Spectrophotometric Determination of Eflornithine Hydrochloride using Vanillin as Derivative Chromogenic Reagent

Purpose: To develop and validate a spectrophotometric method for the quantitative determination of eflornithine hydrochloride as a pure compound and in pharmaceutical formulations.
Methods: The method involved the reaction of the target compound with vanillin reagent at specific pH 5.6 to produce a green reddish color chromogen. The derivative chromogen exhibits absorption maxima at 578 nm. At the pH of the reaction, there was no degradation. The developed method was validated as per International Conference of Harmonization (ICH) guidelines with respect to specificity, linearity, limit of detection, limit of quantification, accuracy, precision and robustness.
Results: Under the indicated conditions, the proposed method was linear over the concentration range of 5 - 25 μg/ml and the correlation coefficient (r²) was > 0.998 (n = 6) with a relative standard deviation (RSD) of 1.003 % (n = 6). Mean recovery of the target compound was 100.58 % with a limit of quantification (LOQ) of 4.3 μg/ml and limit of detection (LOD) of 1.2 μg/ml.
Conclusion: The results demonstrate the stability-indicating power of the proposed method which is precise, accurate, simple and economic. Thus, the method can be applied to the routine analysis of eflornithine hydrochloride in bulk and pharmaceutical formulations.

Keywords
Eflornithine hydrochloride; Vanillin; Spectrophotometric assay; Validation; ICH guidelines