Sulfasalazine 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)

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1 DEFINITION

Sulfasalazine Delayed-Release Tablets contain NLT 95.0% and NMT 105.0% of the labeled amount of sulfasalazine (C₁₈H₁₄N₄O₅S).

2 IDENTIFICATION

A.

Standard solution and Sample solution: Proceed as directed in the Assay.

Acceptance criteria: The visible absorption spectrum of the Sample solution corresponds to that of the Standard solution, as prepared in the Assay.

3 ASSAY

PROCEDURE

Standard solution: 7.5 µg/mL of USP Sulfasalazine RS in the same medium as the Sample solution

Sample stock solution: Nominally 1.5 mg/mL of sulfasalazine prepared as follows. Dissolve an appropriate amount of sulfasalazine from finely powdered Tablets (NLT 20) in 0.1 N sodium hydroxide in a suitable volumetric flask.

Sample solution: Nominally 7.5 µg/mL of sulfasalazine prepared as follows. Transfer 5.0 mL of the Sample stock solution to a 1000-mL volumetric flask containing 750 mL of water. Mix, add 20.0 mL of 0.1 N acetic acid, and dilute with water to volume.

Instrumental conditions

(See Ultraviolet-Visible Spectroscopy 〈857〉.) Mode: UV

Analytical wavelength: Maximum at about 359 nm Blank: Water

Analysis

Samples: Standard solution, Sample solution, and Blank Concomitantly determine the absorbances of the Samples.

Calculate the percentage of the labeled amount of sulfasalazine (C₁₈H₁₄N₄O₅S) in the portion of Tablets taken:

Result = (A_U/A_S) × (C_S/C_U) × 100

A_U = absorbance of the Sample solution

A_S = absorbance of the Standard solution

C_S = concentration of USP Sulfasalazine RS in the Standard solution (µg/mL)

C_U = nominal concentration of sulfasalazine in the Sample solution (µg/mL)

Acceptance criteria: 95.0%–105.0%

4 PERFORMANCE TESTS

DISSOLUTION 〈711〉: Proceed as directed in the Procedure for Method B in Apparatus 1 and Apparatus 2, Delayed-Release Dosage Forms. Acid stage

Medium: 0.1 N hydrochloric acid; 900 mL

Apparatus 1: 100 rpm

Time: 120 min

At the end of 120 min, determine the amount of sulfasalazine (C₁₈H₁₄N₄O₅S) dissolved by using the following method. Mobile phase: Isopropanol, acetonitrile, water, and glacial acetic acid (11:7:22:0.4)

Standard solution: 55.6 µg/mL of USP Sulfasalazine RS in 0.1 N sodium hydroxide

Sample solution: Pass about 7 mL of the solution under test through a membrane filter of 0.45-µm pore size.

Chromatographic system

(See Chromatography 〈621〉, System Suitability.) Mode: LC

Detector: UV 254 nm

Column: 4.6-mm × 25-cm; 5-µm packing L1 Flow rate: 1 mL/min

Injection volume: 10 µL System suitability

Sample: Standard solution

[NOTE—The retention time for sulfasalazine is about 7.7 min.] Suitability requirements

Relative standard deviation: NMT 2.0% Analysis

Samples: Standard solution and Sample solution

Calculate the percentage of sulfasalazine (C H N O S) dissolved:

Result = (r_U/r_S) × (C_S/L) × V × 100

r_U = peak response from the Sample solution

r_S = peak response from the Standard solution

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

L = label claim (mg/Tablet)

V = volume of Medium, 900 mL

Tolerances: NMT 10% of the labeled amount of sulfasalazine (C₁₈H₁₄N₄O₅S) is dissolved. Buffer stage

Medium: pH 7.5 phosphate buffer; 900 mL

Apparatus 1: 100 rpm

Time: 60 min

At the end of 60 min, determine the amount of sulfasalazine (C₁₈H₁₄N₄O₅S) dissolved by using the chromatographic method as described in Acid stage.

Tolerances: NLT 85% (Q ) of the labeled amount of sulfasalazine (C₁₈H₁₄N₄O₅S) is dissolved.

UNIFORMITY OF DOSAGE UNITS 〈905〉: Meet the requirements

5 ADDITIONAL REQUIREMENTS

PACKAGING AND STORAGE: Preserve in well-closed containers.

USP REFERENCE STANDARDS 〈11〉

USP Sulfasalazine RS