Development of Analytical Method for Estimation of Curcumin Demethoxy Curcumin and Bis Demethoxy Curcumin from Fast Dissolving Tablet Containing Curcuma Extract

Abstract

Curcumin, demethoxy curcumin and bis-demethoxy curcumin were isolated from the dried root powder of Curcuma longa through the combined application of flash chromatography and open column chromatography. Isolated constituents were identified using spectral methods. An analytical method was developed for simultaneous quantitative estimation of curcuminoids from fast dissolving tablets containing ethanolic extract of Curcuma sp., as an active ingredient. The separation was achieved in a C18 column using an isocratic mobile phase comprised of acetonitrile:water (aqueous phase containing 4 % v/v glacial acetic acid) (50:50 % v/v), with the flow rate set at 2.0 ml/min. The chromatogram was recorded at 425 nm, using a photodiode array detector. The developed analytical method was validated as per international conference on harmonisation guidelines. The developed analytical method was found to be linear in the concentration range of 5-120 μg/ml, precise and robust to minor modifications in selected chromatographic parameters. The average of recovery was found within the range of 98 %-102 %. Limit of detection and limit of quantification value for curcumin was determined to be 0.35 and 1.06, respectively. The tablets containing 100 mg Curcuma ethanolic extract were formulated using the directly compressible vehicle. Each tablet was found to contain 20.77 %±0.22 % w/w curcumin, 3.18 %±0.03 % w/w demethoxy curcumin and 0.33 %±0.006 % w/w bis-demethoxy curcumin when estimated using developed analytical method.