帕拉米韦及其中间体酯化物结构的X射线衍射分析

目的 验证所合成的化合物为目标产物——帕拉米韦中间体酯化物及帕拉米韦成品,并通过X射线衍射技术探讨化合物晶型.方法 选择适宜的条件,培养出适合单晶X射线衍射分析的单晶体,对所得单晶数据进行结构解析,得到化合物的三维空间结构信息,与文献进行比对;同时通过单晶结构数据模拟获得化合物的粉末X射线衍射理论图谱,用于晶型研究.结果 单晶X射线衍射结构分析结果表明,帕拉米韦中间体酯化物及成品的化学结构、构型与文献报道完全一致:粉末X射线衍射理论图谱可作为晶型对照图谱使用,并进一步表明中间体存在多晶型现象.结论 单晶X射线衍射分析法可准确测定含多手性中心的帕拉米韦中间体酯化物及成品的空间结构,充分证实了该药物合成过程与结果的正确性;粉末X射线衍射理论图谱可为化合物晶型研究提供有力支持.     

托伐普坦的晶型研究

目的 研究低钠血症治疗药物托伐普坦的晶型特征。方法 采用蒸发结晶、溶析结晶、研磨转晶等方法对托伐普坦进行晶型制备筛选;采用粉末X射线衍射分析（PXRD）、差示扫描量热分析（DSC）、红外光谱分析（IR）、热重–差热分析（TG-DTA）以及单晶X射线衍射分析（SXRD）技术对制备得到的托伐普坦晶型样品进行表征;采用研磨、加热、加压和混悬方法对无水晶型进行转晶行为研究;此外,还对各种晶型进行了溶解性质研究。结果 通过上述制备方法获得了托伐普坦的4种晶型状态Ⅰ、Ⅱ、Ⅲ和Ⅳ型。其中Ⅰ型为无水晶型,Ⅱ型为溶剂化物,Ⅲ型为半水合物,Ⅳ型为无定型。Ⅰ、Ⅳ型在特定的条件下可以相互转化。结论 采用PXRD、DSC和TG-DTA技术可实现4种晶型的直观、快速、准确鉴别。Ⅰ～Ⅳ型托伐普坦的理化性质及稳定性存在明显差异,其中Ⅳ型为热力学不稳定晶型,溶解性最好,而Ⅰ型最稳定。     

托伐普坦片的制备及体外溶出评价

目的探讨流化床干燥法制备固体分散体,以改善托伐普坦的溶出度。方法以乳糖为底物,水溶性材料羟丙纤维素为载体,采用流化床干燥法制备托伐普坦固体分散体,利用粉末X射线衍射对固体分散体进行表征,并研究其体外溶出度。结果X射线衍射结果显示,托伐普坦在流化床干燥过程中转变成了无定形;体外溶出结果显示,固体分散体样品的溶出度优于物理混合物样品。结论采用流化床干燥法制成固体分散体,可显著提高托伐普坦的体外溶出度。     

托伐普坦固体分散体的制备及体外溶出特性考察

目的 采用固体分散技术提高难溶性药物托伐普坦的体外溶出度。方法 选用聚维酮K_29/32为载体材料,以溶剂蒸发法制备托伐普坦固体分散体。采用差示扫描量热法(DSC)、X-射线粉末衍射法(XRPD)对所得固体分散体进行鉴定, 并进行溶解度、体外溶出实验。结果 固体分散体的DSC 图谱及X-射线粉末衍射确定了托伐普坦以无定形态分散在载体中, 体外溶解实验表明其溶出较原料药、物理混合物均有明显提高。结论 将托伐普坦与PVP K_29/32制成固体分散体,其分散状态发生了改变,溶出性能明显提高。     

布南色林的单晶培养和结构确证

目的 培养布南色林的单晶,以验证所合成的化合物为布南色林.方法 通过温度、质量浓度、溶剂的考察,选择合适的条件,培养出大小适合X射线单晶衍射检测的布南色林单晶.结果 通过X射线单晶衍射测定,结果显示所得数据与文献报道一致,证明布南色林的化学结构正确.结论 采用本法可很好地获得大小适合X射线单晶衍射检测的布南色林单晶,并...     

