Eva Furdyga

Direct determination of the racemate ratio of labetalol hydrochloride by HPLC

SummaryA direct, isocratic, reversed phase HPLC procedure is developed for the separation of the diastereomeric racemates of labetalol, a combined α- and β-adrenoreceptor antagonist. The aminoalcohol-type diastereomers were resolved on a C18 column using methanolwater-25% ammonia 27-75-2 mobile phase and detection at 220nm. The procedure is simple and convenient to carry out. The method may be of use in the determination of the individual diastereomeric racemates of labetalol in different forms such as bulk substance, pharmaceutical dosage preparations and biological fluids.

OPLC combined with NIR spectroscopy - A novel technique for pharmaceutical analysis

We report a new combination of overpressured-layer chromatography (OPLC) with near-infrared (NIR) spectroscopy for pharmaceutical analysis. Different pharmaceutical preparations containing caffeine, paracetamol, and acetylsalicylic acid as model compounds were separated by OPLC. The band density in the solid phase after OPLC was suitable for study of the separated components directly on the layer by NIR spectroscopy. We have demonstrated the applicability of rapid OPLC separation combined with UV densitometry and NIR spectroscopy for both qualitative and quantitative analysis. This OPLC—UV—NIR technique is thus suitable for rapid, nondestructive investigation of multicomponent pharmaceutical preparations and enables a different type of pharmaceutical analysis, e.g. starting-material tests, in-process control, end-product control, stability testing, etc. Another benefit of this newly developed combination of rapid off-line techniques is the possibility of simultaneous collection of qualitative and quantitative chromatographic and spectral information.