Fenghe Qiu

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Regulatory guidances for drug stability testing during early development stages lack specifics. Consequently, companies either conduct more stability studies than necessary just to avoid regulatory questions or perform insufficient stability work resulting in regulatory questions and delays in drug development. Hence, there exist a pressing need and a great(More)
In pursuit of continuous process improvement, the authors streamlined the drug substance (DS) stress and stability testing process from preclinical to the first clinical batch. High temperature/high humidity stress and ICH Q1B confirmatory photostability testing on an early DS batch provide stability data that help quickly assess the new DS stability(More)
Four unknown trace impurities (7-10) were observed in the capsule formulation of the HIV drug Tipranavir after prolonged storage at 30 degrees C/70% RH. Extensive NMR and LC/MS analyses revealed the compounds to be covalent adducts between TRIS, an excipient of the formulation, and diastereomeric Tipranavir alcohols formed via slow air oxidation of the drug(More)
During phase 1 and phase 2 drug development (early stage drug development), it is normal to continuously improve a manufacturing process, with changes made to the synthetic pathway, reagents, reaction conditions, crystallization parameters, drying conditions, or manufacturing equipment or scale or site. These manufacturing process changes (“process changes”(More)
The Boehringer-Ingelheim phosphinoimidazoline (BIPI) ligands were applied to the formation of chiral quaternary centers in the asymmetric Heck reaction. Several different substrates were examined in detail, using more than 70 members of this new ligand class. Hammett relationships were determined through systematic variation of the ligand electronics. All(More)
Tromethamine, a UV-transparent amine base excipient, was used in the liquid phase of a self-emulsifying drug delivery system-soft gelatin capsule (SEDDS-SGC) formulation as an emulsification agent and to improve solubilization of the active drug. The level of this excipient was found to be decreasing in aged and stressed drug product capsules. The decrease(More)
pH stress testing is an integral part of pharmaceutical stress testing and is a regulatory requirement for validating a stability indicating analytical method and elucidating degradation products and degradation pathways. This paper reports the results of an evaluation of iChemExplorer (ICE) for drug substance and drug product pH stress testing in(More)
Impurities in pharmaceutical products do not enhance the desired therapeutic effect and may, of course, have adverse effects. Impurities must therefore be limited or controlled for quality and safety considerations. Structural identification of an impurity is the first step in understanding the chemistry of its formation and subsequently controlling the(More)
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