Determination of the content and related substances of minodronic acid by HPLC

SONG Wei-jie; ZHOU Yue-ying; WANG Li-qiang; QIAO Feng-min; LIU Shan

Abstract：Objective: To establish a method for determination of the content and related substances of minodronic acid. Methods: HPLC method was adopted. Diamonsil C18 column ( 250 mm × 4. 6 mm, 5 μm) was used, and the mobile phase was composed of 0. 01 mol·L-1 sodium pyrophosphate solution and 0. 001 mol·L-1 tetrabutylammonium bromide solution ( p H adjusted to 6. 5 by phosphoric acid) -methanol ( 95∶ 5) at the flow rate of1. 0 m L·min-1. The column temperature was 25 ℃, and the injection volume was 20 μL. The detection wavelength of related substances of minodronic acid was 220 nm and the content was 280 nm. Results: Minodronic acid and all the related compounds could be well separated. The calibration curves were linear in appropriate concentration ranges, and the recovery of the compounds were between 98. 0％～ 102. 0％ ( RSD ＜ 2. 0％). The contents of total related substances of 3 batches of samples were 0. 23％, 0. 24％ and 0. 25％, respectively, and the contents of minodronic acid were 99. 72％, 99. 45％ and 99. 51％, respectively. Conclusion: The method is specific and accurate, which can be applied in the determination of the content and related substances of minodronic acid, and it can provide a theoretical basis for the following quality control research of minodronic acid products.