mobile phase stability and degradation studies.

The analysis was performed using mobile phase of acetonitrile and 25mM of phosphate buffer (pH 6.5) at 85:15 ratios and detection was carried out at 418 nm. The optimized conditions showed good peak resolution of curcumin with retention time of 4.5 min of standard and drug loaded nanoparticle. The limit of detection (LOD) and limit of quantitation (LOQ) was found to be 3.5 ng/mL and 12.7 ng/mL respectively. The calibration coefficient was equal to 0.9998 in the range of 25 ng/mL to 300 ng/mL indicating good linearity. The interday and intraday variability and perecentage relative standard daviation (RSD) showed variation of less than 1 in accuracy and precision indicating more accurate and precise method. The samples were also found to be stable for 7 days in mobile phase solution at ambient laboratory temperature and refrigerated temperature with precentage error of less than 0.01%. The presence of polymers and other components did not affect the results. So developed and validated RP-UFLC method can be used for the quantitative and qualitative estimation of curcumin in the nanoformulations as well as other pharmaceutical formulations.