Polymorphism in Sulfonamides

Yang, Shiu Shiang; Guillory, J. Keith

doi:10.1002/jps.2600610104

Cited by 135 publications

(80 citation statements)

References 17 publications

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“…According to Zhang et al (24), the kinetics of conversion of the metastable to stable form of SMZ in the solid state is so slow that the metastable form does not convert back to the stable one at room temperature. SDM and SDZ do not present polymorphism, and the PXRD patterns recorded for this article correspond to the unique PXRD patterns previously published (25). The PXRD pattern of PVP presents a diffuse halo characteristic of an amorphous material.…”

Section: Stability Testing Of Amorphous Dispersionssupporting

confidence: 85%

“…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: 85%

Section: Introductionmentioning

confidence: 99%

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

Caron

Tajber

et al. 2013

AAPS PharmSciTech

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“…5,2003 Since ∆C p cannot be easy experimentally determined, one of the following assumptions has to be made: (a) ∆C p is negligible and can be considered zero or (b) ∆C p may be approximated to the entropy of fusion, ∆ fus S. The simplified equation is: 12 There are only a few values of enthalpy and entropy of fusion reported in the literature, and they have been obtained by differential thermal analysis (DTA), a semiquantitative method, while the values presented here were obtained by DSC, a quantitative method, the latter being more appropriate for the determination of molar enthalpies of fusion. Our values are generally greater than those reported by Yang and Guillory, 13 and Sunwoo and Eisen, 14 but for SD and SMR, they are very similar to those reported by Maury et al 15 Since the ideal solubility depends on the melting point and the enthalpy of fusion, it is important to know how these properties vary among the various sulfonamides. From Table 2 it can be seen that T fus decreases in the order SD > SMR > STL > SMT > SP > SCM > SMX > SA, and that the enthalpy of fusion decreases in the order SD > SMR > SP > SMT > SMX > STL > SCM > SA.…”

supporting

confidence: 87%

Thermodynamic study of the solubility of some sulfonamides in cyclohexane

Martínez¹,

Ávila²,

Gómez³

2003

J. Braz. Chem. Soc.

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As variações nas funções termodinâmicas energia de Gibbs, entalpia e entropia para os processos de solução de uma série de sulfonamidas em cicloexano foram determinadas nas temperaturas de 20,0 a 40,0 °C. A energia de Gibbs de excesso e os coeficientes de atividade destes solutos também foram calculados. Estes resultados são discutidos em termos de interações soluto-solvente nestes sistemas.The thermodynamic functions Gibbs energy, enthalpy and entropy of solution in cyclohexane, were evaluated from solubility data for a group of sulfonamides over the temperature range from 20.0 to 40.0 °C. The excess Gibbs energy and the activity coefficients of the solutes were also determined. The results are discussed in terms of solute-solvent interactions.

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“…NQR combined with DFT can be also used for structure prediction. An interesting example is the structure of sulfamethizole, known to be able to crystallize in different polymorphic forms [102,103] of which none, even the most stable one, was solved. In a single molecule of sulfamethizole there are four nonequivalent nitrogen positions, but within the NQR experimental resolution five nitrogen positions have been detected [104].…”

Section: Predicted Structurementioning

confidence: 99%

“…exhibit polymorphism. In fact many polymorphs and hundreds of solvates have been discovered for this class of compounds [102].…”

Section: Conformational Polymorphismmentioning

confidence: 99%

Towards Understanding Drugs on the Molecular Level to Design Drugs of Desired Profiles

Latosińska¹,

Latosińska²

2011

Drug Discovery and Development - Present and Future

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Polymorphism in Sulfonamides

Cited by 135 publications

References 17 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

Thermodynamic study of the solubility of some sulfonamides in cyclohexane

Towards Understanding Drugs on the Molecular Level to Design Drugs of Desired Profiles

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