Special Issues-04-03-2009

A fast enantiomeric separation of a chiral aromatic amine was achieved, using ultra high pressure liquid chromatography and highly sulfated β-cyclodextrin (S-β-CD) as a chiral additive in the mobile phase. The stationary phase consisted of a core shell support with a particle size of 2.7 µm. Under these conditions the baseline separation was obtained within 2.5 min. The influence of the concentration of the additive, along with the thermodynamics of the separation, were studied. Molecular mechanics calculations were consistent with the experimental data for the order of elution, providing further evidence of these interactions. The enantiomeric separation at high temperature (90 °C) using only water as mobile phase also was achieved for the first time.

Due to economic crisis all over the world it is a time of cost-friendly analyses. Superficially porous and monolithic columns are the tools to serve this purpose. These columns are new generation and can be used for ultrafast separations. This article describes the state-of-the-art for these stationary phases for high performance liquid chromatography (HPLC). The emphasis has been placed on their preparation, properties, applications, comparison, and future perspectives. It has been observed that superficially porous columns may be the choice of future for ultrafast separations.

The use and evolution of the two-dimensional liquid chromatography (LCxLC) technique is explored with respect to instrumentation and applications.

Special Issues

During the last four to five years, chromatographers have witnessed some significant advances in technology, from the instrument perspective, with systems operating up to 15,000 psi using new and significantly improved detectors, sometimes operating in multiple dimensions, and from the column perspective, with smaller particle sizes and new chemistries and configurations.

Over the past several years, charged aerosol detection (CAD) has become a widely used technology in the pharmaceutical laboratory. From formulation to stability and even quality control, many analysts are turning to this technology due to its advantages of sensitivity, ease of use, dynamic range, and applicability to a wide range of analyses in the drug development process. In this article, we will examine the operation and use of CAD in a regulated environment, briefly address method development and validation specifics, and highlight a few examples illustrating some of its advantages when used in the pharmaceutical laboratory.

The primary goal of early phase development is to gain a fundamental knowledge of the chemistry of drug substances and drug products to facilitate optimization of synthetic schemes and drug product formulations. At the same time, methods are required for release and stability studies to support clinical trials. Ultimately, the knowledge gained during early development translates into designing control methods for commercial supplies. Our approach to meeting this challenge is based upon the use of a primary method along with orthogonal methods. This paper will discuss the overall strategy, with an emphasis on the chromatographic conditions selected to provide systematic othogonality for a broad range of drugs. Case studies will be presented to demonstrate the utility of orthogonal methods to resolve issues that could not have been addressed using a single release and stability method.