World Congress on Biosensors 2014

World Congress on Biosensors 2014
Biosensors 2014

Thursday 6 June 2013

Just Published: Journal of Pharmaceutical and Biomedical Analysis

A new issue of this journal has just been published. To see abstracts of the papers it contains (with links through to the full papers) click here:
Journal of Pharmaceutical and Biomedical Analysis
http://rss.sciencedirect.com/publication/science/5266
Selected papers from the latest issue:

New protocol for αAstree electronic tongue enabling full performance qualification according to ICH Q2

06 June 2013, 09:19:54Go to full article
Publication date: September 2013
Source:Journal of Pharmaceutical and Biomedical Analysis, Volume 83
Author(s): Miriam Pein , Carolin Eckert , Maren Preis , Jörg Breitkreutz
Performance qualification (PQ) of taste sensing systems is mandatory for their use in pharmaceutical industry. According to ICH Q2 (R1) and a recent adaptation for taste sensing systems, non-specificity, log-linear relationships between the concentration of analytes and the sensor signal as well as a repeatability with relative standard deviation (RSD) values <4% were defined as basic requirements to pass a PQ. In the present work, the αAstree taste sensing system led to a successful PQ procedure by the use of recent sensor batches for pharmaceutical applications (sensor set #2) and a modified measurement protocol. Log-linear relationships between concentration and responses of each sensor were investigated for different bitter tasting active pharmaceutical ingredients (APIs). Using the new protocol, RSD values <2.1% were obtained in the repeatability study. Applying the visual evaluation approach, detection and quantitation limit could be determined for caffeine citrate with every sensor (LOD 0.05–0.5mM, LOQ: 0.1–0.5mM). In addition, the sensor set marketed for food applications (sensor set #5) was proven to show beneficial effects regarding the log-linear relationship between the concentration of quinine hydrochloride and the sensor signal. By the use of our proposed protocol, it is possible to implement the αAstree taste sensing system as a tool to assure quality control in the pharmaceutical industry.

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Comparative analysis of nucleosides and nucleobases from different sections of Elaphuri Davidiani Cornu and Cervi Cornu by UHPLC–MS/MS

06 June 2013, 09:19:54Go to full article
Publication date: September 2013
Source:Journal of Pharmaceutical and Biomedical Analysis, Volume 83
Author(s): Fengtao Li , Jin-ao Duan , Dawei Qian , Sheng Guo , Yuhua Ding , Xunhong Liu , Yefei Qian , Yunru Peng , Yijun Ren , Yu Chen
A rapid and sensitive hydrophilic interaction liquid chromatography method was developed for the identification and quantitative determination of 17 nucleosides and nucleobases by using ultra-high performance liquid chromatography separation system coupled to triple quadrupole mass spectrometer. Sufficient separation of the target compounds was achieved on an Acquity BEH Amide column (2.1mm×100mm, 1.7μm) in a single run of 9min. The LOD and LOQ were in the range of 0.017–50.00ngml−1 and 0.056–146.00ngml−1, respectively. Then, the method was applied for the analysis of nucleosides and nucleobases in Elaphuri Davidiani Cornu and Cervi Cornu. Multivariate statistical analysis was also used to investigate the differences in the nucleosides and nucleobases profiles among the samples. The present study also provided helpful information for quality control of Elaphuri Davidiani Cornu and Cervi Cornu.

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Stability of sample solution as a crucial point during HPLC determination of chemical purity of temozolomide drug substance

06 June 2013, 09:19:54Go to full article
Publication date: September 2013
Source:Journal of Pharmaceutical and Biomedical Analysis, Volume 83
Author(s): Łukasz Jedynak , Maria Puchalska , Marta Zezula , Marta Łaszcz , Wojciech Łuniewski , Joanna Zagrodzka
An HPLC method for determination of related substances in temozolomide drug substance was developed. Particular attention was paid to the stability studies due to the fact that temozolomide is unstable in a solution and quickly decomposes to its main degradation product 5-amino-4-imidazolecarboxamide (AIC). A mixture of diluted acetic acid and acetonitrile (4:1, v/v) as a diluent guaranteed lowering the decomposition of temozolomide in the solution. As it is not practically possible to fully eliminate the decomposition of temozolomide during an analysis, the mathematical correction of the results was proposed which allows to analyse almost five times more samples per week, comparing to the procedure without the application of the correction. The accuracy of the correction procedure was proved by investigating the recovery of AIC spiked to temozolomide solutions at different levels. Recoveries equalled 90–108% for AIC concentrations contained in the range of 0.30–1.80μgml−1. The developed method was validated according to the current guidelines, proving the suitability of the method for its intended purpose.

