Determination of Content and Related Substances in 5-Aminosalicylic Acid Enemas by HPLC / 中国药师

ABSTRACT

Objective:To establish an HPLC method to determine 5-amino salicylic acid (5-ASA) and its related substances in the enemas. Methods:The liquid chromatograph was equipped with a Hypersil ODS C18 column (250 mm × 4. 6 mm,5. 0 μm) with gradient elution. The mobile phase A was composed of pH 7. 5 phosphate buffer ( PBS), tetrabutyl ammonium hydroxide solution (TBAH), methanol and water (600∶50∶50∶300), the mobile phase B was composed of pH 7. 5 PBS, TBAH, methanol and water (200∶50∶300∶450). The wavelength was 208nm, the column temperature was 40 ℃ and the injection volume was 20μl. Results:5-ASA and its two degradation products could be completely separated. The concentration of 5-ASA and the corresponding peak area had a good linear relationship within the range of 1-250μg·ml-1(r=0. 999 5). The average recovery was 99. 44%(RSD=0. 94%,n=9). Conclusion:The method is simple, sensitive and reproducible, and can be used in the determination of the content and related substances in the enemas.