No abstract

A capillary electrophoresis (CE) method was developed for the stereoselective determination of the non-steroidal anti-inflammatory drug (NSAID), S-naproxen, in tablets. Several i-cyclodextrin derivatives (CDs) were tested as chiral selectors, including sulfobutyl-i-CD (SBCD), carboxymethyl-i-CD (CMCD), dimethyl-i-CD (DMCD) and trimethyl-i-CD (TMCD), in a phosphoric acid/triethanolamine pH 3 buffer. Under these conditions, the analyte was mainly present in an uncharged form and therefore, the use a neutral CD (DMCD or TMCD) alone could not lead to enantiomeric separation. On the contrary, by addition of a charged CD (SBCD or CMCD) to the running buffer, giving the analyte enantiomers an adequate mobility, chiral resolution could be achieved, although the resolution values obtained in this case were not quite satisfactory (RsB 1.5). Dual systems, based on the use of mixtures of charged and neutral CDs, were then investigated. The SBCD/TMCD system was found to be particularly well suited to the enantioseparation of naproxen and after optimisation of the concentrations of both CDs, a resolution value of 5.4 could be obtained. The method was validated for the determination of R-naproxen (enantiomeric impurity) in the 0.1-2% range, using the racemic mixture of the analyte. A second validation was performed in the 50 -150% range for the quantitation of S-naproxen. In both cases, good results with respect to linearity, precision and accuracy were obtained.

New energy-density functionals (EDFs) inspired by effective-field theories have been recently proposed. The present work focuses on three such functionals, which were developed to produce satisfactory equations of state for nuclear matter. We aim to extend these functionals to treat finite systems including a spin-orbit contribution and pairing correlations. We illustrate here a first step towards this direction, namely a generalization of such functionals tailored to perform applications to neutron gases confined in harmonic traps. Sets of available ab initio results are used as benchmark pseudo-data for adjusting the additional parameters (with respect to the nuclear matter case) that have to be introduced for finite-size systems. Several quantities are predicted and compared to ab initio and other EDF results such as total energies, potentials, and density profiles. The associated effective masses are also analyzed. Two of these functionals globally provide predictions that are close to one another as well as to ab initio values when available. It is shown that, in general, this is not the case for several currently used Skyrme functionals. Directions for improving the third functional are discussed. * bonnard@ipno.in2p3.fr †