Degradation Study on Sulfasalazine and a Validated HPLC-UV Method for its Stability Testing.

Area of Science:

• Pharmaceutical Chemistry
• Analytical Chemistry

Background:

• Sulfasalazine (SSZ) is a widely used anti-inflammatory drug.
• Understanding its degradation pathways is crucial for ensuring drug product quality and stability.

Purpose of the Study:

• To investigate the degradation behavior of Sulfasalazine (SSZ) under various stress conditions.
• To develop and validate a stability-indicating RP-HPLC method for SSZ analysis.

Main Methods:

• Degradation studies were performed following ICH guidelines, including hydrolysis (acid, alkali, water), oxidation, dry heat, and photolysis.
• A stability-indicating RP-HPLC method was developed using an XTerra® RP18 column and a mobile phase of methanol and ammonium acetate buffer.
• The method was validated for linearity, precision, accuracy, and robustness.

Main Results:

• Sulfasalazine exhibited significant stability across most stress conditions, with no degradation observed except under alkaline hydrolysis.
• Alkaline hydrolysis resulted in the formation of a single minor degradation product.
• The developed RP-HPLC method demonstrated excellent linearity (r²=0.99945), precision (%RSD <2), and accuracy (94-102%).
• PDA analysis confirmed SSZ peak purity and the method's selectivity, with a resolution factor >2 from the nearest eluting peak.

Conclusions:

• Sulfasalazine is highly stable under acidic, oxidative, thermal, and photolytic stress conditions.
• A validated, stability-indicating RP-HPLC method was successfully developed for the quantitative analysis of SSZ and its degradation products.
• The method is suitable for stability testing of pharmaceutical formulations containing SSZ.