Carboxymethylcellulose: A Comprehensive Monograph on its Physicochemical Properties, Pharmacology, and Multifaceted Applications

1. Introduction and Chemical Profile

1.1. General Description and Classification

Carboxymethylcellulose (CMC), also known by its International Nonproprietary Name (INN) carmellose, is a water-soluble, anionic polymer derived from natural cellulose.[1] Structurally, it is a cellulose ether, specifically a derivative where carboxymethyl groups are attached to the hydroxyl groups of the glucopyranose units that form the cellulose backbone.[3] While classified as a "Small Molecule" in certain databases like DrugBank (ID: DB11059), its chemical nature and functional properties are those of a high-molecular-weight polysaccharide.[3] This distinction is fundamental to understanding its mechanism of action and diverse applications.

CMC is a multifaceted compound with a broad spectrum of uses. In medicine, it is primarily employed as an active pharmaceutical ingredient in two distinct therapeutic areas: as an ocular lubricant in artificial tear formulations to treat dry eye syndrome and as a bulk-forming laxative to manage constipation.[3] Beyond its role as an active ingredient, CMC is a ubiquitous pharmaceutical excipient, serving as a disintegrant, binder, and viscosity modifier in various dosage forms.[7] Its utility extends far beyond medicine into numerous industries, where it is valued as a thickener, stabilizer, and emulsifier in food, cosmetic, and manufacturing applications.[4] The most prevalent form used in these applications is its sodium salt, sodium carboxymethylcellulose, which enhances its solubility and functionality.[3]

1.2. Chemical Structure and Synthesis