laxative effect.
Microcrystalline cellulose is a commonly used excipient in the pharmaceutical industry. It has excellent compressibility properties and is used in solid dose forms, such as tablets. Tablets can be formed that are hard, but dissolve quickly. Microcrystalline cellulose is the same as cellulose, except that it meets USP standards.
It is also found in many processed food products, and may be used as an anti-caking agent, stabilizer, texture modifier, or suspending agent among other uses. According to the Select Committee on GRAS Substances, microcrystalline cellulose 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
 Food and Agricultural Organization of the United Nations. Corporate Document Repository. Compendium of Food Additive Specifications, Addendum 5. Microcrystalline cellulose. http://www.fao.org/docrep/W6355E/w6355e0l.htm Accessed July 28, 2011
Top Medications Containing Cellulose
- Inderal LA 80 mg (Wyeth)
- Inderal LA 60 mg (Wyeth-Ayerst Laboratories)
- Inderal LA 120 mg (Wyeth-Ayerst Laboratories)
- Inderal LA 160 mg (Wyeth)
- Keflex 500 mg (Advancis Pharmaceutical Corporation)
- Keflex 750 mg (Advancis Pharmaceutical Corp)
- Keflex 250 mg (VICTORY PHARMA)
- Keflex 333 mg (Advancis Pharmaceutical Corporation)
- LONITEN 10 MG (Pharmacia Corp)
- LONITEN 2.5 MG (Pharmacia Corp)
- Pyrazinamide 500 mg (Mikart, Inc.)
- Simvastatin (Orally Disintegrating) 20 mg (Synthon Pharmaceuticals, Inc.)
- Simvastatin (Orally Disintegrating) 10 mg (Synthon Pharmaceuticals, Inc.)
- Simvastatin (Orally Disintegrating) 40 mg (Synthon Pharmaceuticals, Inc.)
- Simvastatin (Orally Disintegrating) 80 mg (Synthon Pharmaceuticals, Inc.)