Sodium croscarmellose is an internallycross-linked sodiumcarboxymethylcellulose for use as asuperdisintegrant in pharmaceutical formulations.[1]
E468 is theE number of crosslinked sodium carboxymethyl cellulose, used in food as anemulsifier.
The cross-linking reduces watersolubility while still allowing the material to swell (like asponge) and absorb many times its weight in water. As a result, it provides superior drugdissolution and disintegration characteristics, thus improving formulas′ subsequentbioavailability by bringing the active ingredients into better contact with bodily fluids.
Sodium croscarmellose also resolves formulators′ concerns over long-term functional stability, reduced effectiveness at high tablet hardness levels, and similar problems associated with other products developed to enhance drug dissolution. It is a very commonly used[2] pharmaceutical additive approved by theU.S. Food and Drug Administration. Its purpose in most tablets – including dietary supplements – is to assist the tablet in disintegrating in the gastrointestinal tract promptly. If a tablet disintegrating agent is not included, the tablet could disintegrate too slowly, in the wrong part of the intestine or not at all, thereby reducing the efficacy andbioavailability of the active ingredients.
Croscarmellose is made by first soaking crudecellulose insodium hydroxide, and then reacting the cellulose withsodium monochloroacetate to form sodiumcarboxymethylcellulose. Excess sodium monochloroacetate slowly hydrolyzes toglycolic acid and the glycolic acid catalyzes the cross-linkage to form sodium croscarmellose.[1]Chemically, it is the sodium salt of a cross-linked, partly O-(carboxymethylated) cellulose.
Sodium croscarmellose was first used as astabilizer in horse supplements.[citation needed]