RESUMEN
Objective To establish a method for the determination of 6 isomers of silibin in silymarin Capsules.Method The RP-HPLC method was applied.Separation and determination of silibinin was performed on a C18 column(125 mm? 4.0 mm) with the flow rate of 0.8 mL/min,temperature at 25 ℃ and detection wavelength at 288 nm.The mixed solvent of A(85 % phosphoric acid ∶ methnol ∶ water=5 ∶ 35 ∶ 65) and B(85 % phosphoric acid ∶ methnol ∶ water=5 ∶ 50 ∶ 50) served as the mobile phase(gradient elution).Results A good linearity of silibinin was in the rang of 0.508 8～ 2.544 0 ? g(r=0.999 8).The average recovery was 99.5 % and RSD was 2.2 %(n=5).Conclusion With silibinin as as the control,this method is simple and accurate and can be used for the determination of six isomers of silibin and can be used for quality control of Silymarin Capsules.