Full factorial design for optimization, development and validation of HPLC method to determine valsartan in nanoparticles

High performance liquid chromatographic method was optimized, developed and validated as per the ICH guidelines. In this study the 20 mM ammonium formate and acetonitrile in the 57:43 ratio were used as mobile phase for the analysis of valsartan. Full factorial design was used to optimize the effect of variable factors. The responses were peak area, tailing factor and number of theoretical plates. The quadratic effect of flow rate and wavelength individually as well as in interaction were most significant (p < 0.0001 and p < 0.0086, respectively) on peak area; the quadratic effect of pH of buffer was also most significant effect (p < 0.0001) on tailing factor (5%) whereas the quadratic effect of flow rate and wavelength individually was significant (p = 0.0006 and p = 0.0265, respectively) on the number of theoretical plates. The high-performance liquid chromatographic separation was performed at the flow rate 1.0 min/mL, UV detector wavelength 250 nm and pH of the buffer 3.0 as optimized parameters using design of experiments. The retention time values of valsartan were found to be 10.177 min. Percent recovery in terms of accuracy for the prepared valsartan nanoparticles was found in the range of 98.57–100.27%.