HPLC determination of berberine in medicinal herbs and a related traditional Chinese medicine

A HPLC method was developed for the determination and identification of the berberine content in Coptidis Radix, Phellodendri Cortex and a related commercially prepared traditional Chinese medicine, Huang-Lian-Jiee-Dwu-Tang. Berberine was separated by a phenyl-bound column with two kinds of mobile phases of acetonitrile: methanol: 20mM phosphate (35:20:45, v/v/v) and acetonitrile:20mM phosphate (30:70, v/v) for single herb and herbal preparation, respectively. Both mobile phases were adjusted to pH 3.0 with H3PO4 and doped with 0.1 mM 1-octanesulfonic acid. A flow rate of 1 mL/min was used. The UV detection was set at 346 nm. In both HPLC systems, intra-assay and inter-assay of accuracy and precision of berberine were less than 10% in the concentration ranges of 0.5-50 mug/mL. Various optimisations were performed to examine the berberine content in herbal medicines and their preparation including retention time, spike authentic standard, change of wavelength, change of mobile phase composition and blank test. Our results indicate that the berberine content in herbal preparation, Huang-Lian-Jiee-Dwu-Tang (8.15 +/- 0.39 mg/g) was less than that in single herb Coptidis Radix (53.63 +/- 2.45 mg/g) but higher than that in Phellodendri Cortex (3.02 +/- 0.22 mg/g) when extracted with water, which suggests that herbal matrix effects were involved in the multiple compositions of the herbal preparation, which provides some valuable information for the clinical application of herbal medicines.