建立了高效液相色谱法测定二丙酸倍他米松(1)中的有关物质,即倍他米松(2)、倍他米松17-丙酸酯(3)、二丙酸倍氯米松(4)、6α-溴倍他米松二丙酸酯(5)。色谱柱选用COSMOSIL 5C18-MS-Ⅱ(4.6 mm×150 mm,5 μm),以0.04%三氟乙酸-H₂O为流动相A、0.02%三氟乙酸-乙腈为流动相B,梯度洗脱;流速为0.8 mL/min,检测波长为254 nm,柱温40℃。结果显示,1和杂质2~5均分离良好,且在各自浓度范围内线性关系良好;2~5的平均回收率(n=9)为99.8%~104.2%,RSD为4.0%~6.1%。1、2、4的检测限为0.1 μg/mL,3和5的检测限为0.2 μg/mL。建立的方法准确性好、灵敏度高,各组分分离较好,可用于1中有关物质的测定。

An HPLC method is established for the determination of the related substances such as betamethasone,betamethasone-17-propionate,beclomethasone dipropionate and 6-α-bromo-betamethasone dipropionate in betamethasone dipropionate.COSMOSIL 5C18-MS-Ⅱ column (4.6 mm×150 mm,5 μm) is used in the gradient elution mode,with 0.04% trifluoroacetic acid-H₂O as mobile phase A and 0.02% trifluoroacetic acid-acetonitrile as mobile phase B.The flow rate is 0.8 mL·min^-1,the wavelength used for detection is 254 nm,and the column temperature is maintained at 40℃.It is shown by the result that betamethasone dipropionate is separated well with the related four substances,and the peaks of the related substances show linear in their corresponding concentration ranges.The average recoveries (n=9) of betamethasone,betamethasone-17-propionate,beclomethasone dipropionate and 6-α-bromo-betamethasone dipropionate are in the range of 99.8%-104.2%,with RSDs of 4.0%-6.1%.The detection limits are 0.1 μg·mL^-1 for betamethasone dipropionate,betamethasone and beclomethasone dipropionate,and 0.2 μg·mL^-1 for betamethasone-17-propionate and 6-α-bromo-betamethasone dipropionate.The established method has good accuracy and high sensitivity as well as good separation effect for each component,which can be used for the determination of the related substances in betamethasone dipropionate.

唐玲玲(1989-),女,硕士,工程师,研究方向为药物分析,ll＿tang@126.com;陶永新(1971-),男,博士,教授,研究方向为药物分析,通讯联系人,taoyx@cczu.edu.cn。