The quantitative monitoring of mechanochemical reaction between solid l-tartaric acid and sodium carbonate monohydrate by terahertz spectroscopy

Mechanistic and Kinetic Insight into Spontaneous Cocrystallization of Isoniazid and Benzoic Acid

“…The accelerating effect of a higher milling frequency on the reaction rate has been shown before 32 and is related to better mixing of the reactants and removal of the product from the reactant interface. Furthermore, milling with a higher frequency may introduce higher energy to the reaction system by creating crystal defects, strains and reducing the average particle size 28,29 . A higher density of defects in the crystallites would consequently lead 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 of the temperature during the reaction increases the vapour pressure of benzoic acid, which undergoes sublimation, therefore uniform experimental conditions are not maintained through the experiment.…”

“…The accelerating effect of milling is a result of reduced particle size, crystal defects, strains and mixing of the compounds. 28,29 The higher is the frequency of milling, the smaller particle size and larger surface area are achieved. The changes in particle size and morphology introduced by milling to isoniazid and benzoic acid crystallites were observed using scanning electron microscopy ( Figure 12).…”

Raman and terahertz spectroscopical investigation of cocrystal formation process of piracetam and 3-hydroxybenzoic acid

“…This result means that the cocrystals formed with different methods have the same molecular configuration which differs significantly from the crystal lattices of the single parent components. It is well-known that the cocrystallization occurs as the result of intermolecular hydrogen bonding, nonionic or other noncovalent interactions between two or more molecules of the different components [14][15][16]. So the experimental results indicate that the vibrational modes observed in these spectra are mostly intermolecular character resulting from intermolecular interactions such as hydrogen bonding effect between the parent 3-hBA and piracetam molecules during the cocrystal formation process.…”

“…Vibrational spectroscopy methods are wellbuilt tools for the characterization of pharmaceutical compounds. Focusing on the investigation of the fundamental vibrational modes, the methods contain traditional Fourier transformationinfrared (FT-IR) absorption [8][9][10], Raman scattering [11][12][13], and also terahertz (THz) spectroscopy [14][15][16][17][18]. During the last 20 years the use of Raman and THz spectroscopical techniques in the study of solid-state pharmaceutical compounds has been growing rapidity.…”

Kinetics of co-crystal formation with caffeine and citric acid via liquid-assisted grinding analyzed using the distinct element method

“…Fraction of co-crystal-2 [-] the reactant solids (Liu et al, 2011). Recrystallization of co-crystal-2 may also play a role in co-crystal formation in the present setting.…”