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 940 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 shaft 0.32 cm in diameter, the distance from the top of the shaft to the lower tip of the shaft being 5.04 cm, and the immersion depth being 5.6 cm (No. 7 spindle). The viscosity is between 40,000 and 60,000 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 940, 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 940 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 940 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.
Other requirements—
It meets the requirements for
Identification, Loss on drying, Heavy metals, and
Assay for carboxylic acid content under
Carbomer 934P.
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 940 is between 40,000 and 60,000 centipoises.
467
:
meets the requirements.