Effects of solvent composition and temperature on polymorphism and crystallization behavior of thiazole-derivative

Kitamura, Mitsutaka; Nakamura, Kazuhiko

doi:10.1016/s0022-0248(02)00828-x

Cited by 26 publications

(45 citation statements)

References 14 publications

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“…A similar transformation from BH to D was also observed at 323 K at V MeOH 0.8. This may indicate that the transformation between hydrated crystals, BH, and solvated D crystals is very easy because of the similar configurations of the carboxylic acid group, which were observed with Fourier transform infrared (FTIR) [12]. At 303 K, both A and BH crystals transformed into D crystals at V MeOH 0.7 (Fig.…”

Section: Effects Of Temperature On Solubility and Transformation Of Pmentioning

confidence: 63%

“…BPT has three polymorphs (A, B, C) and two solvated crystals-hydrated crystal, BH (BPTؒH 2 O) and methanolated crystal, D (BPTؒMeOH) [12]. In atmosphere, the BH crystal loses very slowly the solvated water molecules and becomes an anhydrous crystal (B).…”

Section: Methodsmentioning

confidence: 99%

“…The suspension was filtrated, and the solution's change of concentration over time was measured by a UV spectroscopic method, using adsorption at 317 nm. The filtrated crystals were dried in atmosphere, and the transformation behavior was examined by analyzing the polymorphous composition of the crystals by X-ray diffraction (XRD), using the characteristic peak [12]. Solubility measurements were carried out in a temperature range between 303 and 323 K.…”

Section: Methodsmentioning

confidence: 99%

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Thermodynamic stability and transformation of pharmaceutical polymorphs

Kitamura

2005

Pure and Applied Chemistry

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Abstract:The thermodynamic stability and transformation of pharmaceutical polymorphs was investigated, especially those of the thiazole derivative pharmaceutical, 2-(3-cyano-4-isobutyloxyphenyl)-4-methyl-5-thiazolecarboxylic acid (BPT). The influence of methanol compositions in solvents and temperature on the solubility and the transformation behavior of BPT was clarified. The transformation behavior was explained by the chemical potential difference between the stable and metastable forms. It was shown that a specific solute-solvent interaction contributes to the preferential nucleation and growth of the stable or metastable forms and influences the transformation behaviors. The solubility of BPT of the solvated crystals is much more influenced by the solvent compositions than the true polymorphs. The solubility ratio of the solvated crystals depends on the solvent composition, whereas the solubility ratio of the true polymorphs is considered to be independent of the solvents. The crystallization behavior was also investigated. The transformation rate after crystallization appeared to depend on the initial concentration of BPT and the addition rate of the antisolvent. The cause of this phenomenon was presumed to be a slight inclusion of the stable form in the metastable form.

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Section: Effects Of Temperature On Solubility and Transformation Of Pmentioning

confidence: 63%

Section: Methodsmentioning

confidence: 99%

Section: Methodsmentioning

confidence: 99%

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Thermodynamic stability and transformation of pharmaceutical polymorphs

Kitamura

2005

Pure and Applied Chemistry

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“…Several parameters affect the formation of a polymorph such as solvent, certain impurities or additives, concentration, temperature, the geometry of covalent bonds, and the stirring conditions [17][18][19]. It is noteworthy that with 2:1 M ratio of [20][21][22][23][24][25].…”

Section: Spectroscopic Studymentioning

confidence: 99%

Polymorphism for a novel phosphoramidate; NMR and X-ray crystallography

et al. 2010

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New phosphoramidates with formula 3-NC 5 H 4 C(O)NHP(O)XY (X=Y=Cl (1), X=Y=NH-C(CH 3 ) 3 (2a,2b), X=Y=N(C 4 H 9 ) 2 (3), X=Cl, Y=N(C 2 H 5 ) 2 (4) were synthesized and characterized by IR, 1 H-, 13 C-, 31 P-NMR spectroscopy and CHN elemental analysis. Surprisingly, the reaction of compound 2a with LaCl 3 , 7H 2 O in 3:1 M ratio leads to a polymorph of this compound (2b). NMR spectra indicate that 2 J(PNH amide ) in 2b (7.0 Hz) is very much greater than in 2a (4.1 Hz), while d( 31 P) values are identical for both of them. In IR spectra, t(P=O) is weaker but t(C=O) is stronger in 2a than in 2b. The structures of 2a, 2b were determined by X-ray crystallography. These compounds form centrosymmetric dimers via two intermolecular P=O……H-N hydrogen bonds. Strong intermolecular N-H…N, N-H…O and weak C-H…O hydrogen bonds lead to a three-dimensional polymeric cluster in the 2a while intermolecular strong N-H……N and weak C-H……O hydrogen bonds form a two-dimensional polymeric chain in 2b.

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“…It must be noted that several parameters such as solvent, certain impurities or additives, concentration, temperature, the geometry of covalent bonds, and the stirring conditions [36,37], affect the formation of a polymorph. Here, SnCl 2 (CH 3 ) 2 acts as an additive and helps in the formation of polymorph 6a.…”

Section: Spectroscopic Studymentioning

confidence: 99%