Development of UV spectrophotometric method for estimation of curcumin in bulk drug and nanogel formulation: A hydrolytic degradation studies

The main purpose of this research was to develop and validate a cost effective UV spectrophotometric method for determination of curcumin in bulk drug and nanogel formulation. The method was validated according to the guideline of International Conference on Harmonisation (ICH). The curcumin was found to be soluble in methanol with λmax of 425 nm. Curcumin over the concentration level of (1-8 µg mL) depicted linear relation in the plot of concentration vs. absorbance. The regression equation of graph was y = 0.1137x - 0.0138 with R value of 0.999. The limits of detection and quantification were 0.23 μg mLand 0.75 μg mL, respectively. The method was accurate, precise, reproducible and robust since all the samples analyzed had relative standard deviation less than 2%. No statistically significant difference between theoretical and measured concentrations was detected. The degradation kinetics of free curcumin (k = 0.042 µg mL.h, 0.53 µg mL.h and 0.068 µg mL.h) and nanogel formulation (k = 0.178 h, 0.003 h and 0.005 h) were zero and first order, respectively. The proposed method was found to be specific while estimating curcumin loaded nanogel formulation without interference of excipients. The developed method was cost effective and can be used for routine quality control analysis of curcumin.