Shenzhen Institute for Drug Control

Shenzhen, China

Shenzhen Institute for Drug Control

Shenzhen, China

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Han D.Q.,University of Macau | Han D.Q.,Shenzhen Institute for Drug Control | Zhao J.,University of Macau | Xu J.,University of Macau | And 3 more authors.
Journal of Pharmaceutical and Biomedical Analysis | Year: 2013

Polygonum multiflorum is one of the most commonly used Chinese medicines. In this study, an effective pressurized water extraction and HPLC method was developed for first simultaneous determination of 8 hydrophilic compounds, including gallic acid, Hypaphorine, Catechin, Proanthocyanidin B1, Epicatechin, Proanthocyanidin B2, Emodin-8-O-β-d-glucopyranoside, stilbene glycosides, in P. multiflorum. The analysis was performed on a Zorbax SB-AQ column with gradient elution of 0.05% phosphoric acid aqueous solution and acetonitrile in 45min. All calibration curves showed good linearity (R2>0.9994) within test ranges. The LOD and LOQ were lower than 0.2 and 1.0μg/mL on column, respectively. RSD for intra- and inter-day of 8 analytes were less than 4.1% and 4.0%, respectively, and the overall recovery was 96.0-100.7%. The validated method was successfully applied to quantification of 8 hydrophilic compounds in samples of P. multiflorum from different locations of China. Chemometrics such as principal component analysis (PCA) and hierarchical clustering analysis (HCA) were used to evaluate homogeneity of P. multiflorum in China, which suggested that their quality homogeneity was good. © 2012 Elsevier B.V.

Yu H.,Shenzhen Polytechnic | Xu L.,Shenzhen Institute for Drug Control | Chen S.,Shenzhen University
Ultrasonics Sonochemistry | Year: 2014

Ultrasound is a very promising technology to mediated drug/gene transferring into cells. However the relations between cell experimental conditions and results have been still unknown. It seriously impeded the development of the technology. In the article, a transfer efficiency model for ultrasound mediated drug/gene transferring into cells in stable cavitation was constructed. To testify the model, the numerical results were compared with the cell experimental data from six literatures in the entirely different experimental conditions. The numerical results fit the cell experimental data well. Despite simplifications and limitations, the model for the first time established the relationship between the cell experimental results about transfer efficiency and the conditions including ultrasound, microbubble and cells in stable cavitation. © 2013 Elsevier B.V. All rights reserved.

Yu H.,Shenzhen Polytechnic | Lin Z.,Shenzhen Institute for Drug Control | Xu L.,Shenzhen Institute for Drug Control | Liu D.,University of Minnesota | Shen Y.,Shenzhen University
Ultrasonics | Year: 2015

Abstract Sonoporation is a promising technology for promoting the transfer of drug or gene into cells using ultrasound-mediated microbubbles that transiently break up the cell membrane. In this article, a model is established to analyze the dynamics of ultrasound-mediated microbubble near the cell membrane, which may be especially useful for understanding the mechanisms of sonoporation. In the model, the velocity potential of fluid on the microbubble surface and on the cell membrane is obtained by the unsteady Bernoulli equations, and it is solved by using the boundary integral equations. By numerically analyzing the model, the typical microbubble dynamics near the cell membrane are enumerated, which may be mainly governed by mechanical index. The model also established the connections among the parameters of ultrasound exposure, microbubble characteristics, and cell membrane properties in sonoporation. © 2015 Elsevier B.V.

