Carbopol is a white loose powder; it has a characteristic slightly odor; it has hygroscopicity and is a medicinal excipient. Carbopol is a high molecular polymer of acrylic acid bonded allyl sucrose or pentaerythritol allyl ether. Calculated according to the dry product, the carboxylic acid group (-COOH) should be 56.0%-68.0%.
Carbopol discolors with resorcinol and is incompatible with phenol, cationic polymers, strong acids and high concentrations of electrolytes.
Commonly used Carbopol has the following 11 different models:
1. Carbopol 940;
2. Carbopol 941;
3. Carbopol 934;
4. Carbopol 1342;
5. Carbopol 980;
6. Carbopol ETD 2020;
7. Carbopol AQUA SF-1;
8. carbopol Ultrez 21;
9. Carbopol Ultrez 20;
10. Pemulen TR-1;
11. Pemulen TR-2;
Different models are mainly different in viscosity. The following are the characteristics of commonly used models:
Carbopol940: short rheology, high viscosity, high clarity, low ion resistance and shear resistance, suitable for gels and creams.
Carbopol941: long rheology, low viscosity, high clarity, medium ion resistance and shear resistance, suitable for gels and emulsions.
Carbopol934: cross-linked polyacrylic resin, topical drug delivery system, stable at high viscosity, used in thick gels, emulsions, and suspensions.