那格列奈的新晶型

目的　确证降糖药那格列奈另一种新的晶型结构,称为S型。给出X射线衍射、红外图谱和相关数据。方法　用X射线粉末衍射、红外光谱、元素分析和差示扫描量热法作物相分析。结果　S型那格列奈有与文献报道的H型、B型完全不同的晶型。mp 172.04℃。结论　S型那格列奈是一种新的晶型     

复方新诺明有效成分的晶体结构及共晶研究

目的 研究复方新诺明中有效成分磺胺甲噁唑(SMZ)的单晶结构,研究其与甲氧苄啶(TMP)的共晶现象,为开发共晶新剂型提供实验支持.方法 采用加溶剂研磨法制备SMZ和TMP的共晶粉末,利用反射法测定红外光谱,采用差示扫描量热法(DSC)测定熔点,通过粉末X射线衍射(PXRD)研究晶型.通过溶剂挥发法得到SMZ的单晶,利用X射线单晶衍射仪测定其晶体结构.结果 SMZ的单晶属于单斜晶系,空间点群为C2/c,晶胞参数a=1.6209(10)nm,b=0.5527(3)nm,c=2.5955(16)nm,每个晶胞中有8个分子.共晶粉末的熔点为187.78℃,介于SMZ的熔点170.92℃和TMP的熔点201.96℃之间.与单独组分相比较,红外图谱的指纹区发生明显变化,PXRD产生新的X射线粉末衍射峰.结论 SMZ的单晶属于E型结构,SMZ和TMP通过研磨可以形成共晶,共晶现象引起红外、熔点和衍射峰的明显变化,研究结果为开发药物共晶新剂型提供实验基础.     

DL-乳酸伏硫西汀的单晶制备及其结构表征

目的培养DL-乳酸伏硫西汀的单晶,并对其进行结构表征。方法通过溶剂挥发法制备DL-乳酸伏硫西汀单晶,并采用热重分析仪(TGA)、差示扫描量热仪(DSC)、傅立叶变换红外光谱仪(IR)、粉末X射线衍射仪(PXRD)和单晶X射线衍射仪(SXRD)对其结晶形态进行表征。结果乙腈溶剂挥发法可以制备得到β晶型DL-乳酸伏硫西汀无色立方状单晶,其DSC和PXRD图谱与文献报道一致。单晶X射线衍射结果表明DL-乳酸伏硫西汀的化学计量式为C21H28N2O3S,相对分子质量为388.51,晶体密度为1.246 g/cm3,该晶胞属于单斜晶系,空间群为P21/c。结论采用X射线单晶衍射确证了DL-乳酸伏硫西汀单晶的结构,为DL-乳酸伏硫西汀的进一步开发提供了研究基础。     

阿普斯特的单晶制备及其表征

目的制备阿普斯特E晶型的单晶,并对其进行结构表征和稳定性研究。方法通过溶剂挥法制备出阿普斯特E晶型的单晶,采用差式扫描量热仪(DSC)、粉末X射线(PXRD)及单晶X射线仪(SXRD)对其进行表征,利用均浆实验对其晶型稳定性进行考察。结果乙腈溶剂挥发法可制备得到阿普斯特E晶型的单晶,其DSC和PXRD图谱与文献报道一致。SXRD结果表明阿普斯特E晶型的单位化学计量式为C_(22)H_(24)N_2O_7S,相对分子质量为460.49,晶体密度为1.262g/cm~3,该晶胞属于正方晶系,空间群为P4_12_12。均浆稳定性实验结果表明,不同极性溶剂中得到的晶体DSC图谱发生变化。结论实验确证了阿普斯特E晶型的立体构型,不同溶剂中晶型发生变化。     

