目的:研究盐酸乐卡地平Ⅰ、Ⅱ晶型及无定型对制剂制备的影响,为其制剂开发及一致性评价提供理论基础。方法:采用X-射线粉末衍射(XRD)、红外分光光度(IR)和差式扫描量热(DSC)法鉴定盐酸乐卡地平的3种晶型;采用XRD法比较粉粹、研磨、加压...目的:研究盐酸乐卡地平Ⅰ、Ⅱ晶型及无定型对制剂制备的影响,为其制剂开发及一致性评价提供理论基础。方法:采用X-射线粉末衍射(XRD)、红外分光光度(IR)和差式扫描量热(DSC)法鉴定盐酸乐卡地平的3种晶型;采用XRD法比较粉粹、研磨、加压工艺,湿法制粒中黏合剂溶剂(水、乙醇)和干燥温度(50、60、70℃)对盐酸乐卡地平3种晶型稳定性的影响;比较3种晶型盐酸乐卡地平片在水、盐酸、p H 4.5醋酸盐缓冲液、p H 6.8磷酸盐缓冲液4种介质中的体外溶出度。结果:XRD显示,Ⅰ、Ⅱ晶型均有特征衍射峰,且2θ值不一致,无定型无特征衍射峰;IR显示,3种晶型具有不同的吸收强度和吸收峰数目;DSC显示,Ⅰ、Ⅱ晶型分别在194.6、207.3℃有明显吸热峰,无定型在86.1℃有明显吸热峰、299.8℃有放热峰。粉粹、研磨、加压及干燥温度对3种晶型转变均无影响;湿法制粒时水对晶型转变无影响,乙醇会引起Ⅰ晶型的晶型转变。除在盐酸中Ⅰ晶型与Ⅱ晶型片比较f_2=68外,4种介质中3种晶型盐酸乐卡地平片溶出度两两比较的f_2均小于50。结论:XRD、IR、DSC法均能鉴定盐酸乐卡地平的3种晶型。用Ⅰ晶型制备盐酸乐卡地平片时,湿法制粒应避免使用乙醇作为黏合剂溶剂,建议使用水。不同晶型会影响所制盐酸乐卡地平片的体外溶出度。展开更多
A new kind of nano-crysta cellulose (NCC) prepared from natural cotton fiber has been obtained by the method ofacid hydrolysis. Compared to most other nanophase materials that derive from inorganic materials, our prod...A new kind of nano-crysta cellulose (NCC) prepared from natural cotton fiber has been obtained by the method ofacid hydrolysis. Compared to most other nanophase materials that derive from inorganic materials, our products are preparedfrom natural cotton fibers. The products are of spherical shape with mixed crystal forms of cellulose I and II. The preparationconditions determine the properties of the products. Prior treatment is a critical procedure. The properties of the products arealso strongly affected by such conditions as the kinds of acids used, the ratio of the acid mixture, the acid concentration, theultrasonic agitation time and hydrolysis temperature. The number average molecular weight of NCC is determined by gelpermeation chromatography (GPC). The particle size and shape were determined by transmission electron microscopy(TEM). X-ray diffraction was used to detect the crystallinity and average crystallite size of the panicle.展开更多
文摘目的:研究盐酸乐卡地平Ⅰ、Ⅱ晶型及无定型对制剂制备的影响,为其制剂开发及一致性评价提供理论基础。方法:采用X-射线粉末衍射(XRD)、红外分光光度(IR)和差式扫描量热(DSC)法鉴定盐酸乐卡地平的3种晶型;采用XRD法比较粉粹、研磨、加压工艺,湿法制粒中黏合剂溶剂(水、乙醇)和干燥温度(50、60、70℃)对盐酸乐卡地平3种晶型稳定性的影响;比较3种晶型盐酸乐卡地平片在水、盐酸、p H 4.5醋酸盐缓冲液、p H 6.8磷酸盐缓冲液4种介质中的体外溶出度。结果:XRD显示,Ⅰ、Ⅱ晶型均有特征衍射峰,且2θ值不一致,无定型无特征衍射峰;IR显示,3种晶型具有不同的吸收强度和吸收峰数目;DSC显示,Ⅰ、Ⅱ晶型分别在194.6、207.3℃有明显吸热峰,无定型在86.1℃有明显吸热峰、299.8℃有放热峰。粉粹、研磨、加压及干燥温度对3种晶型转变均无影响;湿法制粒时水对晶型转变无影响,乙醇会引起Ⅰ晶型的晶型转变。除在盐酸中Ⅰ晶型与Ⅱ晶型片比较f_2=68外,4种介质中3种晶型盐酸乐卡地平片溶出度两两比较的f_2均小于50。结论:XRD、IR、DSC法均能鉴定盐酸乐卡地平的3种晶型。用Ⅰ晶型制备盐酸乐卡地平片时,湿法制粒应避免使用乙醇作为黏合剂溶剂,建议使用水。不同晶型会影响所制盐酸乐卡地平片的体外溶出度。
基金This work was supported by the Special Funds for Major State Basic Research Projects (95-12 and G1999064800).
文摘A new kind of nano-crysta cellulose (NCC) prepared from natural cotton fiber has been obtained by the method ofacid hydrolysis. Compared to most other nanophase materials that derive from inorganic materials, our products are preparedfrom natural cotton fibers. The products are of spherical shape with mixed crystal forms of cellulose I and II. The preparationconditions determine the properties of the products. Prior treatment is a critical procedure. The properties of the products arealso strongly affected by such conditions as the kinds of acids used, the ratio of the acid mixture, the acid concentration, theultrasonic agitation time and hydrolysis temperature. The number average molecular weight of NCC is determined by gelpermeation chromatography (GPC). The particle size and shape were determined by transmission electron microscopy(TEM). X-ray diffraction was used to detect the crystallinity and average crystallite size of the panicle.
