An HPLC method for simultaneous quantitative determination of robinin and its aglycone kaempferol in MCF-7 human breast carcinoma cell line was developed. Robinin and kaempferol were separated using a Platinum EPS C-18 column (4.6 × 250 nm, 5 μm particle size). The detector was set at 380 nm. The mobile phase consisted of solution A [5 % MeOH in phosphate buffer (0.01 M, pH 2.0)] and solution B (THF:i-PrOH:MeOH:H2O, 150:200:67.5:32.5) in a 60:40 ratio (A:B). Calibration curves for both compounds were linear (R 2 = 0.9997, R 2 = 1) in the concentration range 25 – 1000 ng/mL. The intra- and interday variation coefficients were 1.31 – 8.92 %. The mean recoveries were 97.3 – 104.6 %. Robinin, a flavonoid glycoside isolated from leaves and flowers of Astragalus falcatus, decreases residual nitrogen, creatine, and urea in blood. The finished tablet dosage form prepared from it, flaronin, is used to treat uremia caused by chronic kidney failure.