ABSTRACT
OBJECTIVE: To establish a determination method of the related substances of lapatinib ditosylate tablets by HPLC. METHODS: Waters Xterra MS C18 column (4.6 mm × 250 mm, 5 μm) was selected; 0.01 mol · L-1 sodium dihydrogen phosphate solution (pH adjusted to 3.2 with phosphoric acid) was mobile phase A, acetonitrile was mobile phase B, and gradient elution was used at a flow rate of 1.0 mL · min-1. The detection wavelength was set at 265 nm, and the column temperature was 40°C. RESULTS: Lapatinib Impurity A, LAPA-2 and LAPA-1 had good linearity in the range of 0.02-8.08, 0.02-8.26 and 0.02-8.29 mg · mL-1, respectively (r≥0.9999). The limits of quantitation (LOQ) were 1.0, 1.4, and 2.1 ng, respectively. The average recovery (n=9) was in the range of 100.2%-102.9%, and RSDs (n=9) were in the range of 0.02%-0.66%. CONCLUSION: The method is simple, accurate, and specific and can quantitatively determine the related substances of lapatinib ditosylate tablets.