左炔诺孕酮微球有关物质测定方法研究

Determination of Related Substances in Levonorgestrel Microspheres

目的建立高效液相色谱(HPLC)测定左炔诺孕酮微球中的有关物质。方法采用Waters Symmetry Shield RP8(4.6 mm×250 mm,5μm)色谱柱;以甲醇-乙腈-水(体积比100∶266∶500)为流动相,等度洗脱,流速1.2 mL·min^(-1);柱温40℃;检测波长220 nm;进样量50μL。结果左炔诺孕酮峰与相邻杂质峰及各相邻杂质峰之间均能达到良好的分离,微球辅料对有关物质测定无影响;左炔诺孕酮的定量限为2.73 ng,检测限为1.4 ng;在0.07544~9.053μg·mL^(-1)范围内,相关系数为1.0000(n=8);重复性实验测定杂质总量的相对标准偏差(RSD)为7.5%(n=6)。结论本方法专属性强,灵敏度高,可用于左炔诺孕酮微球的质量控制。

OBJECTIVE To establish an isocratic elution method for determination of related substances of levonorgestrel microspheres.METHODS A C8 column(Waters Symmetry Shield RP84.6 mm×250 mm,5μm)was used.The mobile phase consisted of methanol-acetonitrile-water(100∶266∶500)and was eluted at the flow rate of 1.2 mL·min^(-1)and the column temperature was maintained at 40℃.The detection wavelength was set at 220 nm and the sample volume was 50μL.RESULTS Levonorgestrel,near peaks and other impurities were well separated from each other.All excipients of levonorgestrel microspheres did not influence the determination of related substance.The LOQ and LOD of levonorgestrel were 2.73 ng and 1.4 ng,respectively.The linearity of levonorgestrel ranged from 0.07544 to 9.053μg·mL^(-1)with a correlation coefficient of 1.0000(n=8).The repeatability RSD of total related substances(n=6)was 7.5%.CONCLUSION The proposed method shows high specify,accuracy and sensibility.It can be used for the quality control of levonorgestrel microspheres.