Cross Carmellose Sodium or sodium CMC, carboxymethylcellulose is a cross-linked polymer of sodium. It is a white, fibrous, free-flowing powder that is frequently employed as an FDA-approved disintegrant in the production of pharmaceuticals. After oral delivery, disintegrants make it easier for a pill to break up in the intestinal tract. Cross-linking provides for better medication solubility and increased bioavailability. Tablets without a disintegrant may not dissolve properly, which could affect how much of the active ingredient is absorbed and reduce effectiveness.