Optimized and validated RP-HPLC method for the quantification of curcumin in formulations containing Curcuma longa L. extracts

Abstract

A rapid, accurate, and precise RP-HPLC method has been established and validated for the determination of curcumin in a solid dosage form containing turmeric root dry extract. The chromatographic separation of curcumin was conducted on Rastek C18 column (150 mm × 4.6 mm i.d., 5 µm) using an isocratic elution with the mobile phase composed of acetonitrile and 1.0% (v/v) formic acid in 50:50 ratio. The detection wavelength was set at 425 nm. The separation was performed at a flow rate 1 mL/min and the column was kept at a constant 40°C. The method was validated as per International Council for Harmonization (Q2R1 ICH) guidelines. The calibration curve was linear from 33.00–100.00 ng/mL with the correlation coefficient >0.9999. Limit of detection (LOD) and limit of quantification (LOQ) were 0.97 and 2.95 ng/mL, respectively. The intra-day/inter-day accuracy and precision demonstrated a recovery of 99.33–100.51%/99.59–100.51% with a Relative Standard Deviation (RSD) of 0.09%. A tested solid dosage form containing turmeric root dry extract confirmed the applicability of the method in the quantification of curcumin in commercially available turmeric formulation. The proposed method was proven to have acceptable specificity, sensitivity and accuracy for the quantity control of curcumin in formulations containing Curcuma longa L. extracts.