Determination of Related Substances in Rifabutin Crude Drug and Capsules by HPLC / 中国药房

ABSTRACT

OBJECTIVE： To establish a method for the determination of related substances in rifabutin crude drug and capsules by HPLC. METHODS： HPLC method was adopted. The determination was performed on Agilent XDB-C8 column with mobile phase consisted of acetonitrile-0.1 mol/L potassium dihydrogen phosphate solution （pH 6.5±0.1） （50 ∶ 50， V/V） at the flow rate of 1.0 mL/min. The detection wavelength was set at 254 nm， the column temperature was 30 ℃， and sample size was 20 μL. The mobile phase was used as solvent to prepare the sample solution with a mass concentration of 1.0 mg/mL. The system suitability test was performed by using newly established method and current method （mass concentration of sample solution 0.5 mg/mL， C18 column） stated in quality standard of rifabutin crude drug and capsules. Related substance test was conducted for 6 batches of rifabutin crude drug and capsule （peak area normalization method）. RESULTS： The linear range of rifabutin was 0.8-16 μg/mL（r＝1.000 0）， RSDs of precision， reproducibility and stability tests （12 h） were all lower than 2.0％ （n＝6）； the limits of detection and quantification were 0.025 4， 0.085 2 μg/mL. In system suitability test， by using new method and current method， separation degree of rifabutin peak and pre-degradation product peak were 7.50 and 3.47. When 6 batches of samples were determined， the number of impurities detected by this method was 1-5 more than that by the current method， and the total amount of impurities was 0.19％-0.55％ higher. CONCLUSIONS： Established new method is well-separated and sensitive， and can be used for the determination of related substance in rifabutin crude drug and capsules， which helps the quality control of drugs.