Objective In order to improve the diagnostic level of Crohn's disease( CD),the relevant literatures with CD in China were reviewed and the causes of misdiagnosis about CD were analyzed. Methods Papers on CD published in medical journals from 1989 to 2003 in CMCC and VIP are collected and reviewed one by one, and then the characteristics of the misdiagnosed and missed CD were recorded and the causes of these cases were analyzed. Results From 1989 to 2003, there are 428 papers about CD, of which 261 papers are about clinical studies(60.9%); In these papers, total of 3397 CD cases were reported. In these cases there are 2357 cases missed, clinical symptoms are various and complex including abdomen pain (62.5%),diarrhea(51.5%), abdomenal lumps(16.6%) and so on. The most commonly involved sites of CD are terminal ileum (62.5%), colon (26.9%) and ileum combining with colon (38.9%). Cranulomas were identified in 61.2% of operative specimens and in 27.6% of biopsy specimens. The most common missed diagnosed diseases are intestinal tuberculosis(32. 2% ), simplex intestinal block (23.2%) and intestinal block caused by tumor(6.4%) and acute appenditis(27. 9% ). There are 389 cases misdiagnosed as CD, the most common diseases are tuberculosis(53.5%), small intestinal lymphoma(14.4%) and colonal cancer (17.0%). Conclusion Papers on CD are increased gradually during the periods from 1989 to 2003 with rather high missed or misdiagnosis. As a result, it is necessary for us to improve the cognitzability on CD and to improve the accuracy of diagnosis.

Furbenicillin is a broad-spectrum semisynthetic penicillin with strong antibacterial activity against Gram-negative bacteria. Furbenicillin sodium is determined by volumetric method in current criteria. However, the criteria does not contain an assay of related substances of furbenicillin sodium. In this study, we established a method for detection and analysis of furbenicillin sodium and its related substances by HPLC. The analysis was performed with a C18 column under a gradient elution, the detection wavelength was 225 nm, and the column temperature was 35 degrees C. The reliability and accuracy of established method was validated in this study. Pure samples of furbenicillin sodium and its related substances were prepared. The structures, biological activities, and chromatographic retention behaviors of furbenicillin sodium and its related substances were identified using NMR, CLSI agar dilution method, and HPLC. All results in the current study provide ample evidence that this method is able to determine the reasonable limits in the quality-control protocol for furbenicillin sodium.
Anti-Bacterial Agents ; chemistry ; Chromatography, High Pressure Liquid ; Magnetic Resonance Spectroscopy ; Penicillins ; Quality Control ; Reproducibility of Results

Reference materials containing mixed degradation products of amoxicillin and ampicillin were developed after optimization of preparation processes. The target impurities were obtained by controlled stress testing, and each major component was identified with HPLC-MS and compared with single traceable reference standard each. The developed reference materials were applied to system suitability test for verifying HPLC system performed in accordance with set forth in China Pharmacopeia and identification of major impurities in samples based on retention and spectra information, which have advantages over the methods put forth in foreign pharmacopoeias. The development and application of the reference materials offer an effective way for rapid identification of impurities in chromatograms, and provide references for analyzing source of impurities and evaluation of drug quality.
Amoxicillin ; chemistry ; Ampicillin ; chemistry ; China ; Chromatography, High Pressure Liquid ; Drug Contamination ; Mass Spectrometry ; Reference Standards

Microbial control is one of the important parts of drug safety guarantee system. Chinese pharmacopoeia 2015 edition has constructed a complete system for pharmaceutical microbial control after continuous efforts since the 2005 edition. The new edition Chinese pharmacopoeia not only achieves the unity of three parts, but also makes harmonization between Chinese pharmacopoeia and ICH, thus is fully in line with international quality control system. In this paper, the revision progress of the last several editions of Chinese pharmacopoeia is reviewed. The main characteristics of pharmaceutical microbial control system in Chinese pharmacopoeia 2015 edition is clarified by revealing the formation process. The trend of this field in China is outlined by discussion on some hot issues.

The article introduces the main changes related to specifications of antibiotics in the Chinese Pharmacopoeia 2015, and discusses the trend of the quality control of antibiotics. The main strategy of antibiotic quality control in this edition of Chinese Pharmacopoeia has been changed to chemical analysis, with biological assay as auxiliary. The revision not only keeps in line with international standards, but also fully reflects the status of domestic antibiotic manufacturing and the quality control level. Solving the key points of specifications of antibiotics through development of new technologies and analysis methods is the trend in the field of antibiotic control in China.

AIMTo identify the components of acetylleucomycin and its hydrolytic products by LC-MS.

METHODSAcetylleucomycin was separated on a Diamonsil C18 column with 0.1 mol x L(-1) ammonium acetate-acetontrile (35 : 65) as mobile phase. The LC-MS was equipped with an electorspray ion source (ESI), which was set at the positive ion mode, and the mass spectra of each component in chromatogram were obtained with difference cone voltage.

