Authors:M. Szalka, J. Kostka, E. Rokaszewski, and K. Kaczmarski
The new analytical method of very high pressure liquid chromatography (VHPLC) has been designed for the estimation of related substances in bisoprolol fumarate. Several columns filled with sub-2-μm totally porous and shell adsorbent have been tested and compared during the method development. The columns' resolution was investigated. The shell adsorbent appears to have smaller resolution than the totally porous adsorbent. The tips and recommendations for the HPLC-VHPLC method transfer are presented. Significant reduction in analysis run time and solvent consumption has been obtained.
Resolution of racemic metoprolol, propranolol, carvedilol, bisoprolol, salbutamol, and labetalol, commonly used β-blockers, into their enantiomers has been achieved by TLC on silica gel plates impregnated with optically pure L
-Glu and L
-Asp. Acetonitrile-methanol-water-dichloromethane and acetonitrile-methanol-water-glacial acetic acid mobile phases in different proportions enabled successful separation. The spots were detected with iodine vapor. The detection limits were 0.23, 0.1, 0.27, 0.25, 0.2, and 0.2 μg for each enantiomer of metoprolol, propranolol, carvedilol, bisoprolol, salbutamol, and labetalol, respectively.
Authors:Ravi Bhushan, Jürgen Martens, Charu Agarwal, and Shuchi Dixit
Cu(II) complexes of L-threonine, L-serine, and L-tartaric acid were prepared and used as ligand exchange reagents for enantiomeric resolution of some of the β-blockers (bisoprolol, metoprolol, and propranolol) and a β2-agonist (salbutamol). Impregnated thin-layer plates were prepared by spreading slurry of silica gel prepared in the solutions of each of the three ligand exchange reagents. The spots were detected with iodine. Effect of temperature on enantioresolution was also studied. The detection limits were found in the range 0.19–0.26 μg for each enantiomer. L-Ser proved to be a good ligand using a common mobile phase in each case.
A chromatographic-densitometric method has been established for identification and quantitation of selected beta-adrenergic-blocking agents in pharmaceutical preparations. Retention factors,
, and characteristic absorption spectra of 11 drugs chromatographed on silica gel 60 F
HPTLC plates with six mobile phases were used for identification. Quantitation and validation of the method was performed for atenolol, acebutolol, propranolol, and bisoprolol using chloroform-methanol-ammonia, 15 + 7 + 0.2 (
), as mobile phase. UV densitometric measurements were performed at the wavelength of maximum absorption. Pharmaceutical preparations used in medicine and from a variety of manufacturers were analyzed and the method shown to be sufficiently sensitive for analysis of these samples. The limits of detection and determination ranged from 30 to 400 ng and recovery was from 97.14 to 102.18%. The precision of the method, described by the equation
, is good and the range of linearity is wide — from 0.020 to 0.250% for individual constituents.