THE FUNCTION OF CMC IN THE PHARM INDUSTRY
CMC is an important excipient in the pharmaceutical field, valued for its water solubility, viscosity, film-forming ability, biocompatibility, and safety (FDA-approved). It is widely used in drug formulations, medical devices, and clinical treatments. Below are its main applications and mechanisms of action.
1. Applications in Drug Formulations
Tablets and Capsules
· Binder: Used in wet granulation (1%–5% concentration) to enhance powder cohesion and improve tablet compaction.
· Disintegrant: Low-substitution CMC absorbs water and swells, promoting rapid tablet disintegration (e.g., orally disintegrating tablets).
· Sustained-Release Matrix: High-viscosity CMC forms a gel layer to delay drug release (e.g., sustained-release tablets, gastro-floating tablets).
Liquid Formulations

• Thickening/Suspending Agent:

· Prevents particle sedimentation in oral suspensions (e.g., antacids, antibiotic suspensions).
· Adjusts viscosity in eye drops to prolong drug retention on the ocular surface (e.g., artificial tears).
· Stabilizer: Prevents phase separation in emulsions (e.g., fat emulsion injections).
Topical Preparations

• Gel Base: Used in water-soluble drug gels (e.g., anti-inflammatory analgesic gels) to provide suitable viscosity and spreadability.

• Ointments/Suppositories: Acts as a hydrophilic base to enhance drug release.

2. Medical Dressings and Wound Care

• Hydrocolloid Dressings:

· Combined with gelatin or pectin to form absorbent gels for exudative wounds (e.g., ulcers, burns).
· Maintains a moist environment to promote granulation tissue growth.

• Hemostatic Materials:

· Absorbs water and expands to compress blood vessels, aiding hemostasis (e.g., CMC  sponges).
· Combined with chitosan to enhance hemostatic effects.
3. Medical Devices and Interventional Therapy

• Anti-Adhesion Agent in Surgery:

· Forms absorbable films or gels to isolate surgical wounds (e.g., post-laparoscopic anti-adhesion).

• Catheter/Endoscope Lubricant: Serves as a water-soluble lubricating coating to reduce tissue friction.

4. Other Special Applications

• Artificial Tears: Mimics tear viscosity to relieve dry eye syndrome (e.g., CMC eye drops).

• Drug Carrier:

· Acts as a stabilizer in nanoparticle or microsphere preparations (e.g., anticancer drug carriers).
· Used as a mucoadhesive material in oral patches.

• Contrast Agent Suspension Aid: Maintains uniform suspension of barium sulfate in barium meal imaging.