Using Dachengqi Tang (DCQT) as a model, high performance liquid chromatography (HPLC) fingerprints were applied to optimize machine extracting process with the Box–Behnken experimental design. HPLC fingerprints were carried out to investigate the chemical ingredients of DCQT; synthetic weighing method based on analytic hierarchy process (AHP) and criteria importance through intercriteria correlation (CRITIC) was performed to calculate synthetic scores of fingerprints; using the mark ingredients contents and synthetic scores as indicators, the Box–Behnken design was carried out to optimize the process parameters of machine decocting process under high pressure for DCQT. Results of optimal process showed that the herb materials were soaked for 45 min and extracted with 9 folds volume of water in the decocting machine under the temperature of 140 1C till the pressure arrived at 0.25 MPa;then hot decoction was excreted to soak Dahuang and Mangxiao for 5 min. Finally, obtained solutions were mixed, filtrated and packed. It concluded that HPLC fingerprints combined with the Box–Behnken experimental design could be used to optimize extracting process of traditional Chinese medicine (TCM).

A rapid, simple and practical high-performance liquid chromatography method coupled with diode array detector (HPLC–DAD) was developed to evaluate the quality of Alisma orientale (Sam.) Juz. through a simultaneous determination of four major active triterpenes using a single standard to determine the multi-components (SSDMCs). Alisol B 23-acetate was selected as the reference compound for calculating the relative response factors. All calibration curves showed good linearity (R240.9998) within test ranges. RSDs for intra- and inter-day of four analytes were less than 3.6% and 2.3%; the overall recovery was 92.1–110.2%(SSDMC). The proposed method was successfully applied to quantify the four components in 20 samples from different localities in China. Moreover, significant variations were demonstrated in the content of these compounds. In addition, hierarchical clustering analysis (HCA) and principal components analysis (PCA) were performed to differentiate and classify the samples based on the contents of Alisol C 23-acetate, Alisol A, Alisol A 24-acetate and Alisol B 23-acetate. This simple, rapid, low-cost and reliable HPLC–DAD method using SSDMC is suitable for routine quantitative analysis and quality control of A. orientale (Sam.) Juz.

A specific, precise and stability indicating high-performance thin-layer chromatographic method for simultaneous estimation of pantoprazole sodium and itopride hydrochloride in pharmaceutical formulations was developed and validated. The method employed TLC aluminium plates precoated with silica gel 60F254 as the stationary phase. The solvent system consisted of methanol:water:ammonium acetate; 4.0:1.0:0.5 (v/v/v). This system was found to give compact and dense spots for both itopride hydrochloride (Rf value of 0.55±0.02) and pantoprazole sodium (Rf value of 0.85 ± 0.04). Densitometric analysis of both drugs was carried out in the reflectance-absorbance mode at 289 nm. The linear regression analysis data for the calibration plots showed a good linear relationship with R2=0.9988± 0.0012 in the concentration range of 100-400 ng for pantoprazole sodium. Also, the linear regression analysis data for the calibration plots showed a good linear relationship with R2=0.9990±0.0008 in the concentration range of 200-1200 ng for itopride hydrochloride. The method was validated for specificity, precision, robustness and recovery. Statistical analysis proves that the method is repeatable and selective for the estimation of both the said drugs. As the method could effectively separate the drug from its degradation products, it can be employed as a stability indicating method.

