[1] E468 is the E number of crosslinked sodium carboxymethyl cellulose, used in food as an emulsifier.
As a result, it provides superior drug dissolution and disintegration characteristics, thus improving formulas′ subsequent bioavailability 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 the U.S. Food and Drug Administration.
[1] Chemically, it is the sodium salt of a cross-linked, partly O-(carboxymethylated) cellulose.