Sulindac 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

Sulindac Tablets contain NLT 90.0% and NMT 110.0% of the labeled amount of sulindac (C₂₀H₁₇FO₃S).

2 IDENTIFICATION

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

B. The UV-Vis spectrum of the major peak of the Sample solution corresponds to that of the Standard solution, as obtained in the Assay.

3 ASSAY

PROCEDURE

Solution A: 0.1% formic acid in water Solution B: 0.1%formic acid in acetonitrile Mobile phase: See Table 1.

Table 1

Diluent: Acetonitrile and water (50:50)

System suitability solution: 0.018 mg/mL each of USP Sulindac RS, USP Sulindac Related Compound A RS, USP Sulindac Related Compound B RS, and USP Sulindac Related Compound C RS in Diluent

Standard solution: 0.2 mg/mL of USP Sulindac RS in Diluent

Sample solution: Nominally 0.2 mg/mL of sulindac in Diluent prepared as follows. Dissolve a quantity nominally equivalent to 20 mg of sulindac from finely powdered Tablets in 70 mL of Diluent in a 100-mL volumetric flask. Shake by mechanical means for 60 min and dilute with Diluent to volume. Shake for another 5 min. Centrifuge the solution for 10 min and inject the supernatant.

Chromatographic system

(See Chromatography 〈621〉, System Suitability.)

Mode: LC

Detector: UV 330 nm. For Identification B, use a diode array detector in the range of 200–400 nm.

Column: 2.1-mm × 15-cm; 1.7-µm packing L1

Column temperature: 45°

Flow rate: 0.3 mL/min

Injection volume: 2 µL

System suitability

Samples: System suitability solution and Standard solution

[NOTE—See Table 2 for the relative retention times.]

Suitability requirements

Resolution: NLT 4.0 between sulindac and sulindac related compound A; NLT 4.0 between sulindac related compound A and sulindac related compound B, System suitability solution

Tailing factor: NMT 2.0, Standard solution

Relative standard deviation: NMT 2.0%, Standard solution Analysis

Samples: Standard solution and Sample solution

Calculate the percentage of the labeled amount of sulindac (C₂₀H₁₇FO₃S) in the portion of Tablets taken:

Result = (r_U/r_S) × (C_S/C_U) × 100

r_U = peak response from the Sample solution

r_S = peak response from the Standard solution

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

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

Acceptance criteria: 90.0%–110.0%

4 PERFORMANCE TESTS

DISSOLUTION 〈711〉

Medium: 0.1 M pH 7.2 phosphate buffer prepared as directed in Reagents, Indicators, and Solutions—Buffer Solutions, except to use twice the stated quantities of the monobasic potassium phosphate solution and of the sodium hydroxide solution; 900 mL

Apparatus 2: 50 rpm

Time: 45 min

Standard solution: 20 µg/mL of USP Sulindac RS in Medium

Sample solution: Pass 20 mL of the solution under test through a suitable filter, transfer 10 mL of the filtrate to a 100-mL volumetric flask, and dilute with Medium to volume.

Blank: Medium

Instrumental conditions

Mode: UV

Analytical wavelength: Maximum absorbance at about 326 nm

Analysis

Samples: Standard solution and Sample solution

Calculate the percentage of the labeled amount of sulindac (C₂₀H₁₇FO₃S) dissolved:

Result = (A_U/A_S) × C_S × D × V × (1/L) × 100

A_U = absorbance of the Sample solution

A_S = absorbance of the Standard solution

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

D = dilution volume

V = volume of Medium, 900 mL

L = label claim (mg/Tablet)

Tolerances: NLT 80% (Q ) of the labeled amount of sulindac (C₂₀H₁₇FO₃S) is dissolved.

UNIFORMITY OF DOSAGE UNITS 〈905〉: Meet the requirements

5 IMPURITIES

ORGANIC IMPURITIES

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

Standard solution: 0.018 mg/mL each of USP Sulindac RS, USP Sulindac Related Compound A RS, USP Sulindac Related Compound B RS, and USP Sulindac Related Compound C RS in Diluent. Sonicate for 2–5 min and mix with inversion.

Sample solution: Nominally 0.6 mg/mL of sulindac in Diluent prepared as follows. Dissolve a quantity nominally equivalent to 60 mg of sulindac from finely powdered Tablets in 70 mL of Diluent in a 100-mL volumetric flask. Shake by mechanical means for 60 min and dilute with Diluent to volume. Shake for another 5 min. Centrifuge the solution for 10 min. Collect and inject the supernatant.

System suitability

Sample: Standard solution

[NOTE—See Table 2 for the relative retention times.]

Suitability requirements

Resolution: NLT 4.0 between sulindac and sulindac related compound A; NLT 4.0 between sulindac related compound A and sulindac related compound B

Relative standard deviation: NMT 2.0% for sulindac, sulindac related compound B, and sulindac related compound C

Analysis

Samples: Standard solution and Sample solution

Calculate the percentage of sulindac related compound B or sulindac related compound C in the portion of Tablets taken:

Result = (r_U/r_S) × (C_S/C_U) × 100

r_U = peak response of sulindac related compound B or sulindac related compound C from the Sample solution

r_S = peak response of sulindac related compound B or sulindac related compound C from the Standard solution

C_S = concentration of the corresponding related compound in the Standard solution (mg/mL)

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

Calculate the percentage of any individual unspecified impurity in the portion of Tablets taken:

Result = (r_U/r_S) × (C_S/C_U) × 100

r_U = peak response of any individual unspecified impurity from the Sample solution

r_S = peak response of sulindac from the Standard solution

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

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

Acceptance criteria: See Table 2.

Table 2

^a Sulindac related compound A is controlled in the API. Therefore, no individual acceptance criteria is needed. Sulindac related compound B and sulindac related compound C are both degradants and process impurities.

6 ADDITIONAL REQUIREMENTS

PACKAGING AND STORAGE: Preserve in well-closed containers.

USP REFERENCE STANDARDS 〈11〉

USP Sulindac RS

USP Sulindac Related Compound A RS

(E)-2-{5-Fluoro-2-methyl-1-[4-(methylsulfinyl)benzylidene]-1H-inden-3-yl}acetic acid. C₂₀H₁₇FO₃S    356.41

USP Sulindac Related Compound B RS

(Z)-2-{5-Fluoro-2-methyl-1-[4-(methylsulfonyl)benzylidene]-1H-inden-3-yl}acetic acid. C₂₀H₁₇FO₄S    372.41

USP Sulindac Related Compound C RS

(Z)-2-{5-Fluoro-2-methyl-1-[4-(methylthio)benzylidene]-1H-inden-3-yl}acetic acid. C₂₀H₁₇FO₂S    340.41