Sulfasalazine 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 Tablets contain NLT 95.0% and NMT 105.0% of the labeled quantity of sulfasalazine (C₁₈H₁₄N₄O₅S).

2 IDENTIFICATION

PROCEDURE

Standard solution: Use the Standard solution, prepared as directed in the Assay. Sample solution: Use the Sample solution, prepared 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

Sample stock solution: 1.5 mg/mL of sulfasalazine, from finely powdered Tablets (NLT 20 tablets), in 0.1 N sodium hydroxide

Sample solution: Transfer 5.0 mL of 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.

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

Spectrometric conditions

(See Ultraviolet-Visible Spectroscopy 〈857〉.)

Mode: UV-Vis

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 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〉

Medium: pH 7.5 Phosphate Buffer (see Reagents, Indicators, and Solutions—Buffer Solutions); 900 mL

Apparatus 1: 100 rpm

Time: 60 min

Detector: UV 358 nm

Standard solution: USP Sulfasalazine RS in Medium

Sample solution: Pass a portion of the solution under test through a suitable filter. Dilute with Medium, if necessary, to a concentration that is similar to the Standard solution.

Tolerances: NLT 85% (Q) of the labeled amount of 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