"RP-HPLC Method Development and Validation for Estimation of Naftidrofuryl Oxalate Using Box- Behnken Design"

A simple, rapid, precise, sensitive, economical, robust and QbD based RP -HPLC method has been developed for Naftidrofuryl oxalate and validated as per ICH guidelines. The response surface methodology employed with a 3-factor, 3- level Box-Behnken statistical design and used to facilitate method development and optimization. The response surface methodology and multiple response optimizations utilizing a polynomial equation were used to select suitable mobile phase combination. The independent variables studied were the Organic phase (X 1 ), Aqueous phase(X2) and (X 3 ) and the responses was Retention time (Y 1 ), Resolution (Y 2 ) and Tailing factor (Y 3 ). Chromatographic separation was achieved on Zodiac C18 column (100mm×4.6, 3µm),using optimized mobile phase Acetonitrile and pH-7 Tetrabutyl-ammonium buffer solution (90:10), at 282nm. The flow rate and injection volume were 1.0 mL-1 min and 20 µL, respectively. Analysis of variance (ANOVA) confirmed that the three factors were significant. The method was validated for linearity, system suitability, recovery (accuracy), precision, robustness, ruggedness, limit of quantitation (LOD) and detection (LOQ) as per the ICH guidelines. The precision, ruggedness and robustness values were also within the prescribed limits. Calibrations curves were linear (r2= 0.997) at the concentration range of 10 to 50μg/mL. LOD and LOQ values were 12.914µg/mL and 39.132µg/mL respectively. The proposed method was successfully developed by applying QBD based concept and proposed method can be used for routine analysis of Naftidrofuryl oxalate in quality control laboratories.