Quantitative Detection for Polymorph of Levonorgestrel by Powder X-ray Diffraction / 医药导报

ABSTRACT

Objective According to the clinical medicinal crystal form———form γ of levonorgestrel, to establish the quantitative analysis method for levonorgestrel form γ by powder X-ray diffraction (PXRD) . Methods Firstly, single crystal X-ray diffractometry and powder X-ray diffractometry were used to confirm that the prepared levonorgestrel form γ was 100％ polymorphic purity, which provided a standard sample for quantitative analysis by single peak method; then, the standard samples of different quality levonorgestrel form γ for powder X-ray diffraction were weighed, the peak intensity values of characteristic diffraction peaks d = 6.4 , d = 6. 1  and d = 5. 6  of form γ as quantitative parameters selected, a linear relationship between the peak intensity value and the quality of form γ was established; finally, the content of levonorgestrel form γ was quantitatively analyzed. Results The peak intensity values of characteristic diffraction peaks d = 6.4 , d = 6.1  and d = 5.6  of levonorgestrel form γ and the quality showed a good linear relationship.In the range of form γ masses of 5 mg to 50 mg, the regression linear equations wereY = 459.59X+5 536.5, R2 = 0.993 0, Y = 430.03X+6 867.6, R2 = 0.990 5,Y = 615.95X+ 6 209.5, R2 = 0.990 8,respectively. Conclusion The method is simple, rapid, accurate and reliable, it can be used as quality control method for levonorgestrel polymorphs.