Development of liquid chromatographic enantiomer separation methods and validation for the estimation of (R)-enantiomer in eslicarbazepine acetate.

Chiral separation method development was carried out for eslicarbazepine acetate and its (R)-enantiomer on diverse chiral stationary phases. Better chiral selectivity was observed on cellulose tris-(3,5-dichlorophenylcarbamate) immobilized column (Chiralpak IC-3). Under polar organic mode (POM), with 100% acetonitrile as mobile phase and 0.

Degradation studies of pentoxifylline: Isolation and characterization of a novel gem-dihydroperoxide derivative as major oxidative degradation product.

Pentoxifylline was subjected to various stress conditions and degradation profile was studied with conventional LCMS. Interestingly, under oxidative stress conditions the drug substance underwent distinct transformation to give rise to a single major degradation product. The structure of this product was elucidated using 1D, 2D NMR spectroscopy, high resolution mass spectrometry (Q-TOF LC/MS) and found to be a novel gem-dihydroperoxide, namely 1-(5,5-Bis-hydroperoxy-hexyl)-3,7-dimethyl-3,7-dihydro-purine-2,6-dione.