Development and Validation of a HPLC–PDA Method for the Simultaneous Determination of Berberine, Palmatine, Geniposide, and Paeoniflorin in Haedoksamul-tang

Haedoksamul-tang (HST) is a traditional medical prescription comprising eight medicinal herbs: Angelica gigas, Cnidium officinale, Coptis japonica, Gardenia jasminoides, Paeonia lactiflora, Phellodendron amurense, Rehmannia glutinosa, and Scutellaria baicalensis. HST is used to treat blood circulation disorders and has anti-inflammatory, hemostatic, and anticonvulsant effects. In this study, a high-performance liquid chromatography/photodiode array detector (HPLC–PDA) method was developed and validated for the simultaneous determination of four marker compounds in HST, namely, berberine, palmatine, geniposide, and paeoniflorin. Four standard solutions and HST sample solutions were analyzed using a reverse-phase SunFire®C18 column (4.6 × 250 mm, 5 μm) using a 0.05% aqueous formic acid/methanol gradient. The column temperature, flow rate, injection volume, and wavelengths used were 28 ± 2 ℃, 1.0 mL/min, 10.0 μL, and 230 nm and 240 nm, respectively. Calibration curves of the four marker compounds showed good linearity (r2 ≥ 0.9994), and limits of detection (LODs) and quantification (LOQs) were in the ranges 0.131–0.296 μg/mL and 0.398–0.898 μg/mL, respectively. Ranges of intra- and inter-day precisions and accuracies values were 96.74–102.53% and 97.95–100.83%, respectively, and relative standard deviation (RSD) values were all <4%. Recoveries averaged 92.33–116.72% with RSD values <5%. Quantitative analysis for the four marker compounds showed geniposide (10.77 mg/g) was most abundant in HST.