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Chemical differentiation of Da-Cheng-Qi-Tang, a Chinese medicine formula, prepared by traditional and modern decoction methods using UPLC/Q-TOFMS-based metabolomics approach

06 June 2013, 09:19:54Go to full article
Publication date: September 2013
Source:Journal of Pharmaceutical and Biomedical Analysis, Volume 83
Author(s): Jian-Bo Wan , Xu Bai , Xiu-Jiang Cai , Yi Rao , Yue-Sheng Wang , Yi-Tao Wang
In order to evaluate chemical consistency between traditional and modern decoctions of Da-Cheng-Qi-Tang (DCQT), a classical Chinese medicine formula commonly used in the treatment of digestive diseases, an ultra performance liquid chromatography-electrospray ionization-quadrupole time-of-flight mass spectrometry (UPLC-ESI-Q-TOFMS) combined with multivariate statistical analysis was established to globally characterize the chemical profile and discover differentiating chemical markers. Two kinds of decoctions, namely traditional decoction (multi-step decoction of constituent herbs), and modern decoction (one-step decoction of all herbs), were prepared and subjected to UPLC-MS analysis, the datasets of t R–m/z pairs, ion intensities and sample codes were processed with supervised orthogonal partial least squared discriminant analysis (OPLS-DA) to comprehensively compare the chemical difference between these two kinds of decoction samples. The global chemical difference was found between traditional and modern decoctions, and rhein, sennoside A/B, diosmetin, magnoloside B and naringin were the components contributing most to these differences. Based on the fact that traditional decoction of DCQT presents the higher concentration of rhein and sennoside A/B, mainly contributed to laxative activity of DCQT, the purgative effect of traditional decoction might be more potent, compared with modern decoction. However, the comparative study on purgative effect of traditional and modern DCQT remains to be further investigated using pharmacological approaches. Our findings also provide the early scientific evidence of traditional decoction method of DCQT.

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Real-time in vitro dissolution of 5-aminosalicylic acid from single ethyl cellulose coated extrudates studied by UV imaging

06 June 2013, 09:19:54Go to full article
Publication date: September 2013
Source:Journal of Pharmaceutical and Biomedical Analysis, Volume 83
Author(s): Mette Høg Gaunø , Thomas Vilhelmsen , Crilles Casper Larsen , Johan Peter Boetker , Jørgen Wittendorff , Jukka Rantanen , Jesper Østergaard
The purpose of this study was to investigate the in vitro release of 5-aminosalicylic acid from single extrudates by UV imaging and to explore the technique as a visualization tool for detecting film coating defects on extrudates coated with a thin ethyl cellulose layer. 5-Aminosalicylic acid extrudates were film coated with ethyl cellulose in a typical lab system coater equipped with one Wurster partition. Dissolution testing was performed first in a conventional paddle dissolution apparatus and second, in a flow through geometry equipped with a UV imaging system. Selected film coated extrudates from four different coating levels were placed in agarose gels and UV imaging was performed for a total of 240min. Absorbance maps were obtained thus visualizing the release of 5-aminosalicylic acid over time and it was possible to detect a decrease in release as a function of increased ethyl cellulose coating weight gain. Using a calibration curve the released amount was calculated and the individual release profiles for each coating weight gain in general resulted in comparable release profiles. Furthermore, the release profiles were consistent with the dissolution results obtained from the paddle dissolution testing. The release from defect extrudates was visualized by the absorbance maps and the release was highest from the compromised part of the extrudates. UV imaging has proven to be a useful technique to visualize the release of 5-aminosalicylic acid from single film coated extrudates and it has potential for detection of film coating defects.

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Development and validation of a fast chromatographic method for screening and quantification of legal and illegal skin whitening agents

06 June 2013, 09:19:54Go to full article
Publication date: September 2013
Source:Journal of Pharmaceutical and Biomedical Analysis, Volume 83
Author(s): B. Desmedt , V. Rogiers , P. Courselle , J.O. De Beer , K. De Paepe , E. Deconinck
During the last years, the EU market is flooded by illegal cosmetics via the Internet and a so-called “black market”. Among these, skin-bleaching products represent an important group. They contain, according to the current European cosmetic legislation (Directive 76/768/EEC), a number of illegal active substances including hydroquinone, tretinoin and corticosteroids. These may provoke as well local as systemic toxic effects, being the reason for their banning from the EU market. To control this market there is a need for a fast screening method capable of detecting illegal ingredients in the wide variety of existing bleaching cosmetic formulations. In this paper the development and validation of an ultra high pressure liquid chromatographic (UHPLC) method is described. The proposed method makes use of a Waters Acquity BEH shield RP18 column with a gradient using 25mM ammonium borate buffer (pH 10) and acetonitrile. This method is not only able to detect the major illegal (hydroquinone, tretinoin and six dermatologic active corticosteroids) and legal whitening agents, the latter having restrictions with respect to concentration and application (kojic acid, arbutin, nicotinamide and salicylic acid), but can also quantify these in a run time of 12min. The method was successfully validated using the “total error” approach in accordance with the validation requirements of ISO-17025. During the validation a variety of cosmetic matrices including creams, lotions and soaps were taken into consideration.

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