An electrochemical sensor incorporating a signal enhancement for the determination of lead (Ⅱ) ions (Pb2+) was designed on the basis of the thrombin-binding aptamer (TBA) as a molecular recognition element and ionic liquid supported cerium oxide (CeO2) nanoparticles-carbon nanotubes composite modification. The composite comprises nanoparticles CeO2, multi-wall carbon nanotubes (MWNTs)and hydrophobic room temperature ionic liquid (RTIL) l-ethyl-3-methylimidazolium tetrafluoroborate (EM1MBF4). The electrochemical sensors were fabricated by immersing the CeO2-MWNTs-EMIMBF4 modified glassy carbon electrode (GCE) into the solution of TBA probe. In the presence of Pb2+, the TBA probe could form stable G-quartet structure by the specific binding interactions between Pb2+ and TBA. The TBA-bound Pb2+ can be electrochemically reduced, which provides a readout signal for quantitative detection of Pb2+. The reduction peak current is linearly related to the concentration of Pb2+ from 1.0 × 10 8 M to 1.0 × 10-5 M with a detection limit of 5 × 109 M. This work demonstrates that the CeO2-MWNTs-EMIMBF4 nanocomposite modified GCE provides a promising platform for immobilizing the TBA probe and enhancing the sensitivity of the DNA-based sensors.

A sensitive electroanalytical method for quantification of pheniramine in pharmaceutical formulation has been investigated on the basis of the enhanced electrochemical response at glassy carbon electrode modified with multi-walled carbon nanotubes in the presence of sodium lauryl sulfate.The experimental results suggest that the phcniramine in anionic surfactant solution exhibits electrocatalytic effect resulting in a marked enhancement of the peak current response.Peak current response is linearly dependent on the concentration of pheniramine in the range 200-1500 μg/mL with correlation coefficient 0.9987.The limit of detection is 58.31 μg/m L.The modified electrode shows good sensitivity and repeatability.

An efficient method is provided to detect simultaneously some important veterinary drugs from different classes in highly complex animal tissue matrix.This method using matrix solid-phase dispersion (MSPD) and high performance liquid chromatography (HPLC) with diode array detection (DAD) is developed to effectively determine two fluoroquinolones (enoxacin and lomefloxacin),two sulfonamides (sulfanilamide and sulfamethoxazole) and one tetracycline (tetracycline) simultaneously in porcine tissues.In the process,MSPD methodology was used to treat samples,washed by n-hexane to remove lipid,eluted the analytes with acetonitrile-dichloromethane (1∶1,v/v).Solvent acetonitrile and solvent acetic acid (0.1％) were combined in a gradient.HPLC-DAD analysis of the tissue samples was performed within 15min at a flow rate of 1.0mL/min.The results showed that a recovery at 0.1,0.5 and 1.0 μg/g fortification levels ranged from 80.6％ to 99.2％ with satisfactory relative standard deviations (RSDs) (below 6.1％.n=3) and the limits of quantitation (LOQ) ranged from 7 μg/kg to 34 μg/kg in porcine tissues.Utilization of the method in successfully simultaneous analysis of porcine tissue incurred with veterinary drug multiresidues is described.

Although a number of methods are available for evaluating Linezolid and its possible impurities,a common method for separation if its potential impurities,degradants and enantiomer in a single method with good efficiency remain unavailable.With the objective of developing an advanced method with shorter runtimes,a simple,precise,accurate stability-indicating LC method was developed for the determination of purity of Linezolid drug substance and drug products in bulk samples and pharmaceutical dosage forms in the presence of its impurities and degradation products.This method is capable of separating all the related substances of Linezolid along with the chiral impurity.This method can also be used for the estimation of assay of Linezolid in drug substance as well as in drug product.The method was developed using Chiralpak IA (250 mm × 4.6 mm,5 μm) column.A mixture of acetonitrile,ethanol,n-butyl amine and trifluoro acetic acid in 96:4:0.10:0.16 (v/v/v/v) ratio was used as a mobile phase.The eluted compounds were monitored at 254 nm.Linezolid was subjected to the stress conditions of oxidative,acid,base,hydrolytic,thermal and photolytic degradation.The degradation products were well resolved from main peak and its impurities,proving the stability-indicating power of the method.The developed method was validated as per International Conference on Harmonization (ICH) guidelines with respect to specificity,limit of detection,limit of quantification,precision,linearity,accuracy,robustness and system suitability.

