Ammonio Methacrylate Copolymer Dispersion
» Ammonio Methacrylate Copolymer Dispersion is an aqueous dispersion of Ammonio Methacrylate Copolymer Type A or B in water. It may contain suitable antimicrobial preservatives and alkalizing agents. The assay requirements differ for the two types, as set forth in the accompanying table.
Packaging and storage Preserve in tight containers, at a temperature not exceeding 25 for Type A, and not exceeding 30 for Type B. Protect from freezing.
Labeling Label it to state whether it is Type A or Type B. Label it to indicate the name and quantity of any added antimicrobial preservative or alkalizing agent.
USP Reference standards 11
USP Ammonio Methacrylate Copolymer Type A RS.
USP Ammonio Methacrylate Copolymer Type B RS.
Identification, Infrared Absorption 197K Proceed as directed, except to use the residue obtained in the test for Loss on drying as the test specimen.
Viscosity 911 Use a viscosimeter equipped with a spindle having a cylinder 1.88 cm in diameter and 6.51 cm high attached to a shaft 0.32 cm in diameter. The distance from the top of the cylinder to the lower tip of the shaft is 0.75 cm, and the immersion depth is 8.15 cm. Adjust the temperature to 20 ± 0.10. With the spindle rotating at 30 rpm, immediately record the scale reading. Multiply the scale reading by the constant for the viscosimeter spindle and speed employed, to obtain the viscosity in centipoises. The viscosity is not more than 100 centipoises.
Loss on drying 731 Dry it at 110 for 6 hours: it loses between 68.5% and 71.5% of its weight.
Residue on ignition 281 Using mild heating conditions (e.g., steam bath, sand bath, etc.) to avoid loss of material, evaporate the dispersion to dryness prior to ignition: not more than 0.5% of residue is obtained, calculated on the undried dispersion basis.
Limit of monomers Proceed as directed in the test for Limit of monomers under Ammonio Methacrylate Copolymer: not more than 0.002% of methyl methacrylate and not more than 0.008% of ethyl acrylate are found.
Coagulum content Accurately weigh a stainless steel sieve having 125-µm openings, and filter 100 g of Dispersion through it. Wash the sieve with distilled water until a clear filtrate is obtained, and dry the sieve to constant weight at 105: the weight of the residue does not exceed 1000 mg (1%).
Assay Dry under vacuum 2 g of Ammonio Methacrylate Copolymer Dispersion Type A, or 4 g of Ammonio Methacrylate Copolymer Dispersion Type B, at 90 for 30 minutes. Dissolve in 75 mL of glacial acetic acid at about 50, within about 30 minutes. After the solution has cooled down, add 25 mL of 0.6% cupric acetate solution in glacial acetic acid, and titrate with 0.1 N perchloric acid VS, determining the endpoint potentiometrically. Perform a blank titration, and make any necessary correction. Each mL of 0.1 N perchloric acid is equivalent to 20.772 mg of ammonio methacrylate (C9H18ClNO2) units.
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USP32NF27 Page 1164Pharmacopeial Forum: Volume No. 31(2) Page 483