RESUMEN
OBJECTIVE: To establish a method for simultaneous determination of vitamin B1, dihydralazine sulfate, vitamin B6 and vitamin B5 in Compound Apocynum venetum tablets I.METHODS: HPLC method was used for content determination of 8 batches of samples from 2 enterprises. The determination was performed on Waters XBridge C18 column with mobile phase consisted of acetonitrile-0. 2％ phosphoric acid (gradient elution) at the flow rate of 0. 5 mL/min. The detection wavelengths were set at 285 nm (vitamin Bi, dihydralazine sulfate, vitamin B6) and 210 nm (vitamin B5). The column temperature was 30 ℃, and sample size was 10 μL. RESULTS: The linear ranges of vitamin Bi, dihydralazine sulfate, vitamin B6 and vitamin B5 were 41. 66-208. 3 μg/mL (r=0. 999 9), 127. 0-635. 0 μg/mL (r=0. 999 9), 40. 74-203. 7 μg/mL (r=0. 999 9) and 22. 72-113. 6 μg/mL (r= 0. 999 9), respectively. The limits of quantitation were 0. 267, 0. 274, 0. 062, 0. 124 μg/mL, respectively. The limits of detection were 0. 095, 0. 088, 0. 021, 0. 039 μg/mL, respectively. RSDs of precision, stability and reproducibility tests were all lower than 2. 0％ (n=6). The average recoveries were 98. 70％ (RSD=0. 69％, n=9),99. 74％ (RSD=1. 2％, n=9), 99. 89％ (RSD= 1. 0％, n=9), 99. 25％ (RSD=1. 2％, n=9), respectively. Among 8 batches of samples, the contents of vitamin B1, dihydralazine sulfate, vitamin B6 and vitamin B5 were 91. 44％-98. 74％, 36. 68％-95. 23％, 92. 42％-97. 90％, 91. 36％-99. 48％ of labelled amount, respectively. The contents of dihydralazine sulfate were significantly different and differed by 2. 6 times between the lowest and the highest threshold value. CONCLUSIONS: The method is accurate, reliable, simple and can be used for simultaneous determination of the above 4 components in Compound A. venetum tablets I.