甲磺酸多沙唑嗪多晶型表征研究

目的 研究甲磺酸多沙唑嗪晶型特征,为多晶型研究提供实验依据。方法 采用X射线粉末衍射法（XRPD）、差示扫描量热法（DSC）、热重法（TG）、红外光谱分析（IR）、拉曼光谱分析及溶解性试验对甲磺酸多沙唑嗪晶A型与晶H型进行多晶型研究。结果 获得甲磺酸多沙唑嗪晶A型与晶H型的表征图谱。结论 X射线粉末衍射法、差示扫描量热法与热重法可用于定性区分甲磺酸多沙唑嗪晶A型与晶H型,晶H型溶解度性质优于晶A型。     

泊沙康唑主环的单晶制备及其结构表征

目的制备泊沙康唑主环的单晶,并对其进行结构表征和稳定性研究。方法通过溶剂挥法及气相扩散法制备出泊沙康唑主环的单晶,采用差示扫描量热仪(DSC)、粉末X射线衍射仪(PXRD)和单晶X射线衍射仪(SXRD)对其结晶形态进行表征。结果上述方法均可制备泊沙康唑主环单晶,其DSC和PXRD图谱一致,即晶型一致。SXRD结果表明泊沙康唑主环不对称单位化学计量式为C_(21)H_(21)F_2N_3O_4S,相对分子质量为449.47,晶体密度为1.408 g/cm~3,该晶胞属于单斜晶系,空间群为P2_1。均浆稳定性实验结果表明,不同极性溶剂中得到的晶体PXRD图谱未发生变化。结论实验确证了泊沙康唑主环的立体构型,且稳定性良好。     

Enantiotropically-related polymorphs of {4-(4-chloro-3-fluorophenyl)-2-[4-(methyloxy)phenyl]-1,3-thiazol-5-yl} acetic acid: crystal structures and multinuclear solid-state NMR

Single crystal X-ray diffraction (SCXRD), powder X-ray diffraction (PXRD), and solid-state NMR (SSNMR) techniques are used to analyze the structures of two nonsolvated polymorphs of {4-(4-chloro-3-fluorophenyl)-2-[4-(methyloxy)phenyl]-1,3-thiazol-5-yl} acetic acid. These polymorphs are enantiotropically-related with a thermodynamic transition temperature of 35 +/- 3 degrees C. The crystal structure of Form 1, which is thermodynamically more stable at lower temperatures, was determined by SCXRD. The crystal structure of Form 2 was determined using PXRD structure solution methods that were assisted using two types of SSNMR experiments, dipolar connectivity experiments and chemical shift measurements. These experiments determined certain aspects of local conformation and intermolecular packing in Form 2 in comparison to Form 1, and provided qualitative knowledge that assisted in obtaining the best possible powder structure solution from the X-ray data. NMR chemical shifts for 1H, 13C, 15N, and 19F nuclei in Forms 1 and 2 are sensitive to hydrogen-bonding behavior, molecular conformation, and aromatic pi-stacking interactions. Density functional theory (DFT) geometry optimizations were used in tandem with Rietveld refinement and NMR chemical shielding calculations to improve and verify the Form 2 structure. The energy balance of the system and other properties relevant to drug development are predicted and discussed.     

(1R,2S)-2-(3,4-二氟苯基)环丙胺扁桃酸盐单晶的制备及结构解析

目的 制备(1R,2S)-2-(3,4-二氟苯基)环丙胺扁桃酸盐(TCGM3)单晶,并对其空间结构进行解析。方法 通过优化溶剂、温度等结晶工艺参数,制备TCGM3单晶,采用单晶X射线衍射技术对其进行空间结构解析。结果 外形完整的TCGM3单晶可通过甲醇体系室温蒸发4 d得到。单晶X射线衍射结果表明TCGM3该晶胞属于正交晶系,P212121空间群,结构偏离因子R=0.04,分子式为C17H17F2NO3,相对分子质量为321.32 g/mol,立体构型与预测构型一致。结论 通过单晶培养及对其进行单晶X射线衍射分析和结构解析,确证了TCGM3的空间结构。     

Characterization of physical mixtures and directly compressed tablets of sulfamerazine polymorphs: implications on in vitro release characteristics

