A validated HPLC assay method for the determination of sodium alginate in pharmaceutical formulations.

A high-performance liquid chromatography-diode array detector method was developed and validated for the quantification of sodium alginate in antacid oral suspension using a phenyl stationary phase and buffer solution at pH 7.0 as a mobile phase. The method was validated for specificity, linearity, range, accuracy, precision and robustness. The method was specific for the determination of sodium alginate in the bulk drug, pharmaceutical dosage form and under stress degradation. The method was linear over the range of 600 to 1,400 µg/mL with r(2) = 0.9999, and accuracy and precision were acceptable with relative standard deviation < 2.0%. The described method is simple, specific, precise, accurate, robust and stability-indicating, and can be successfully applied for the routine analysis of sodium alginate in bulk drug and pharmaceutical dosage form.