Analysis of Tolfenamic Acid using a Simple, Rapid, and Stability-indicating Validated HPLC Method.

Area of Science:

• Analytical Chemistry
• Pharmaceutical Analysis

Background:

• Tolfenamic acid (TA) is a nonsteroidal anti-inflammatory drug (NSAID) from the fenamate class.
• A validated stability-indicating method for TA assay is currently lacking.

Purpose of the Study:

• Develop a simple, rapid, accurate, precise, economical, and robust RP-HPLC method for TA determination.
• Validate the method for assaying TA in pure and tablet dosage forms.

Main Methods:

• RP-HPLC method development and validation per ICH guidelines.
• Forced degradation studies (stress testing) and purity assessments using TLC and FTIR.
• Robustness testing via Plackett-Burman experimental design.
• Analysis using a C18 column with acetonitrile/water mobile phase (pH 2.5) and UV detection at 280 nm.

Main Results:

• The method demonstrated high accuracy (99.39-100.80%) and precision (<1.5% RSD).
• Robustness was confirmed (<2% RSD), with results statistically comparable to the British Pharmacopoeia method.
• The method exhibited superior sensitivity and specificity, unaffected by stress degradation.

Conclusions:

• The developed RP-HPLC method is accurate, precise, and robust for TA assay.
• The method is suitable for quality control of TA in both bulk drug and tablet formulations.
• Stress degradation studies confirmed the method's specificity and accuracy.