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 (K0), 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, K0 was 2.68–3.75, HETP about 37 and Rs was 1.8. The method was linear
from 2 to 200 lg/mL with a correlation coefficient of 0.9998. The intra-day precision and accuracy for
curcumin were 60.87% and 62.0%, while the inter-day precision and accuracy values were 62.1% and
61.92. 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.