An approach was proposed to evaluate preparation technology by means of fingerprint-peak matching technology of high performance liquid chromatography with diode array detector (HPLC-DAD).Similarity and hierarchical clustering analysis (HCA) were applied to identify the 15 batches of Xiaochaihu granules from different manufacturers and our laboratory,and peak pattern matching between the composite formulae and Radix Bupleuri Chinensis,which was one of the main ingredients of Xiaochaihu granules,was utilized to evaluate the preparation technology of Xiaochaihu granules via the indexes of the relative deviation of retention time (RT) and UV spectrum feature similarity of their corresponding peaks.Eleven matching peaks were found between Xiaochalhu granules and Radix Bupleuri Chinensis.However,the saikosaponin A and saikosaponin D,which are the important active components in Radix Bupleuri Chinensis,were not found in Xiaochaihu granules from any manufacturers.The peak areas of 11 characteristic peaks of Xiaochaihu granules samples formed a matrix of 11 × 15.The result of HCA showed that Xiaochaihu granules samples were divided into four kinds of category.Xiaochaihu granules samples from the same manufacturer were basically clustered of the same category.The results suggested that the saikosaponin A and saikosaponin D are prone to structural transformation under the condition of decoction and in the presence of the organic acidic components.These active components,existing in raw herb,might transform to a series of non-active secondary saikosaponin due to unfavourable preparation technology.So the conventional decoction-based preparation technology of Xiaochaihu granules might greatly affect its quality and therapeutic effectiveness. This study demonstrates that fingerprint-peak matching technology can not only be used for quality control of this composite formulae,but also provide some guidance for preparation technology of Xiaochaihu granules.

A simple,precise,accurate,and stability-indicating method is developed and validated for analysis of tetrahydrozoline hydrochloride in eye drop formulations.Separation was achieved on a reversed-phase C8 column (125 mm × 4.6 mm i.d.,5 μm) using a mobile phase consisting of acetonitrile/phosphate buffer of pH 3.0 (20∶80,v/v) at a flow rate of 1.0 mL/min and UV detection at 240 nm.This method is validated according to United States Pharmacopeia requirements for new methods,which include accuracy,precision,selectivity,robustness,and linearity and range.This method shows enough selectivity,accuracy,precision,and linearity and range to satisfy Federal Drug Administration/International Conference on Harmonization regulatory requirements.The current method demonstrates good linearity over the range of 0.025-0.075 mg/mL of tetrahydrozoline with r2 0.999.The average recovery of the method is 100.8％ with a relative standard deviation of 0.47％.The degree of reproducibility of the results obtained as a result of small deliberate variations in the method parameters and by changing analytical operators has proven thai the method is robust and rugged.

CC chemokine receptor 4 (CCR4) is a kind of G-protein-coupled receptor, which plays a pivotal role in allergic inflammation. The interaction between 2-(2-(4-chloro-phenyl)-5-{[(naphthalen-1-ylmethyl)-carbamoyl]-methyl}-4-oxo-thiazolidin-3-yl)-N-(3-morpholin-4-yl-propyl)-acetamide (S009) and the N-terminal extracellular tail (ML40) of CCR4 has been validated to be high affinity by capillary zone electrophoresis (CZE). The S009 is a known CCR4 antagonist. Now, a series of new thiourea derivatives have been synthesized. Compared with positive control S009, they were screened using ML40 as target by CZE to find some new drugs for allergic inflammation diseases. The synthesized compounds XJH-5, XJH-4, XJH-17 and XJH-1 displayed the interaction with ML40, but XJH-9, XJH-10, XJH-11, XJH-12, XJH-13, XJH-14, XJH-3, XJH-8, XJH-6, XJH-7, XJH-15, XJH-16 and XJH-2 did not bind to ML40.Both qualification and quantification characterizations of the binding were determined. The affinity of the four compounds was valued by the binding constant, which was similar with the results of chemotactic experiments. The established CEZ method is capable of sensitive and fast screening for a series of lactam analogs in the drug discovery for allergic inflammation diseases.