Pharmaceutical impurity identification: A case study using a multidisciplinary approach

Isolation, identification and determination of the major degradation product in alprazolam tablets during their stability assay

“…The isolation methodology employed followed a similar scheme to that previously applied in our laboratory for a different analysis [6] and by others [7] and showed its usefulness as a general strategy.…”

Improved Protocol and Data Analysis for Accelerated Shelf-Life Estimation of Solid Dosage Forms

“…A calibration curve of DE* values versus the concentration of dehydroascorbic acid (Sigma-Aldrich) was used to quantify the amount of degradant in the ascorbic acid tablets. For the CP-456,773 tablets, analysis of the degradation was analogous to earlier reported methods (8). A dissolving solvent was prepared by combining 750 mL of 50 mM Na 2 HPO 4 with 250 mL of acetonitrile.…”

The design of a multi‐dimensional LC‐SPE‐NMR system (LC2‐SPE‐NMR) for complex mixture analysis

“…The traditional off-line approach to solving this problem has been the use of preparative, often multi-step, HPLC. 3 This approach is necessitated by the fact that despite advances in online NMR technology (including LC-NMR, 4 cryogenic probes, 5 and, lately, LC-SPE-NMR 6 ), the online system is still largely confined to the use of analytical scale chromatography and is, hence, unsuitable for effectively processing very low-level mixture components. 7 Recently, we demonstrated the use of semi-preparative chromatography coupled to NMR (through SPE) for lowlevel component analysis.…”