Crystallization and Transitions of Sulfamerazine Polymorphs

Zhang, Geoff G. Z.; Gu, Chong‐Hui; Zell, Mark T.; Burkhardt, R.; Munson, Eric J.; Grant, David J.W.

doi:10.1002/jps.10100

Cited by 118 publications

(93 citation statements)

References 25 publications

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“…There are Bragg peaks at 2θ015.7°, 19.2°, 21.3°and 26.6°that were not present in the pattern of the unmilled material. Comparison with results previously published by Zhang et al (24) reveals that the PXRD pattern is characteristic of form II, the stable polymorph of SMZ at room temperature. This shows a remarkable counterintuitive example of stabilisation of material upon milling as the Gibbs free energy of the stable form II is lower than that of the metastable form I (24).…”

Section: Stability Testing Of Amorphous Dispersionssupporting

confidence: 74%

“…Comparison with results previously published by Zhang et al (24) reveals that the PXRD pattern is characteristic of form II, the stable polymorph of SMZ at room temperature. This shows a remarkable counterintuitive example of stabilisation of material upon milling as the Gibbs free energy of the stable form II is lower than that of the metastable form I (24). Such polymorphic transformations upon milling from a metastable/unstable state towards a stable state have been observed in other systems such as indomethacin (33) for example.…”

Section: Stability Testing Of Amorphous Dispersionssupporting

confidence: 74%

“…Despite similar molecular structures, they present several differences. STZ and SMZ present several polymorphs (10,24) while SDM and SDZ present, so far, only one crystalline form (25,26). The excipients selected are polyvinylpyrolidone (PVP) and polyvinyl caprolactam-polyvinyl acetate-polyethylene glycol graft co-polymer (commercially available as Soluplus®).…”

Section: Introductionmentioning

confidence: 99%

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Amorphous Solid Dispersions of Sulfonamide/Soluplus® and Sulfonamide/PVP Prepared by Ball Milling

Caron

Tajber

et al. 2013

AAPS PharmSciTech

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Abstract. The aim of this paper is to investigate the physicochemical properties of binary amorphous dispersions of poorly soluble sulfonamide/polymeric excipient prepared by ball milling. The sulfonamides selected were sulfathiazole (STZ), sulfadimidine (SDM), sulfamerazine (SMZ) and sulfadiazine (SDZ). The excipients were polyvinylpyrrolidone (PVP) and polyvinyl caprolactam-polyvinyl acetate-polyethylene glycol graft co-polymer, commercially known as Soluplus®. Co-milled systems were characterised by powder X-ray diffraction and differential scanning calorimetry. PVP was shown to form amorphous dispersions over a wider composition range than Soluplus® for the four sulfonamides tested. Moreover, amorphous dispersions made with PVP were homogeneous [single glass transition (Tg)], while amorphous dispersions made from Soluplus® were heterogeneous (two Tgs). This behaviour is consistent with the fact that all the sulfonamides tested presented a lower solubility in Soluplus® than in PVP, as evidenced by Flory-Huggins parameters determined. Amorphous dispersions of SDM with Soluplus® could be produced even though SDM does not amorphise alone upon milling and Soluplus® presents Tg at a lower temperature than SDM. Amorphous dispersions of SMZ could be prepared with a lower excipient concentration compared to STZ, SDM and SDZ, which may reflect the one-dimensional H-bonding network in SMZ compared to the 2D or 3D Hbonding network found in the other sulfonamides. Stability tests (60% RH/25°C) revealed that dispersions made with Soluplus® remained dry and powdery compared to those made with PVP that formed a sticky paste in less than 2 weeks, indicating a possible advantage of using Soluplus® in terms of increased physical stability under high humidity storage conditions.