Zhao J.,Southern Medical University | Su C.,Shenzhen Institute for Drug Control | Yang C.,Sun Yat Sen University | Liu M.,Sun Yat Sen University | And 3 more authors.
Journal of Pharmaceutical and Biomedical Analysis | Year: 2012

A sensitive rapid resolution liquid chromatography-tandem mass spectrometry method was developed to determine the pharmacokinetics of ginsenoside Rb 1, Rb 2, and Rb 3 in rats, after oral administration (50mg/kg) and intravenous administration (10mg/kg) of Rb 1, Rb 2, and Rb 3, respectively. The plasma samples were extracted by saturated N-butanol with Rg 2 as internal standard. Chromatographic separation was performed on a Zorbax SB-C18 column (50mm×4.6mm, 1.8μm) with a mobile phase consisting of methanol and 1mM ammonium formate (74:26, v/v). Multiple reaction monitoring mode was performed using the fragmentation transitions of m/z 1107.7→m/z 178.9, m/z 1077.7→m/z 148.6, and m/z 1077.7→m/z 783.4 for Rb 1, Rb 2, and Rb 3, respectively. Calibration curves were recovered over a concentration range of 20-1000ng/ml for Rb 1 and Rb 2, and 50-2500ng/ml for Rb 3. The limits of detection were 3.0ng/ml, 4.0ng/ml, and 6.5ng/ml. Both intra-day and inter-day variances were less than 15% and the accuracy was within 86-114% for the three ginsenosides. All three ginsenosides had poor oral bioavailability (0.78%, 0.08%, and 0.52% for Rb 1, Rb 2, and Rb 3, respectively). The value of Rb 1 is higher than that of Rb 2 or Rb 3, indicating that ginsenosides with hexose and hydroxyl groups (Rb 1) could present better pharmacokinetic behaviors than those with pentose groups in the same glycosylation site by oral administration. © 2012 Elsevier B.V.

Li S.,Hong Kong Baptist University | Jin Y.,Shenzhen Institute for Drug Control | Tang Z.,Hong Kong Baptist University | Lin S.,Hong Kong Baptist University | And 3 more authors.
Analytica chimica acta | Year: 2015

Ribonucleosides are the end products of RNA metabolism. These metabolites, especially the modified ribonucleosides, have been extensively evaluated as cancer-related biomarkers. However, the determination of urinary ribonucleosides is still a challenge due to their low abundance, high polarity and serious matrix interferences in urine samples. In this study, a derivatization method based on a chemical reaction between ribonucleosides and acetone to form acetonides was developed for the determination of urinary ribonucleosides. The derivative products, acetonides, were detected by using liquid chromatography-tandem mass spectrometry (LC-MS/MS). The methodological evaluation was performed by quantifying four nucleosides for linear range, average recovery, precision, accuracy and stability. The validated procedures were applied to screen modified ribonucleosides in urine samples. Improvement of separation and enhancement of sensitivity were obtained in the analysis. To identify ribonucleosides, inexpensive isotope labeling acetone (acetone-d6) and label-free acetone were applied to form ordinary and deuterated acetonides, respectively. The two groups of samples were separated with orthogonal partial least squares (OPLS). The ordinary and deuterated pairs of acetonides were symmetrically distributed in the S-plot for easy and visual signal identification. After structural confirmation, a total of 56 ribonucleosides were detected, 52 of which were modified ribonucleosides. The application of derivatization, deuterium-labeling and multivariate statistical analysis offers a new option for selective detection of ribonucleosides in biological samples. Copyright © 2015 Elsevier B.V. All rights reserved.

Zhu K.Y.,Chinese University of Hong Kong | Leung K.W.,Chinese University of Hong Kong | Ting A.K.L.,Chinese University of Hong Kong | Wong Z.C.F.,Chinese University of Hong Kong | And 7 more authors.
Analytical and Bioanalytical Chemistry | Year: 2012

