HPLC测定(S)-4-苯基-2-噁唑烷酮的纯度

目的采用HPLC法测定(S)-4-苯基-2-噁唑烷酮(SPO)的纯度。方法采用Welchrom C18色谱柱,流动相为0.02 mol·L-1磷酸二氢钾(KOH调p H5)-乙腈(60∶40),检测波长210 nm,流速1.0 m L·min-1,柱温35℃。结果 SPO0.3036~6.072μg·m L-1与峰面积的线性关系良好(r=0.9999),检测限和定量限分别为0.9099、3.033 ng。结论所用方法准确、灵敏、快速,适用于检测SPO中的微量杂质。     

非水电位滴定法测定比沙可啶纯度及不确定度评定

目的:建立非水电位滴定法测定比沙可啶纯度的不确定度评定方法。方法:对采用非水电位滴定法测定比沙可啶纯度过程中引入的高氯酸滴定液浓度、方法重复性、仪器、比沙可啶摩尔质量、称量、滴定液消耗体积6个分量不确定度进行了系统分析。结果:置信概率为95%时,采用非水电位滴定法测定比沙可啶纯度结果的标准值及其不确定度为99.82%±0.53%。其中滴定液消耗体积、滴定液浓度和仪器不确定度3个分量对评定总不确定度贡献较大。结论:建立的非水电位滴定法不确定度评定结果可靠,其结果有利于提高比沙可啶的质量评价与控制水平,同时为比沙可啶纯度标准物质的研制提供了科学依据。     

红霉素溶析结晶过程中原溶剂对其晶习及纯度的影响研究

针对目前我国红霉素产品杂质含量高、外观较差等问题,研究了溶析结晶过程中异丙醇、正丙醇、丙酮、乙醇等原溶剂对红霉素结晶晶习及纯度的影响,实验结果发现丙酮和乙醇的混合溶剂（体积比３∶１）作为原溶剂可较好地改善红霉素晶习并提高其纯度。     

紫杉醇原料药纯度的HPLC测定

以五氟苯基填料色谱柱，经ＲＰ－ＨＰＬＣ测定紫杉醇原料药的纯度。与苯基色谱柱相比，能提高对紫杉醇与相关紫杉烷的选择性。     

中间体氨化物的纯度及其对氨氯吡咪原料药质量的影响

应用高效液相色谱考察了用于制备氨氯吡咪的中间体３，５－二氨基－６－氯－２－甲氧基－羰基吡嗪（氨化物）的纯度。色谱含量分析与熔点测定结果相互支持，氨化物含量高的粗品有高的熔点。用较高纯度的氨化物制备的氨氯吡咪的质量较高。     

Determination of the nateglinide polymorphic purity through DSC

It is well known that the control of the crystallization of drugs to ensure that only the approved and desired polymorph is present in the formulation is a crucial point of a preformulation study. In this regard, the aim of the present work is to devise a method for the quantification of the polymorphic purity of nateglinide in mixtures formed by polymorphs H and B. In order to achieve this goal, binary systems of known composition have been prepared and the melting peaks of both polymorphs have been recorded by differential scanning calorimetry. Experiments have determined that the method of preparation of the mixtures has to be carefully evaluated. Indeed it has been shown that grinding the samples induces transition from B to H form. Furthermore, it could be observed that the enrichment of the binary mixture with H form is caused by heating. Therefore, after having prepared the mixture without grinding stage, we propose a method to evaluate the content of H polymorph in mixture with the B one from the melting peak of B.     

