Naproxen Delayed-Release Tablets

This article is compiled based on the United States Pharmacopeia (USP) – 2025 Edition

Issued and maintained by the United States Pharmacopeial Convention (USP)

DOWNLOAD PDF HERE

1 DEFINITION

Naproxen Delayed-Release Tablets contain NLT 90.0% and NMT 110.0% of the labeled amount of naproxen (C₁₄H₁₄O₃)

2 IDENTIFICATION

A. SPECTROSCOPIC IDENTIFICATION TESTS (197), Ultraviolet-Visible Spectroscopy: 197U

Standard solution and Sample solution: Prepare as directed in the Buffer stage of the Dissolution test.

Acceptance criteria: Meet the requirements

B. The retention time of the major peak of the Sample solution corresponds to that of the Standard solution, as obtained in the Assay.

3 ASSAY

PROCEDURE

Mobile phase: Acetonitrile and 1% acetic acid solution (900:1100). Filter and degas.

Diluent A: Acetonitrile and water (9:1)

Diluent B: Acetonitrile and water (1:1)

Standard stock solution: 0.5 mg/mL of USP Naproxen RS in Diluent A

Standard solution: 0.1 mg/mL of USP Naproxen RS in Mobile phase from the Standard stock solution

Sample solution: Transfer an amount nominally equivalent to 250 mg of naproxen from 20 powdered Tablets into a 100-mL volumetric flask, and add about 70 mL of Diluent B. Shake by mechanical means for 15 min, sonicate for 15 min, dilute with Diluent B to volume, and mix. Pass this solution through a suitable filter of 0.45-µm pore size. Transfer 2.0 mL of the filtrate into a 50-mL volumetric flask, and dilute with Mobile phase to volume.

Chromatographic system

(See Chromatography (621), System Suitability.)

Mode: LC

Detector: UV 254 nm

Column: 4.6-mm x 25-cm; 5-um packing L1

Flow rate: 1.0 mL/min

Injection volume: 50 µL

System suitability

Sample: Standard solution

Suitability requirements

Tailing factor: NMT 1.5

Relative standard deviation: NMT 2.0%

Analysis

Samples: Standard solution and Sample solution

Calculate the percentage of the labeled amount of naproxen (C₁₄H₁₄O₃) in the portion of Tablets taken:

                         Result = (r_U/r_S) × (C_S/C_U) × 100

r_U = peak response of naproxen from the Sample solution

r_S = peak response of naproxen from the Standard solution

C_S = concentration of USP Naproxen RS in the Standard solution (mg/mL)

C_U = nominal concentration of naproxen in the Sample solution (mg/mL)

Acceptance criteria: 90.0%-110.0%

Change to read:

4 PERFORMANCE TESTS

4.1 DISSOLUTION, Delayed-Release Dosage Forms. Method B (711)

4.1.1 Acid stage

Medium: 0.1 N hydrochloric acid; 1000 mL

Apparatus 2: 50 rpm

Time: 2 h

Standard solution: A known concentration of USP Naproxen RS in Medium

Sample solution: Pass a portion of the solution under test through a suitable filter. Dilute with Medium if necessary.

Analysis: Determine the amount of naproxen (C₁₄H₁₄O₃) dissolved by UV absorption at the wavelength of maximum absorbance at about 332 nm with the Sample solution in comparison with the Standard solution.

Tolerances: NMT 10% (Q) of the labeled amount of naproxen (C₁₄H₁₄O₃) is dissolved.

4.1.2 Buffer stage

Buffer: 0.2 M phosphate buffer, pH 6.8

Medium: Buffer, 1000 mL

Apparatus 2: 50 rpm

Time: 45 min

Standard solution: A known concentration of USP Naproxen RS in Medium

Sample solution: Pass a portion of the solution under test through a suitable filter. Dilute with Medium if necessary.

Analysis: Determine the amount of naproxen (C₁₄H₁₄O₃) dissolved by UV absorption at the wavelength of maximum absorbance at about 332 nm with the Sample solution in comparison with the Standard solution.

Tolerances: NLT 80% (Q) of the labeled amount of naproxen (C₁₄H₁₄O₃) is dissolved.

Change to read:

4.2 UNIFORMITY OF DOSAGE UNITS (905)

^▲Meet the requirements _{▲(CN 1-Aug-2023)}

Procedure for content uniformity

Mobile phase, Diluent A, Diluent B, Chromatographic system, and System suitability: Proceed as directed in the Assay.

Standard stock solution: 0.25 mg/mL of USP Naproxen RS in Diluent A

Standard solution: 0.1 mg/mL of USP Naproxen RS in Diluent B from Standard stock solution

Sample solution: Transfer 1 Tablet to a 200-mL volumetric flask, and add 140 mL of Diluent B. Shake by mechanical means for 15 min, sonicate for 15 min, and dilute with Diluent B to volume. Pass a portion of this solution through a suitable filter of 0.45-µm pore size, pipet 2.0 mL of the filtrate for a 500-mg tablet and 2.5 mL for a 375-mg tablet into a 50-ml volumetric flask, and dilute with Mobile phase to volume.

^▲_{▲(CN 1-Aug-2023)}

5 ADDITIONAL REQUIREMENTS

PACKAGING AND STORAGE: Preserve in well-closed containers, and store at controlled room temperature.

USP REFERENCE STANDARDS (11)

USP Naproxen RS