A5101627490- Advanced NMR Techniques and Applications
- X-ray Diffraction in Crystallography
- Crystallization and Solubility Studies
- Solid-state spectroscopy and crystallography
- NMR spectroscopy and applications
- Crystallography and Radiation Phenomena
- Chemical Synthesis and Characterization
- Crystallography and molecular interactions
- Microencapsulation and Drying Processes
- Muon and positron interactions and applications
- Drug Solubulity and Delivery Systems
- Luminescence Properties of Advanced Materials
- Crystal Structures and Properties
- Atomic and Subatomic Physics Research
- Computational Drug Discovery Methods
- Advanced Drug Delivery Systems
- Polymer Synthesis and Characterization
- Food Quality and Safety Studies
- Peptidase Inhibition and Analysis
- Protein Degradation and Inhibitors
- Inorganic Fluorides and Related Compounds
- Multiple Myeloma Research and Treatments
- Boron and Carbon Nanomaterials Research
- Various Chemistry Research Topics
Boehringer Ingelheim (United States)
2021-2024
University of Windsor
2015-2023
Windsor Dermatology
2016-2022
Iowa State University
2019
Washington University in St. Louis
2011
In this work, we show how to obtain efficient dynamic nuclear polarization (DNP) enhanced 35Cl solid-state NMR (SSNMR) spectra at 9.4 T and demonstrate they can be used characterize the molecular-level structure of hydrochloride salts active pharmaceutical ingredients (APIs) in both bulk low wt% API dosage forms. SSNMR central-transition powder patterns chloride ions are typically tens hundreds kHz breadth, most cannot excited uniformly with high-power rectangular pulses or acquired under...
Herein, we demonstrate the use of 35Cl SSNMR for structural fingerprinting HCl salts pharmaceuticals in both bulk and dosage forms.
Producing amorphous solid dispersions (ASDs) by hot-melt extrusion (HME) is favorable from an economic and ecological perspective but also limited to thermostable active pharmaceutical ingredients (APIs). A potential technology shift spray-drying at later stages of drug product development a desirable goal, however bearing the risk insufficient comparability in vitro vivo performance final dosage form. Hot-melt was performed using API/polymer/surfactant mixtures with hydroxypropyl...
New mechanochemical preparations of three multicomponent crystals (MCCs) the form M Cl:urea· x H 2 O ( = Li, Na and Cs) are reported. Their structures were determined by an NMR crystallography approach, combining Rietveld refinement synchrotron powder X-ray diffraction data (PXRD), multinuclear 35 Cl, 7 23 133 solid-state (SSNMR) spectroscopy thermal analysis. The syntheses MCCs, two which novel, optimized for maximum yield efficiency. Cl SSNMR is well suited structural characterization...
Active pharmaceutical ingredients (APIs) can be prepared in many different solid forms and phases that affect their physicochemical properties suitability for oral dosage forms. The development commercialization of require analytical techniques determine quantify the API phase final drug product. 13C solid-state NMR (SSNMR) spectroscopy is widely employed to characterize pure formulated APIs; however, SSNMR experiments on with low loading are often challenging due sensitivity interference...
Crystallization is a widely used purification technique in the manufacture of active pharmaceutical ingredients (APIs) and precursor molecules. However, when impurities desired compounds have similar molecular structures, separation by crystallization may become challenging. In such cases, some form crystalline solid solutions with product during recrystallization. Understanding structure these recrystallized crucial to devise methods for effective purification. Unfortunately, there are...
Reliable methods for the characterization of drug substances are critical evaluating stability and bioavailability, especially in dosage formulations under varying storage conditions usage. Such must also give information on molecular identities structures any potential byproducts formulation process, as well providing a means quantifying relative amounts these substances. For example, active pharmaceutical ingredients (APIs) often formulated ionic salts to improve properties forms; however,...
A scalable synthesis of the SMARCA2 degrading PROTAC 1 was developed. The linker fragment derived from (S)-citronellol by oxidative cleavage and diastereoselective aryl Grignard addition to a N-tert-butanesulfinyl aldimine for generation chiral amine stereocenter one-pot borylation/Suzuki reaction biaryl formation. dipeptide prepared T3P-mediated coupling hydroxyproline benzyl ester N-Boc tert-leucine followed capping with 1-fluorocyclopropancarboxylic acid hydrolysis. Unification binding...
NaREF4 (rare-earth, RE = Y, Lu) nanocrystals (NCs) containing Ln3+-dopants are of great interest due to their unique ability downshift, downconvert, and upconvert light. While the luminescent properties microscale structures such NCs well understood, relatively little is known about molecular-level structures, nature NC cores shells, interactions stabilizing ligands at surface. To address these issues, we present a comprehensive characterization bulk β-NaYF4, one most commonly used hosts for...
Novel mechanochemical syntheses of cocrystals fluoxetine HCl are presented, along with characterization the molecular-level structures by<sup>35</sup>Cl solid-state NMR and DFT calculations.
Variable-hydrate active pharmaceutical ingredients (APIs) are known to form thermodynamically and kinetically stabilized solid phases over a continuous range of nonstoichiometric hydration levels. Some these forms can be problematic in the production dosage (e.g., tablets capsules), where manufacturing processes induce changes level API, resulting transformations undesirable that may affect product quality. In order improve development variable-hydrate APIs for commercial use, reliable...
Xylazine HCl (X) is a veterinary analgesic with many known solid forms, making it an ideal system for studying the noncovalent interactions, such as hydrogen bonding, that provide stability to polymorphs, solvates/hydrates, and cocrystal of pharmaceuticals. Herein, we report methods reliable preparation interconversion polymorphs X (including mechanochemical pathways), discovery novel polymorph, synthesis three cocrystals coformers containing amide carboxylic acid moieties. An understanding...
Multicomponent crystals of an artemisinin derivative and cinchona alkaloids were produced, combining two major types antimalaria drugs with unique hydrogen bond interactions. These salts demonstrate a new category antimalarial pharmaceuticals.
NMR crystallography is an emerging discipline that combines solid-state (SSNMR) spectroscopy, X-ray diffraction (XRD) methods, and computational approaches for the purposes of refining determining molecular-level structures in a wide array solids, including crystalline, semi-ordered, amorphous materials.[1-3]SSNMR can be utilized to provide information on interatomic distances, structural assignments, local atomic/molecular symmetries, and/or characterization disorder; these data, when used...