Croscarmellose sodium
[CAS# 74811-65-7]

Identification

• Classification: Analytical chemistry >> Standard >> Analytical standard
• Name: Croscarmellose sodium
• Molecular Formula: C₂₈H₃₀Na₈O₂₇
• CAS Registry Number: 74811-65-7
• EC Number: 629-739-2

Properties

• Solubility: 30 g/L (20 °C water)
• Melting point: >205 °

Discovery and Applications

Croscarmellose sodium is a chemically modified cellulose derivative widely used as a superdisintegrant in pharmaceutical formulations. It is produced by the cross-linking of sodium carboxymethyl cellulose, resulting in a highly absorbent and swelling polymer. The introduction of cross-links prevents the polymer from dissolving in water, while allowing it to rapidly absorb water and swell.

The discovery of croscarmellose sodium stems from advances in pharmaceutical excipient technology aimed at improving the dissolution and bioavailability of oral solid dosage forms. By the mid-20th century, cellulose derivatives were being explored extensively for their capacity to aid tablet disintegration. Croscarmellose sodium emerged as an effective excipient that could address challenges related to tablet hardness and dissolution rates.

In pharmaceutical applications, croscarmellose sodium serves primarily as a superdisintegrant in tablets and capsules. When these dosage forms come into contact with aqueous fluids in the gastrointestinal tract, croscarmellose sodium rapidly absorbs water and swells, exerting pressure on the tablet matrix. This swelling action facilitates the rapid breakup of the tablet into smaller fragments, increasing the surface area available for drug dissolution and absorption.

Its efficiency as a disintegrant has led to widespread use in immediate-release formulations of various drugs, improving onset of action and overall bioavailability. Additionally, it is used in orally disintegrating tablets and orally disintegrating films, where rapid disintegration in the mouth is desired without the need for water.

Croscarmellose sodium also finds use in controlled-release and sustained-release formulations as a functional excipient to modulate drug release profiles. Its swelling properties can influence the rate at which the drug is released from the dosage form, allowing for tailored therapeutic effects.

Beyond oral dosage forms, croscarmellose sodium has been employed in topical and ophthalmic formulations to enhance drug dispersion and absorption. It is valued for its non-toxic, inert, and biocompatible nature, making it suitable for a wide range of pharmaceutical products.

Manufacturing of croscarmellose sodium involves the etherification of cellulose with chloroacetic acid to form carboxymethyl cellulose, followed by controlled cross-linking using agents such as epichlorohydrin. The resulting product is a white to off-white, free-flowing powder that is easily incorporated into pharmaceutical formulations.

In conclusion, croscarmellose sodium is a cross-linked sodium carboxymethyl cellulose derivative discovered in the mid-20th century as part of pharmaceutical excipient development. It functions primarily as a superdisintegrant in oral solid dosage forms, enhancing drug dissolution and bioavailability. Its unique swelling properties, safety profile, and versatility have made it an essential excipient in the pharmaceutical industry.

References

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