Thermally induced solid-state transformation of cimetidine. A multi-spectroscopic/chemometrics determination of the kinetics of the process and structural elucidation of one of the products as a stable N3-enamino tautomer

Exposure of cimetidine (CIM) to dry heat (160–180 °C) afforded, upon cooling, a glassy solid containing new and hitherto unknown products. The kinetics of this process was studied by a second order chemometrics-assisted multi-spectroscopic approach. Proton and carbon-13 nuclear magnetic resonance (NMR), as well as ultraviolet and infrared spectroscopic data were jointly used, whereas multivariate curve resolution with alternating least squares (MCR-ALS) was employed as the chemometrics method to extract process information. It was established that drug degradation follows a first order kinetics.     

The Influence of Silicon Dioxide on the Stability of the Phase Composition and Mechanical Properties of Alumina-Toughened Zirconia-Based Ceramics

Technical Physics - The influence of SiO2 impurity (with a concentration varying from 0 to 10 mol %) on the stability of tetragonal ZrO2 (t-ZrO2) and on a set of micro- and macromechanical...     

Vibration Properties of Thin Films of Transition 3d-Metals on the Cu (111) Surface

Russian Physics Journal - Using the potentials, generated by a tight binding approximation, the equilibrium atomic structure and the phonon spectra of Cr and Ni thin films (one monolayer) deposited...     

Gradient structure of polypropylene composites filled with carbon black

Russian Chemical Bulletin - Gradient polymer composites were prepared by melt-mixing of carbon black and polypropylene in a compounder and subsequent hot pressing of pellets. The thermally treated...     

Thermodynamic and structural characteristics of aqueous alkanolamine solutions

Journal of Structural Chemistry - Thermodynamic characteristics are calculated for aqueous alkanolamine solutions that are obtained by substituting alkyl radicals for the protons in the amino group...