Development and Validation of a RP-HPLC–PDA Method for Determination of Curcuminoids in Microemulsions

A sensitive, specific and rapid high-performance liquid chromatography method was developed in an effort to quantify extremely low curcuminoid levels for the future transdermal experiments where the curcuminoids are incorporated with excipients such as microemulsion, liposomes, and micelles. The chromatographic separation was performed using a Symmetry®C₁₈, 250 × 4.6 mm, 5-μm column, with a mobile phase composed of 5 mM acetonitrile:phosphoric acid (45:55, v/v) at a flow rate of 1.0 mL min⁻¹, it was sensitive with a low limit of quantitation for curcuminoids (0.626 ng mL⁻¹for curcumin) and good linearity (r² ≥ 0.999) over the range 1–100 ng mL⁻¹. All the validation data, such as accuracy and precision, were within the required limits from the ICH guideline. The assay method was successfully applied during forced degradation of curcuminoid solutions. The method retained its accuracy and precision when the standard addition technique was applied.