The present study evaluates the effects of excipients, compression pressure, and relative humidity (RH) on the stability of sulfamerazine polymorphs (referred here as SMZ I and SMZ II) and their release from directly compressed tablets using differential scanning calorimetry (DSC), powder X-ray diffraction (PXRD), and dissolution analysis. SMZ I and SMZ II tablets were compressed with magnesium stearate (MGST), and microcrystalline cellulose (MCC) at 5000, 7500, and 10,000 lbs. pressures and stored at 40, 75, 95, and 100% RH conditions for 5 weeks. There were indications of possible drug-excipient interaction in the binary mixtures under different relative humidity conditions from the DSC data, but they could not be confirmed by PXRD because the crystal structures of the drug and excipients remained unaltered. The crystal structures of the polymorphs in the tablet also remained unaltered under the above conditions. There were, however, significant differences observed in the drug release properties of the two polymorphs. SMZ II was found in general to have a higher rate of drug release than SMZ I. Extensive gelation of MCC under higher moisture conditions, compression pressure during tableting, and inherent tabletability of the sulfamerazine crystals were factors that affected drug release. All these factors contributed towards prolonging the disintegration and deaggregation of the tablet particles and were therefore concluded to be the rate limiting steps for the dissolution process.     

Complementing high-throughput X-ray powder diffraction data with quantum-chemical calculations: Application to piroxicam form III

High-throughput crystallisation and characterisation platforms provide an efficient means to carry out solid-form screening during the pre-formulation phase. To determine the crystal structures of identified new solid phases, however, usually requires independent crystallisation trials to produce single crystals or bulk samples of sufficient quantity to carry out high-quality X-ray diffraction measurements. This process could be made more efficient by a robust procedure for crystal structure determination directly from high-throughput X-ray powder diffraction (XRPD) data. Quantum–chemical calculations based on dispersion-corrected density functional theory (DFT-D) have now become feasible for typical small organic molecules used as active pharmaceutical ingredients. We demonstrate how these calculations can be applied to complement high-throughput XRPD data by determining the crystal structure of piroxicam form III. These combined experimental/quantum–chemical methods can provide access to reliable structural information in the course of an intensive experimentally based solid-form screening activity or in other circumstances wherein single crystals might never be viable, for example, for polymorphs obtained only during high-energy processing such as spray drying or milling.     

A novel microsphere with a three-layer structure for duodenum-specific drug delivery

The ability to detect and quantify polymorphism of pharmaceuticals is critically important in ensuring that the formulated product delivers the desired therapeutic properties because different polymorphic forms of a drug exhibit different solubilities, stabilities and bioavailabilities. The purpose of this study is to develop an effective method for quantitative analysis of a small amount of one polymorph within a binary polymorphic mixture. Sulfamerazine (SMZ), an antibacterial drug, was chosen as the model compound. The effectiveness and accuracy of powder X-ray diffraction (PXRD), Raman microscopy and differential scanning calorimetry (DSC) for the quantification of SMZ polymorphs were studied and compared. Low heating rate in DSC allowed complete transformation from Form I to Form II to take place, resulting in a highly linear calibration curve. Our results showed that DSC and PXRD are capable in providing accurate measurement of polymorphic content in the SMZ binary mixtures while Raman is the least accurate technique for the system studied. DSC provides a rapid and accurate method for offline quantification of SMZ polymorphs, and PXRD provides a non-destructive, non-contact analysis.     

Polymorphism of a novel sodium ion channel blocker

2-[[4-(4-Fluorophenoxy)phenyl]-methylene]-hydrazinecarboxamide, a member of the semicarbazone family which has shown potential therapeutic use as anticonvulsants, has been found to exist in two polymorphic forms denoted A and B. In addition to reporting aspects of the physical characterization of both forms, the crystal structure of polymorph A has been determined directly from powder X-ray diffraction data using the Genetic Algorithm technique for structure solution, followed by Rietveld refinement. This structure is compared with that of polymorph B, which was determined previously from single crystal X-ray diffraction data. Knowledge of the crystal structures of the two polymorphs provides the opportunity for establishing structure-property relationships. This work further emphasizes the scope and utility of ab initio structure solution from powder X-ray diffraction data in the pharmaceuticals field.