Stability indicating HPLC-UV method for detection of curcumin in Curcuma longa extract and emulsion formulation

A stability-indicating HPLC-UV method for the determination of curcumin in Curcuma longa extract and emulsion was developed. The system suitability parameters, theoretical plates (N), tailing factor (T), capacity factor (K'), height equivalent of a theoretical plate (H) and resolution (Rs) were calculated. Stress degradation studies (acid, base, oxidation, heat and UV light) of curcumin were performed in emulsion. It was found that N > 6500, T < 1.1, K' was 2.68-3.75, HETP about 37 and Rs was 1.8. The method was linear from 2 to 200 mu g/mL with a correlation coefficient of 0.9998. The intra-day precision and accuracy for curcumin were <= 0.87% and <= 2.0%, while the inter-day precision and accuracy values were <= 2.1% and <=-1.92. Curcumin degraded in emulsion under acid, alkali and UV light. In conclusion, the stability-indicating method could be employed to determine curcumin in bulk and emulsions. (C) 2014 Elsevier Ltd. All rights reserved.