Purity control of some Chinese crude herbal drugs marketed in Italy

The widespread use of herbal drugs, among which those coming from eastern Countries, has created a more compelling need for quality, a pre-requisite that can influence safety. In the present study, 10 Chinese crude herbal drugs marketed in Italy (Radix Ginseng, Radix Astragali, Rhizoma Coptidis, Rhizoma Atractylodis Macrocephalae, Radix Bupleuri, Radix Rehmanniae, Radix Paeoniae Alba, Pericarpium Citri Reticulatae, Radix Polygalae, Radix Salviae Miltiorrhizae) were analysed by the following purity assays: foreign matter, total ash, microbial and heavy metal contamination. Each herbal drug was purchased in Italy from three different sources: two Chinese firms and one Chinese herbal shop. Except for the heavy metal content, the tests were performed according to the European Pharmacopoeia. The presence of parasites was shown in two samples; moreover, level of ash (in three samples), lead content (in one sample) and total viable aerobic count (in one sample), were higher than the limits set by the European or Italian Pharmacopoeias. Our results, even if obtained from a small number of herbal drugs, show some purity issues and underline the importance of the quality control, particularly for this kind of products whose therapeutic value is not always demonstrated.     

Evaluation of an International Pharmacopoeia method for the analysis of ritonavir by liquid chromatography

A gradient LC method for the determination of related substances in ritonavir (RTV) has been recently published in the International Pharmacopoeia. The method uses a base-deactivated reversed-phase C18 column kept at a temperature of 35 degrees C. The mobile phases consist of acetonitrile, phosphate buffer pH 4.0 and water. UV detection is performed at 240 nm. A system suitability test (SST) is described to govern the quality of the separation. Since no brand names of columns are mentioned in pharmacopoeial texts, analysts often have problems to select a suitable stationary phase which is only described in general terms. So, the separation towards RTV components was investigated on 18 C18 columns and correlation was made with the column classification system developed in our laboratory. The method was further evaluated using a Hypersil BDS C18 column (25 cm x 4.6mm i.d.), 5 microm, which was also used for the development of the method. A central composite design was applied to examine the robustness of the method. The method shows good precision, linearity, sensitivity and robustness. Four commercial samples were examined using this method.     

An HPTLC method for the determination and the purity control of ciprofloxacin HCl in coated tablets

A high-performance thin-layer chromatographic method (HPTLC) has been developed for the determination and the purity control of a synthetic fluoroquinolone antibiotic ciprofloxacin hydrochloride in coated tablets when desfluoro compound, ethylene diamine compound, by-compound A and fluoroquinolonic acid are considered as impurities. Silica gel F₂₅₄ was used as a stationary phase and a mixture of acetonitrile, ammonia 25%, methanol and methylene chloride (1:2:4:4, v/v/v/v) as a mobile phase. The method was validated in terms of linearity (range), selectivity (placebo and related compounds), precision, accuracy (Recovery), system suitability (repeatability, peak symmetry, resolution) and impurities limit of detection (LOD). The analysis of variance (ANOVA) and t-test were applied to correlate the results of ciprofloxacin hydrochloride determination in coated tablets by means of the HPTLC method and the official British Pharmacopoeia (BP 1999) high-performance liquid chromatographic (HPLC) method.     

“He's a good-looking chap aint he?”: Narrative and visualisations of self in body dysmorphic disorder

Body Dysmorphic Disorder (BDD) is a condition marked by a distressing preoccupation with an imaginary or minor defect in a facial feature or a localised part of the body. However, the link between such excessive preoccupation and perceptions of self throughout the life course has rarely been examined. The aim of this study was to examine narrative accounts of the self across different life-time periods. Eleven participants diagnosed with BDD in England were recruited from the National Obsessive Compulsive Disorder (OCD) clinic and a BDD self-help group. In the context of a semi-structured interview participants presented photographs of themselves across a variety of time periods and drew a self-portrait to prompt memory and generate discussion. Transcribed interviews were analysed using Michele Crossley's (2000) narrative analytic approach. The findings suggest that the majority of participants perceived their past self as excessively attractive. Rather than believing that the alteration of their current appearance would rid them of BDD, participants indicated that a return to their former infantile and pure self that was devoid of blemish, defects and emotional responsibility would provide comfort. These findings indicate that the difficulties associated with appearance are less to do with beauty per se, but are more likely associated with narratives of loss, aging and decline and death.