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Carbomer 941
(Any article currently titled Carbomer 941 that is manufactured without the use of benzene will be officially titled Carbomer Homopolymer after January 1, 2011.)
» Carbomer 941 is a high molecular weight polymer of acrylic acid cross-linked with allyl ethers of pentaerythritol. Carbomer 941, previously dried in vacuum at 80 for 1 hour, contains not less than 56.0 percent and not more than 68.0 percent of carboxylic acid (–COOH) groups. The viscosity of a neutralized 0.5 percent aqueous dispersion of Carbomer 941 is between 4000 and 11,000 centipoises.
Packaging and storage— Preserve in tight containers.
Change to read:
Labeling— Label it to indicate that it is not intended for internal use. A carbomer homopolymer manufactured using benzene and complying with the unique requirements of this monograph will be officially titled Carbomer 941 and will not be referred to as Carbomer Homopolymer.NF24
Viscosity— Proceed as directed in the test for Viscosity under Carbomer 934P, except to use a spindle having a disk 2.11 cm in diameter and 0.16 cm high attached to a shaft 0.32 cm in diameter, the distance from the top of the disk to the lower tip of the shaft being 2.7 cm, and the immersion depth being 4.92 cm (No. 5 spindle). The viscosity is between 4000 and 11,000 centipoises.
Limit of benzene— Proceed as directed in the test for Limit of benzene under Carbomer 934P, except to use about 20 mg of Carbomer 941, accurately weighed, instead of about 1 g of Carbomer 934P, to prepare the Test solution. Calculate the percentage of benzene in the portion of Carbomer 941 taken by the formula:
10(C/W)(rU / rS)
in which C is the concentration, in µg per mL, of benzene in the Standard solution; W is the weight, in mg, of Carbomer 941 taken to prepare the Test solution; and rU and rS are the benzene peak responses obtained from the Test solution and the Standard solution, respectively: not more than 0.5% is found.
Residual solvents 467: meets the requirements.
(Official January 1, 2007)
Other requirements— It meets the requirements for Identification, Loss on drying, Heavy metals, and Assay for carboxylic acid content under Carbomer 934P.
Auxiliary Information— Staff Liaison : Hong Wang, Ph.D. , Senior Scientific Associate
Expert Committee : (EM205) Excipient Monographs 2
USP29–NF24 Page 3294
Pharmacopeial Forum : Volume No. 31(2) Page 485
Phone Number : 1-301-816-8351