Ethyl Acrylate and Methyl Methacrylate Copolymer Dispersion

[9010-88-2].

» Ethyl Acrylate and Methyl Methacrylate Copolymer Dispersion is an aqueous dispersion of a copolymer of ethyl acrylate and methyl methacrylate having an average molecular weight of about 800,000. It may contain suitable emulsifying agents.

Packaging and storage— Preserve in well-closed containers. Store between 5

and 25

, with excursions permitted up to 30

. Do not freeze.

Labeling— Label it to indicate the name and quantity of any added emulsifiers.

USP Reference standards

—
USP Ethyl Acrylate and Methyl Methacrylate Copolymer Dispersion RS.

Change to read:

Identification—

Place 1 drop of Ethyl Acrylate and Methyl Methacrylate Copolymer Dispersion on a glass plate,1 and cover the test substance with a water-resistant crystal disk (silver chloride or KRS-5).2 Gently press on and then remove the crystal disk. Dry the crystal disk at 80

for approximately 15 minutes: the IR absorption spectrum of Ethyl Acrylate and Methyl Methacrylate Copolymer Dispersion exhibits maxima corresponding to the same wavelengths as those of a similar preparation of USP Ethyl Acrylate and Methyl Methacrylate Copolymer Dispersion RS treated in the same manner.

NF27

Viscosity

911

— 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 2.762 cm and a depth of 13.50 cm; the spindle is 2.515 cm in diameter and 9.074 cm in height, and has a shaft that is 0.40 cm in diameter. Mix the Ethyl Acrylate and Methyl Methacrylate Copolymer Dispersion, pipet 16 mL into the measuring cylinder, and adjust the temperature of the Ethyl Acrylate and Methyl Methacrylate Copolymer Dispersion and the adapter to 20 ± 0.1

. With the spindle rotating at 30 rpm, 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 50 centipoises.

Microbial enumeration tests

and Tests for specified microorganisms

— The total aerobic microbial count does not exceed 1000 cfu per g and total yeast and mold count does not exceed 100 cfu per g.

791

: between 5.5 and 8.6.

Loss on drying

731

— Dry it at 110

for 3 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) to avoid loss of material, evaporate the Ethyl Acrylate and Methyl Methacrylate Copolymer Dispersion to dryness prior to ignition: not more than 0.4% residue is obtained, calculated on the undried basis.

Change to read:

Limit of monomers—

Sodium perchlorate solution— Dissolve 3.5 g of sodium perchlorate in 100 mL of water.

pH 2.0 Phosphoric acid— Dilute phosphoric acid with water to obtain a solution having a pH of 2.0.

Mobile phase— Prepare a mixture of pH 2.0 Phosphoric acid and methanol (80 : 20), filter, and degas. Make adjustments if necessary (see System Suitability under Chromatography

621

Standard solution— Prepare a solution in tetrahydrofuran having a concentration of about 2 µg per mL each of ethyl acrylate and methyl methacrylate. To 10.0 mL of this solution add 5.0 mL of a Sodium perchlorate solution, and mix. Dilute 5.0 mL of the mixture to 10.0 mL with water, and mix.

The solution contains a concentration of about 0.67 mg per mL each of ethyl acrylate and methyl methacrylate.

NF27

Test stock solution— Dissolve 1.0 g of Ethyl Acrylate and Methyl Methacrylate Copolymer Dispersion with tetrahydrofuran, and dilute with the same solvent to 50 mL.

Test solution— To 5.0 mL of Sodium perchlorate solution add 10.0 mL of the Test stock solution, dropwise, while stirring continuously. Centrifuge and filter the clear supernatant. Dilute 5.0 mL of the clear supernatant with water to 10.0 mL, and mix.

Chromatographic system (see Chromatography

621

)— The liquid chromatograph is equipped with a 200-nm detector and a 4.6- × 120-mm column that contains packing L1. The flow rate is about 2 mL per minute. Chromatograph the Standard solution, and record the peak responses as directed for Procedure: the resolution, R, between ethyl acrylate and methyl methacrylate is not less than 2.0; and the relative standard deviation for replicate injections is not more than 2.0% for each analyte.

Procedure— Separately inject equal volumes (about 50 µL) of the Standard solution and the Test solution into the chromatograph, record the chromatograms, and measure the responses for the major peaks.

Calculate the percentage of each monomer in the portion of Ethyl Acrylate and Methyl Methacrylate Copolymer Dispersion taken by the formula:

100(3)(50)(10

6)(C/W)(rU/rS)

in which 3 is the dilution factor for the preparation of the Test solution from the Test stock solution; 50 is the volume in mL of the Test stock solution; 10

6 is the conversion factor from µg to g; C is the concentration, in µg per mL, of the monomer in the Standard solution; W is the weight, in g, of Dispersion taken to prepare the Test stock solution;

NF27 and rU and rS are the peak responses for the monomer obtained from the Test solution and the Standard solution, respectively: not more than 0.01% of total monomers is found.

Coagulum content— Accurately weigh a stainless steel sieve having 125-µm openings, and filter 100 g of Ethyl Acrylate and Methyl Methacrylate Copolymer 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%).

1 A simple glass microscope slide is suitable.

2 KRS-5 consists of 42% thallium(I) bromide and 58% thallium(I) iodine by molecular weight. Suitable disks of silver chloride and of KRS-5 are available from www.photonic.saint-gobain.com, www.almazoptics.com, and www.internationalcrystal.net

Auxiliary Information— Please check for your question in the FAQs before contacting USP.

Topic/Question	Contact	Expert Committee
Monograph	Hong Wang, Ph.D. Scientist 1-301-816-8351	(EM205) Excipient Monographs 2
Reference Standards	Lili Wang, Technical Services Scientist 1-301-816-8129 RSTech@usp.org
61	Radhakrishna S Tirumalai, Ph.D. Senior Scientist 1-301-816-8339	(MSA05) Microbiology and Sterility Assurance
62	Radhakrishna S Tirumalai, Ph.D. Senior Scientist 1-301-816-8339	(MSA05) Microbiology and Sterility Assurance

USP32–NF27 Page 1233

Pharmacopeial Forum: Volume No. 33(6) Page 1247

Chromatographic Column—

ETHYL ACRYLATE AND METHYL METHACRYLATE COPOLYMER DISPERSION

Chromatographic columns text is not derived from, and not part of, USP 32 or NF 27.