RESULTSThe components of acetylleucomycin and its hydrolytic products can be separated by HPLC. The components were identified according to the molecular weight and its major mass fragment ions. The major components identified in domastic acetylleucomycin were acetylleucomycin A4, A5; acetylleucomycin A1, A3; acetylleucomycin A6, A7, and acetylleucomycin A13. The hydrolytic products of acetylleucomycin were not kitasamycin, but some non-complete hydrolytic product.

CONCLUSIONThe method is rapid, sensitive and specific. It' s suitable to application in the fields of multi-components antibiotics analysis.

Chromatography, Liquid ; methods ; Hydrolysis ; Josamycin ; analysis ; chemistry ; Kitasamycin ; analogs & derivatives ; analysis ; chemistry ; Leucomycins ; analysis ; chemistry ; Macrolides ; analysis ; chemistry ; Spectrometry, Mass, Electrospray Ionization ; methods

AIMTo identify the degradation compounds of cefathiamidine by a liquid chromatography-tandam mass spectrometry (LC-MS).

METHODSAccording to the accelerated storage condition, two main degradation compounds of cefathiamindine were its hydrolytic products. Cefathiamidine was separated on a C18 column, with 1% acetate solution-acetonitrile (85 : 15) as mobile phase. The mass spectra and MS/MS spectra were obtained with set at the positive ion mode. Combined the UV spectra and the chromatography behavior, the structures of two degradation compounds were identified.

RESULTSThe method can be used for the separation of the degradation compounds of cefathiamindine. The two major degradation compounds were desacetylcefathiamidine and cefathiamidine lactone.

CONCLUSIONThe method is rapid, sensitive and specific, and it is suitable for the identification of the degradation compounds of cephalosporin.

Anti-Bacterial Agents ; analysis ; metabolism ; Cephalosporins ; analysis ; metabolism ; Chromatography, High Pressure Liquid ; methods ; Reproducibility of Results ; Spectrophotometry, Ultraviolet ; methods ; Tandem Mass Spectrometry ; methods

The molecular descriptors of impurities with known structure in cefdinir were calculated, selected and associated with the chromatographic retention behavior to establish a model. This quantitative structure retention relationships (QSRR) model for the related substances of cefdinir was established under specific chromatographic condition and verified by other impurities. 12 molecular descriptors were used to establish the QSRR model, F_AFRBWF, Blbn_J, SsCH3, SssCH2, SsNH2, SssNH, SssS, SHdCH2, EEM_AFc, EEM_AFpl, EEM_XFpl and Pi_MaxQ. The relativity between true values and predictions in QSRR of cefdinir is R2 = 0.9836 (n = 18), ΔRRT is no more than 0.154, as 10.17% in RRT. The results indicate that the QSRR model for the related substances of cefdinir can be used to evaluate the analysis methods for related substances and predict the chromatographic behavior of new impurities, which will provide a new way for the evaluation of the effectiveness for drug quality control.
Cephalosporins ; chemistry ; standards ; Chromatography ; Models, Chemical ; Quality Control ; Structure-Activity Relationship

If the presence of residual solvents in pharmaceuticals exceeds tolerance limits as suggested by safety data, they may be harmful to the human body or the environment. It is because of this that the determination of residual solvents receives a great deal of attention. This paper reviews in detail the changes in the regulations on residual solvents in pharmaceuticals in leading pharmacopoeias, and the advances in the techniques involved, especially, the recent advances in the analytical techniques are summarized. At the end, the authors introduce the prospect of the expert system for determining residual solvents in pharmaceuticals based on the studies of their research group.
Capillary Electrochromatography ; Chromatography, Gas ; Drug Contamination ; prevention & control ; Drug and Narcotic Control ; Pharmaceutical Preparations ; chemistry ; Quality Control ; Solvents ; analysis

Re-evaluation of bioequivalence of generic drugs is one of the key research focus currently. As a means to ensure consistency of the therapeutic effectiveness of drug products, clinical bioequivalence has been widely accepted as a gold standard test. In vitro dissolution testing based on the theory of the BCS is the best alternative to in vivo bioequivalence study. In this article, the conventional dissolution method and flow-through cell method were used to investigate the dissolution profiles of domestic amoxicillin capsules in different dissolution media, and the absorption behavior of the drugs with different release rates (t85% = 15-180 min) in the gastrointestinal tract was predicted by Gastro Plus. The flow-through cell method was thought better to reflect the release characteristics in vivo, and amoxicillin capsules with regard to the release rates up to 45 min (t85% = 45 min) were having a satisfied bioequivalence with the oral solution according to the C(max) and AUC. Although two different dissolution profiles of domestic amoxicillin capsules were found by flow-through cell methods, prediction results revealed that domestic capsules were probably bioequivalent to each other.
Amoxicillin ; pharmacokinetics ; Capsules ; Computer Simulation ; Gastrointestinal Tract ; Humans ; Software ; Solubility ; Therapeutic Equivalency