A microfluidic chip based nano-HPLC coupled to tandem mass spectrometry (nano-HPLC-Chip-MS/MS) has been developed for simultaneous measurement of abused drugs and metabolites: cocaine, benzoylecgonine, cocaethylene, norcocaine, morphine, codeine, 6-acetylmorphine, phencyclidine, amphetamine, methamphetamine, MDMA, MDA, MDEA, and methadone in the hair of drug abusers. The microfluidic chip was fabricated by laminating polyimide films and it integrated an enrichment column, an analytical column and a nanospray tip. Drugs were extracted from hairs by sonication, and the chromatographic separation was achieved in 15 min. The drug identification and quantification criteria were fulfilled by the triple quardropule tandem mass spectrometry. The linear regression analysis was calibrated by deuterated internal standards with all of the R 2 at least over 0.993. The limit of detection (LOD) and the limit of quantification (LOQ) were from 0.1 to 0.75 and 0.2 to 1.25 pg/mg, respectively. The validation parameters including selectivity, accuracy, precision, stability, and matrix effect were also evaluated here. In conclusion, the developed sample preparation method coupled with the nano-HPLC-Chip-MS/MS method was able to reveal the presence of drugs in hairs from the drug abusers, with the enhanced sensitivity, compared with the conventional HPLC-MS/MS. © 2012 Springer-Verlag.

Yu H.,Zhejiang University | Chen S.,Shenzhen University | Cao P.,Shenzhen Institute for Drug Control
Ultrasonics Sonochemistry | Year: 2012

Low intensity ultrasonic therapy is always an important research area of ultrasonic medicine. This review concentrates on low intensity ultrasound enhancing bactericidal action of antibiotics against bacteria in vitro and in vivo, including planktonic bacteria, bacterial biofilms, Chlamydia, and bacteria in implants. These literatures show that low intensity ultrasound alone is not effective in killing bacteria, while the combination of low intensity ultrasound and antibiotics is promising. Low intensity ultrasound facilitating antibiotic treatment is still in its infancy, and still requires a great deal of research in order to develop the technology on medical treatment scale. © 2011 Elsevier B.V. All rights reserved.

Jin Y.,Shenzhen Institute for Drug Control
Chinese Journal of New Drugs | Year: 2014

Toxicologic pathology report is an indispensable content in drug safety evaluation of new drug research and application. The value of pathological diagnosis is limited because of problems in dyeing methods, equipments and other experimental conditions, and the diagnosis is affected by pathologist's personnel knowledge and experience that unavoidably possess subjectivity. Therefore, peer review based on unified, standardized and scientific terminology is an essential element. Due to the toxicologic pathology in China is still in the developing stage, diagnostic terms among pathologists are quite different, so that sometimes the same pathological change might be given many similar terms but have completely different pathogenesis. In this article, the definition, pathogenesis, light microscopic observation and confirming methods of hepatocellular vacuolation and necrosis were discussed mainly combined with current situation of the diagnose based on hematoxylin-eosin stained sections, and unifying the nomenclature for rat and mouse hepatocellular vacuolation and necrosis was suggested. ©, 2014, Chinese Journal of New Drugs Co. Ltd. All right reserved.

Jin Y.,Shenzhen Institute for Drug Control
Chinese Journal of New Drugs | Year: 2016

In 2013, China Food and Drug Administration (CFDA) released “technical guidelines for chemical substances irritation, sensitization and hemolytic study (2005)” for public consideration. Nine of the suggestions were put forward by Prof. Yuan Bo-jun and me, according to the author's papers of irritation test standardization published in “Chinese Journal of New Drugs” and other journals. In 2014, CFDA released a new version of “technical guidelines of drug irritation, sensitization and hemolytic study”. Interpretation and suggestions on the new guidelines were given after nearly 1-year practice. © 2016, Chinese Journal of New Drugs Co. Ltd. All right reserved.

Zhang G.,Shenzhen Institute for Drug Control | Yu Y.,Shenzhen Institute for Drug Control | Wu X.,Shenzhen Institute for Drug Control | Li J.,Shenzhen Institute for Drug Control
Journal of Pharmaceutical and Biomedical Analysis | Year: 2014

A new tadalafil analogue was detected and isolated from a dietary supplement, the structure was elucidated by means of nuclear magnetic resonance (NMR) and mass spectroscopy. The compound was determined to be diethylaminopretadalafil, which might be derived from a precursor in the synthesis of tadalafil. © 2014 Elsevier B.V.

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