差示扫描量热法检测那格列奈多晶型

DETECTION OF CRYSTAL POLYMORPHS OF NATEGLINIDE BY DSC

目的 建立控制那格列奈B型晶体限度的DSC法。方法 测定一系列混合晶型浓度梯度组成的或某一确定组成的那格列奈对照品的ΔH值以及待测样品的ΔH值 ,以工作曲线法或比较法确定待测样品的B型组成。结果 在 0～ 15 %B晶组成时 ,重复性 0 61% ,回收率 86 3 %～ 12 7%。结论 此法可作为那格列奈混晶中B晶限度的检测方法。

AIM To establish the differential scanning calorimetric (DSC) methodology for controlling the crystal type B form of nateglinide. METHODS Accurately weighed pure dried (P 2O 5 as desiccant for 4 h at 80℃ in vacuum) fine powder of crystal type B and H of nateglinide were measured d Q /d T by DSC at heating rate of 10℃·min -1 and temperature between 100℃ and 200℃ to calculate the enthalpy Δ H B and Δ H H. Accurately weigh a series of uniform mixtures of crystal type B and H of dried fine powder of nateglinide in different proportions. The enthalpy of the mixtures is measured by DSC as above to calculate the enthalpy (ΣΔ H ). Using B% as X , ΣΔ H as Y , the regression equation was obtained. According to this equation, the unknown composition of mixed crystal was evaluated by the ΣΔ H values. The method was used to control the limitation of crystal type B of nateglinide by the ΣΔ H value of mixture of known composition as reference. RESULTS The results measured from different laboratories showed that the repeatability was 0 61% and the recoveries were 86 2%～127% when the amounts of crystal type B were between 0～15%.CONCLUSION This method can be used to evaluate the crystal type B composition of nateglinide.