差示扫描量热法对尼群地平晶型的定量分析研究

Quantitative analysis of nitrendipine polymorph using differential scanning calorimetry

目的：针对尼群地平晶I型与晶IV型,建立其混晶原料药中晶型含量的定量分析方法。方法：采用差示扫描量热法,在分别考察晶I型、晶IV型样品质量与热量线性关系的基础上,通过配制尼群地平晶I型与晶IV型的不同含量混晶样品,建立其吸热峰热焓值与晶型含量间的线性关系,实现尼群地平混晶样品中晶型含量的定量分析。结果：尼群地平晶I型与晶IV型的吸热峰Peak值相差2℃,当混晶样品中晶I型含量小于10%或大于40%时,两种晶型的吸热峰无法区分,当混晶样品中晶I型含量在10%~40%范围内时,其含量与热焓具有良好的线性关系。结论：本方法具有试样微量化、操作简单、快速便捷、图谱易于分析等优势,可作为尼群地平晶型质量控制的限量方法使用。

Objective ：To establish a quantitative analysis method for the determination of contents of Form I and Form IV nitrendipine in the raw material. Methods：The linea relationship between the quality and heat of Form I and Form IV was investigated first. Mixed crystal samples of nitrendipine with different contents of Form I and Form IV were then prepared. Finally the linear relationship between the enthalpy and polymorphie content was established by differential scanning calorimetry（DSC）method for quantitative analysis of polymorphie content. Re- suits ：The temperature difference of endothermie peaks between Form I and Form IV was 2 ℃. When the content of Form I in the mixed crystal was lower than 10% or higher than 40% ,it was impossible to distinguish the two endo- thermic peaks. When the content of Form I in the mixed crystal was between 10% and 40% ,a good linear relation- ship was obtained between the enthalpy of endothermie peaks and crystal contents. Conclusion：The established method is simple,rapid,accurate and easy to analyze,it can be used as a limit control method for nitrendipine poly- morphs.