Methacrylic Acid Copolymer Dispersion
»Methacrylic Acid Copolymer Dispersion is an aqueous dispersion of Methacrylic Acid Copolymer Type Cin water.It contains,on the basis of the calculated amount of dry substance in the Dispersion,not less than 46.0percent and not more than 50.6percent of methacrylic acid units.It may contain suitable surface-active agents.
Packaging and storage— Preserve in tight containers,at a temperature not exceeding 30.Protect from freezing.
Labeling— The label indicates the name and amount of any substance added as a surface-active agent.
Identification—
A:Infrared Absorption á197Kñ— Proceed as directed,except to use the residue obtained in the Loss on dryingtest as the test specimen.
B: Mix 10g of it with 0.3g of triethyl citrate,pour onto a glass slide,and allow the water to evaporate:a clear film is formed.
Viscosity á911ñ— Equip a suitable rotational viscosimeter with an adapter system consisting of a measuring cylinder and a spindle.The measuring cylinder has an internal diameter of 2.762cm and a depth of 13.50cm;the spindle is 2.515cm in diameter and 9.074cm in height,and has a shaft that is 0.40cm in diameter.Mix the Dispersion,pipet 16mLof it into the measuring cylinder,and adjust the temperature of the dispersion and the adapter to 20±0.1.With the spindle rotating at 30rpm,immediately observe and record the scale reading.Convert the scale reading to centipoises by multiplying the reading by the constant for the viscosimeter,the adapter system,and the speed employed.The viscosity is not more than 15centipoises.
pHá791ñ: between 2.0and 3.0.
Loss on drying á731ñ— Dry it at 110for 6hours:it loses between 68.5%and 71.5%of its weight.
Residue on ignition á281ñ— Using mild heating conditions (e.g.,steam bath,sand bath)to avoid loss of material,evaporate the Dispersion to dryness prior to ignition:not more than 0.2%residue is obtained,calculated on the undried Dispersion basis.
Heavy metals,Method IIá231ñ— Using mild heating conditions (e.g.,steam bath,sand bath)to avoid loss of material,evaporate the Dispersion to dryness prior to wetting with sulfuric acid and ignition:the color of the solution from the Test Preparationis not darker than that of the solution from the Standard Preparation(0.002%).
Limit of monomers—
pH2.0Phosphate buffer,fortieth-molar;Mobile phase;andChromatographic system— Prepare as directed in the test for Limit of monomers under Methacrylic Acid Copolymer.
Standard solution— Prepare a solution in methanol having a known concentration of about 2µg per mLeach of methacrylic acid and ethyl acrylate.To 50.0mLof this solution add 25.0mLof water,and mix.
Test solution— Dissolve 1.0g of the Dispersion in 50.0mLof methanol,add 25.0mLof water,and mix.
Procedure— Proceed as directed in the test for Limit of monomers under Methacrylic Acid Copolymer.The total amount of monomers found is not more than 0.01%,based on the weight of the Dispersion taken.
Coagulum content— Accurately weigh a stainless steel sieve having 90-µm openings,and filter 100g of the Dispersion through it.Wash the sieve with distilled water until a clear filtrate is obtained,and dry the sieve to constant weight at 110:the weight of the residue does not exceed 1000mg (1%).
Assay— Using about 2.5g of the Dispersion,accurately weighed,proceed as directed in the Assay under Methacrylic Acid Copolymer.Calculate,on the dried basis,the percentage of methacrylic acid units in the portion of Dispersion taken by the formula:
860.9[VN/W(100-L)],
in which Vis the volume,in mL,of titrant consumed;Nis the normality of the titrant;Wis the weight,in g,of Dispersion taken for the Assay;and Lis the percentage of the loss on drying value for the Dispersion.
Auxiliary Information— Staff Liaison:Catherine Sheehan,B.Sc.,Scientist
Expert Committee:(EMC)Excipients:Monograph Content
USP28–NF23Page 3036
Pharmacopeial Forum:Volume No.29(6)Page 2018
Phone Number:1-301-816-8262