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Section: Stability Testing Of Amorphous Dispersionssupporting

confidence: 74%

Section: Stability Testing Of Amorphous Dispersionssupporting

confidence: 74%

Section: Introductionmentioning

confidence: 99%

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Amorphous Solid Dispersions of Sulfonamide/Soluplus® and Sulfonamide/PVP Prepared by Ball Milling

Caron

Tajber

et al. 2013

AAPS PharmSciTech

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“…The crystallographic phase change involves a ∆H = 26.609 J/g and the sample fusion involves a ∆H = 111.520 J/g. These findings agree with previous studies on polymorphism of sulfonamides 28,29 . After that, in the DTA there are three exothermic peaks at 247.5 ºC, 455.2 ºC and 477.5 ºC that correspond to the decomposition of iron(III) sulfathiazole, as shown in the TGA curve.…”

Section: Thermogravimetric Analysis (Tga) Differential Thermal Analysupporting

confidence: 94%

Synthesis, Physicochemical Analyses, and Antibacterial Activity of the Fe(iii) Salt of 4-Amine-N-2-Thiazolyl-Benzene Sulfonamide

Bordier

Navarro

Cámpora

et al. 2014

J. Chil. Chem. Soc.

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The synthesis and characterization of the Fe(III) complex of sulfathiazole, is presented herein. The compound was prepared by using a conventional precipitation technique, and was characterized by thermogravimetric analysis (TGA), differential thermal (DTA), differential scanning calorimetry (DSC) under oxygen atmosphere, chemical analysis, infrared spectroscopy, powder ray-X diffraction (PXRD), and scanning electron microscopy (SEM). The antibacterial activity of the complex was screened against S. aureus, showing an appreciable activity, compared with the free ligand.

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“…Comminution is also used to improve the uniformity of particle size leading to better mixing properties critical in solid dosage form production (2,3). However, besides reducing the particle size, the milling process is often accompanied by other unintended effects such as changes in morphology (4), crystallinity (5), polymorphism (6), glass transition temperatures (7), chemical stability (8), melting properties (9,10), as well as particle size shifts (11) and specific surface area increase (12) during subsequent post-milling storage. Though undesired, such secondary effects are not well reported and often hard to predict.…”

Section: Introductionmentioning

confidence: 99%

Effect of Milling on DSC Thermogram of Excipient Adipic Acid

Kwek

Yuen

et al. 2010

AAPS PharmSciTech

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Abstract. The purpose of this research was to investigate why and how mechanical milling results in an unexpected shift in differential scanning calorimetry (DSC) measured fusion enthalpy (∆ fus H) and melting point (T m ) of adipic acid, a pharmaceutical excipient. Hyper differential scanning calorimetry (hyper-DSC) was used to characterize adipic acid before and after ball-milling. An experimental study was conducted to evaluate previous postulations such as electrostatic charging using the Faraday cage method, crystallinity loss using powder X-ray diffraction (PXRD), thermal annealing using DSC, impurities removal using thermal gravimetric analysis (TGA) and Karl Fischer titration. DSC thermograms showed that after milling, the values of ∆ fus H and T m were increased by approximately 9% and 5 K, respectively. Previous suggestions of increased electrostatic attraction, change in particle size distribution, and thermal annealing during measurements did not explain the differences. Instead, theoretical analysis and experimental findings suggested that the residual solvent (water) plays a key role. Water entrapped as inclusions inside adipic acid during solution crystallization was partially evaporated by localized heating at the cleaved surfaces during milling. The correlation between the removal of water and melting properties measured was shown via drying and crystallization experiments. These findings show that milling can reduce residual solvent content and causes a shift in DSC results.

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Crystallization and Transitions of Sulfamerazine Polymorphs

Cited by 118 publications

References 25 publications

Amorphous Solid Dispersions of Sulfonamide/Soluplus® and Sulfonamide/PVP Prepared by Ball Milling

Amorphous Solid Dispersions of Sulfonamide/Soluplus® and Sulfonamide/PVP Prepared by Ball Milling

Synthesis, Physicochemical Analyses, and Antibacterial Activity of the Fe(iii) Salt of 4-Amine-N-2-Thiazolyl-Benzene Sulfonamide

Effect of Milling on DSC Thermogram of Excipient Adipic Acid

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