高效液相色谱法测定乳酸菌素制剂中乳酸对映体的含量与比例

HPLC determination of lactic acid enantiomeric content and ratio in lacidophilus preparation

目的:建立HPLC法对乳酸菌素制剂中L-乳酸和D-乳酸对映体进行拆分,并测定两者在乳酸菌素制剂中的含量与比例,运用L-乳酸和D-乳酸比值对搜集到的样本进行可能的工艺稳定性评价。方法:采用手性柱Chirex 3126(D青霉胺)-Phenomenex(250 mm×4.6 mm,5μm)色谱柱,以2 mmol·L^(-1)硫酸铜溶液-异丙醇(95∶5)为流动相,流速1.0 m L·min^(-1),紫外检测波长254 nm,柱温为30℃。结果:L-乳酸与D-乳酸质量浓度在0.10~1.04 mg·m L^(-1)范围内均呈良好线性(r=0.999 9);平均回收率(n=9)分别为97.5%和98.3%;检测限分别为0.094 4和0.124 6μg·m L^(-1);供试品溶液在48 h内稳定性良好;总体样本L-乳酸和D-乳酸比值在0.93~1.68之间。结论:该方法简单快捷,适合于乳酸菌素制剂中乳酸对映体的含量测定研究,用L-乳酸和D-乳酸比值经统计可以观察样本间离散程度,能反映出各厂间工艺稳定性水平。

Objective： To establish an HPLC method for enantiomer separation of L-lactic acid and D-lactic acid,assay the L-lactic acid and D-lactic acid isomer and their ratios in some lacidophilus preparations and use L-lactic acid and D-lactic acid ratio of the collected samples for possible evaluation of process stability. Methods： The separation was performed on a Chirex 3126（ D-penicillamine） chiral column（ 250 mm × 4. 6 mm,5 μm） and detected by ultraviolet detector（ UV）. The detection wavelength was set at 254 nm. The column temperature was set at 30 ℃.The mobile phase consisted of 2 mmol·L-1copper sulfate solution-isopropyl alcohol（ 95∶ 5） at a flow rate of 1. 0m L·min-1. Results： The calibration curve of L-lactic acid and D-lactic acid was linear in the range of 0. 10-（-1）. 04mg·m L-1（ r = 0. 999 9）; the average recoveries（ n = 9） of the method were 97. 5% and 98. 3%,respectively; the limits of detection were 0. 094 4 μg·m L-1and 0. 124 6 μg·m L-1,respectively; the sample solution was stable within 48 h. The ratio range of L-lactic acid to D-lactic acid in total samples was 0. 93-1. 68. Conclusion： The method is simple,accurate and sensitive,and suitable for the determination of L-lactic acid and D-lactic acid in lacidophilus preparation,and the L-lactic acid and D-lactic acid ratio of the statistical sample can be used to observe the degree of dispersion and reflect process stability level of each pharmaceutical factory.