Abstract: Objective: To establish a method for the determination of related substances in hydrocortisone butyrate cream. Methods:
Kromasil XDB-C18（ 4.6 mm×250 mm, 5 μm） column was used for gradient elution with acetonitrile-0.5% glacial acetic acid solution as
the mobile phase. Detection was performed at a wavelength of 254 nm, and methodological validation was performed on the established
method. Results: Hydrocortisone butyrate was well separated from all impurities and had good linear relationship in the range of 0.05~
7.50 μg/mL. In all samples, hydrocortisone 21-butyrate was the highest single impurity, and the contents of hydrocortisone and other
unknown impurities were less than 0.26%, and the total impurities ranged from 0.37% to 2.72%. Under the condition of oxidation, high
temperature and strong light, hydrocortisone butyrate cream had good stability, and the impurity content did not increase significantly.
Under the condition of strong acid and strong base, hydrocortisone butyrate was easily degraded to produce hydrocortisone 21-butyrate.
Conclusion: The method established in this study has the advantages of good specificity, high sensitivity and low cost, which can
provide an important reference for the quality control of hydrocortisone butyrate cream.

Key words: hydrocortisone butyrate cream, hydrocortisone, hydrocortisone 21-butyrate, quality control, destructive test