Sodium carboxymethyl cellulose (CMC-Na) is an anionic water-soluble cellulose ether, which is made by alkalization and etherification modification of natural cellulose. Pharmaceutical-grade CMC complies with the pharmacopoeia standards of various countries (USP/EP/CP/JP), featuring high purity, safety and outstanding functional characteristics. It is widely used in oral preparations, topical preparations, ophthalmic preparations and sustained-release drug systems.
Appearance: White or off-white hygroscopic powder
Solubility: Readily soluble in water (soluble in cold water), insoluble in organic solvents
Viscosity range (2% aqueous solution, 25℃) : 5-50,000 mPa·s (customizable by grade)
Degree of substitution (DS) : 0.65-1.45 (precise control)
Functional Characteristics
- Thickening suspension: Forming pseudoplastic fluid to stabilize the suspension system
- Film-forming property: It can form transparent and flexible films
- Bioadhesion: Prolongs the retention time of drugs in mucous membranes (such as the mouth and eyes)
- pH tolerance: Stable within the pH range of 2 to 12
Detailed Explanation of Preparation Application
Oral preparation
Suspension agent
Recommended model: CMC-Na LV (low viscosity, 5-50 mPa·s)
Dosage: 0.2% - 1.5%
Case: Oral suspension of acetaminophen to prevent API sedimentation
Tablets
As a binder (wet granulation) : 2% - 6%
As a disintegrant (cross-linked CMC-Na) : 2% - 8%
Topical preparation
Gel matrix
Recommended model: CMC-Na MV (Medium viscosity, 1,000-5,000 mPa·s)
Dosage: 1% to 5%
Case: Clindamycin Acne Gel, improving drug loading uniformity
Ophthalmic preparations
Artificial tears
Recommended model: CMC-Na UL (Ultra-low viscosity, 5-25 mPa·s)
Dosage: 0.5% - 1.2%
Advantages: It simulates the viscoelasticity of natural tears and reduces the friction caused by blinking
Controlled-release system
Skeleton Piece
When used in combination with HPMC (CMC:HPMC=1:2-1:4
Control release mechanism: gel layer diffusion + dissolution