Objective: The main objective of this research work is to develop and validate a single reverse-phase high-performance liquid chromatography (RP-HPLC) method. This method should becapable of quantifying all the known, as well as other possible degradation impurities of sodium nitroprusside (SNP) in its injection formulation.
Methods: Of allmethod development trails, we have observed better separations between known and degradation impuritiesin Inert sustain C18, (250 x 4.6) mm, 5 µm column at 30 °C temperature. Isocratic elution was carried out by using pH 8.6 phosphate buffer and acetonitrile in the ratio of 65:35 %v/v with a flow rate of 0.8 ml/min. The detection was carried out at 220 nm, with an injection volume of 10 µl.
Results: In the proposed method, SNP was eluted at 22.5 min. Nitrite, nitrate, and ferrocyanide were linear from 0.25 to 37 μg/ml, ferricyanide was linear from 1.0 to 37 μg/ml, and SNP was linear from 0.75 to 37 μg/ml. The % RSD for six spiked samples (precision)was found to be less than 0.5 %. Accuracy was performed for known impurities from LOQ to 150 % for a 0.5 % specification level. The resultswere found to be in the acceptance range of 90-110 %. The LOQ concentration of nitrite, nitrate, and ferrocyanide was 0.25 μg/ml each,LOQ offerricyanide and SNP was found to be 1.0 μg/ml and 0.75 μg/ml, respectively. The SNP injection samples were exposed to different degradation conditions, and the results were found specific in the proposed methodology.
Conclusion: The proposed RP-HPLC method is specific, precise, accurate, linear, stable, and robust for quantification of known and other possible degradation impurities in SNP injection formulation.
Impurity Profiling of Baclofen Using Gradient HPLC–UV Method
