Methacrylic Acid and Ethyl Acrylate Copolymer
(Title for this new monographto become official December 1, 2015)
(Prior to December 1, 2015, the current practice of labeling the article of commerce with the name Methacrylic Acid Copolymer, Type C, may be continued. Use of the name Methacrylic Acid and Ethyl Acrylate Copolymer will be permitted as of December 1, 2010, but the use of this name will not be mandatory until December 1, 2015. The 60-month extension will provide the time needed by manufacturers and users to make necessary changes.)
Poly(methacrylic acid, ethyl acrylate);
Methacrylic acidethyl acrylate copolymer [25212-88-8].
Methacrylic Acid and Ethyl Acrylate Copolymer consists of methacrylic acid and ethyl acrylate monomers arranged in a random distribution. Methacrylic acid units in Methacrylic Acid and Ethyl Acrylate Copolymer are NLT 46.0% and NMT 50.6%, calculated on the dried basis. It may contain suitable surface-active agents.
• A. Infrared Absorption 197K
Use USP Methacrylic Acid and Ethyl Acrylate Copolymer (1:1) RS for Methacrylic Acid and Ethyl Acrylate Copolymer having a range of 46.0%50.6% for methacrylic acid units.
• B. It meets the requirements of the Assay.
Sample: 1 g, previously dried
Analysis: Dissolve the Sample in 100 mL of neutralized acetone, and titrate with 0.1 N sodium hydroxide VS, determining the endpoint potentiometrically (see Titrimetry 541). Each mL of 0.1 N sodium hydroxide is equivalent to 8.609 mg of methacrylic acid (C4H6O2) units.
Acceptance criteria: 46.0%50.6% for Methacrylic Acid and Ethyl Acrylate Copolymer on the dried basis
• Procedure: Limit of Methacrylic Acid and Ethyl Acrylate
Sodium perchlorate solution: 35 mg/mL of sodium perchlorate. This solution has a concentration of 0.25 M.
Mobile phase: Add phosphoric acid dropwise to water to obtain a solution having a pH of 2.0. Prepare a mixture of this acidified water and methanol (80:20) and degas.
Standard solution: Dissolve 0.01 g of methacrylic acid and 0.01 g of ethyl acrylate in 5 mL of butanol and add methanol to exactly 100 mL. Transfer 1.0 mL of this solution to a 100-mL volumetric flask. Dilute with methanol to volume. Mix 5.0 mL of this solution with 5.0 mL of Sodium perchlorate solution. This solution contains about 0.5 µg/mL each of methacrylic acid and ethyl acrylate.
Sample solution: Transfer about 3 g of Methacrylic Acid and Ethyl Acrylate Copolymer to a 50-mL volumetric flask, dilute with methanol to volume, and mix. Add 5 mL of this solution dropwise, while continuously stirring, to a beaker that contains 5.0 mL of Sodium perchlorate solution. Remove the precipitated polymer to obtain a clear supernatant by centrifugation (e.g. NLT 5000 × g for NLT 5 min). Use the clear supernatant.
Detector: UV 202 nm
Column: 4.0-mm × 12.5-cm analytical column; 7-µm packing L1
Flow rate: 2 mL/min
Injection size: 20 µL
Sample: Standard solution
[NoteThe relative retention times for methacrylic acid and ethyl acrylate are 1.0 and 2.6, respectively. ]
Resolution: NLT 2.0 between methacrylic acid and ethyl acrylate
Relative standard deviation: NMT 5.0%
Samples: Standard solution and Sample solution
Calculate the percentage of each monomer (methacrylic acid or ethyl acrylate) in the portion of Methacrylic Acid and Ethyl Acrylate Copolymer taken:
Result = (rU/rS) × (C/W) × VF × D × F × 100
Acceptance criteria: NMT 0.01% for the total amount of monomers
• Viscosity 911
Analysis: Place 254.6 g of isopropyl alcohol and 7.9 g of water in a test flask. Add a quantity of Methacrylic Acid and Ethyl Acrylate Copolymer, equivalent to 37.5 g of solids on the dried basis, while stirring by means of a magnetic stirrer. Close the flask, and continue stirring until the polymer has dissolved completely. Adjust the temperature to 20 ± 0.1. Equip a rotational viscometer with an accessory.1 The shear rate under the test condition is NLT 1 s1 and NMT 100 s 1. Follow the instrument manufacturer's directions to measure the apparent viscosity.
Acceptance criteria: 100200 mPa·s for Methacrylic Acid and Ethyl Acrylate Copolymer, with a range of 46.0%50.6% for methacrylic acid units
• Loss on Drying 731: Dry a sample at 110 for 6 h: it loses NMT 5.0% of its weight.
• Packaging and Storage: Preserve in tight containers, and store at controlled room temperature.
• Labeling: Label it to indicate the range of methacrylic acid units. The labeling also indicates the name and quantity of any added surface-active agent.
• USP Reference Standards 11
USP Methacrylic Acid and Ethyl Acrylate Copolymer (1:1) RS
USP Methacrylic Acid Copolymer, Type C RS.
1 A suitable accessory is available from Brookfield Engineering as the LV1 spindle, a cylindrical spindle 1.9 cm in diameter and 6.5 cm high attached to a shaft 0.3 cm in diameter. The spindle rotates at 30 rpm at an immersion depth of 8.15 cm.
Auxiliary Information Please check for your question in the FAQs before contacting USP.
USP35NF30 Page 1862Pharmacopeial Forum: Volume No. 35(4) Page 907