Endocrine system on chip for a diabetes treatment model.

The endocrine system is a collection of glands producing hormones which, among others, regulates metabolism, growth and development. One important group of endocrine diseases is diabetes, which is caused by a deficiency or diminished effectiveness of endogenous insulin. By using a microfluidic perfused 3D cell-culture chip, we developed an 'endocrine system on chip' to potentially be able to screen drugs for the treatment of diabetes by measuring insulin release over time.

Pharmaceutical applications on columns packed with sub-2 microm particles.

During the last few years, there has been a great interest in the development of fast liquid chromatography. Among the reported approaches, the reduction of the particle size to attain sub-2microm diameter represents a good solution for achieving both increased separation power and faster analysis time. This paper demonstrates the chromatographic performance of such supports using plate-height curves and reveals the possibility for obtaining ultra-fast or highly efficient separations, according to the column geometry and system pressure limitations.

Validation of an ultra-fast UPLC-UV method for the separation of antituberculosis tablets.

A simple method using ultra performance LC (UPLC) coupled with UV detection was developed and validated for the determination of antituberculosis drugs in combined dosage form, i. e. isoniazid (ISN), pyrazinamide (PYR) and rifampicin (RIF).

High throughput liquid chromatography with sub-2 microm particles at high pressure and high temperature.

In this study, ultra performance liquid chromatography (UPLC) using pressures up to 1,000 bar and columns packed with sub-2 microm particles has been combined with high temperature mobile phase conditions (up to 90 degrees C). By using high temperature ultra performance liquid chromatography (HT-UPLC), it is possible to drastically decrease the analysis time without loss in efficiency. The stability and chromatographic behavior of sub-2 microm particles were evaluated at high temperature and high pressure.

Method transfer for fast liquid chromatography in pharmaceutical analysis: application to short columns packed with small particle. Part II: gradient experiments.

Liquid chromatography (LC) is currently considered as the gold standard in pharmaceutical analysis. Today, there is an increasing need for fast and ultra-fast methods with good efficiency and resolution for achieving separations in a few minutes or even seconds. A previous article (i.

Method transfer for fast liquid chromatography in pharmaceutical analysis: application to short columns packed with small particle. Part I: isocratic separation.

Liquid chromatography (LC) is considered to be the gold standard in pharmaceutical analysis. Today, there is a need for fast and ultra-fast methods with good efficiency and resolution for achieving separations in few minutes or even seconds. The present work describes a simple methodology for performing a successful method transfer from conventional LC to fast and ultra-fast LC.

Recent developments in liquid chromatography--impact on qualitative and quantitative performance.

In order to reduce the analysis time and maintain good efficiency in liquid chromatography (LC), several solutions are currently being investigated. The focus of this study was to compare, both qualitatively and quantitatively, the chromatographic performance of a conventional LC with selected approaches, namely monolithic supports, high temperature LC (up to 90 degrees C), and sub-2 microm particles combined with high pressure (up to 1000 bar). This comparison was achieved from a qualitative point of view with a special attention paid to the analysis of time reduction, efficiency improvement, and pressure constraint.

Fast analysis in liquid chromatography using small particle size and high pressure.

In order to enhance chromatographic performances in terms of efficiency and rapidity, LC has recently evolved in the development of short columns packed with small particles (sub-2 microm) working at high pressures (> 400 bar). This approach has been described 30 years ago according to the fundamental chromatographic equations. However, systems and columns compatible with such high pressures have been introduced in the market in 2004 only.

Chromatographic behaviour and comparison of column packed with sub-2 microm stationary phases in liquid chromatography.

In order to reduce the analysis time and maintain good efficiency in liquid chromatography, it is advisable to simultaneously decrease the column length and the particle size of the chromatographic support. Therefore, several manufacturers have developed and commercialized short columns filled with particles that have a diameter smaller than 2 microm. The focus of this work was to check the chromatographic performance of such columns and compare possibilities offered by sub-2 microm supports with conventional columns in terms of analysis time reduction and efficiency improvements.

Practical constraints in the kinetic plot representation of chromatographic performance data: theory and application to experimental data.

It is demonstrated that the kinetic plot representation of experimental plate height data can also account for practical constraints on the column length, the peak width, the viscous heating, and the mobile-phase velocity without needing any iterative solution routine. This implies that the best possible kinetic performance to be expected from a given tested support under any possible set of practical optimization constraints can always be found using a directly responding calculation spreadsheet template. To show how the resulting constrained kinetic plots can be used as a powerful design and selection tool, the method has been applied to a series of plate height measurements performed on a number of different commercial columns for the same component (butyl-parabene) and mobile-phase composition.