Polymorph screening: Influence of solvents on the rate of solvent-mediated polymorphic transformation

Gu, Chong Hui; Young, Victor G.; Grant, David J.W.

doi:10.1002/jps.1137

Cited by 286 publications

(171 citation statements)

References 23 publications

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“…Both the temperature and degree of agitation influence the transformation rate. 22 It was found that in the ethanol-water (3-1 V/V) mixture (Fig. 4 and 8) and in the 2-propanol-water (8-2 V/V) mixture ( Fig.…”

Section: Resultsmentioning

confidence: 99%

Crystallisation of a salt hydrate with a complex solid form landscape

et al. 2017

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Different approaches were utilized to assess the thermodynamic stability relationship between four distinct hemihydrates of sitagliptin L-tartrate (SLT). These phases are true polymorphs, having the same chemical composition and molar ratio of water, but different arrangement in the crystal lattice. The general approaches (Burger and Ramberger rules) have only limited applicability, but indicated a monotropic relationship between Phase 1 and Phase 2. The crystallisation and transformation behaviour of the polymorphs was strongly influenced by the solvent composition. As the stability thereof was found to be solvent-dependent, the application of the van't Hoff plot or the solvent-mediated transformation did not unambiguously reveal the relative stability of the forms. Experiments were carried out in an endeavour to determine the most suitable concentration trajectory for cooling crystallisation of the selected candidate and prevent concomitant crystallisation. The application of in situ monitoring techniques, such as FTIR-ATR and FBRM, offered great potential for process optimization and control.

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Section: Resultsmentioning

confidence: 99%

Crystallisation of a salt hydrate with a complex solid form landscape

et al. 2017

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“…This makes new polymorphs accessible when they would not be with a different choice in solvent. 29 Additionally, solvents can assist the formation of solvates through modulating the aggregation of crystal precursors with solvent inclusion in crystal forms. 28 Further, the Figure 5.…”

Section: Crystallization Processesmentioning

confidence: 99%

Controlling Polymorphism in Pharmaceutical Compounds Using Solution Shearing

Guthrie

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“…The mechanism of modification can be best explained by solvent-solute interactions (20,28). Hydrogen bond formation, between solvent and solute, plays a key role in the formation of different solid-state morphology (19,20,28). Normally, there are three types of solvents used in routine morphology screening.…”

Section: ) C O M P L I E D W I T H D I H Y D R a T E F O R M O F A M mentioning

confidence: 99%

“…However, the above known solidstate morphologies of AQ in correlation with their physicochemical properties have not yet been reported. Therefore, the objective of this study is to evaluate the differences in amodiaquine dihydrochloride solid-state morphology after recrystallizing in various alcoholic solvents (18)(19)(20)(21) and correlate them with their respective physicochemical properties. Methanol, ethanol, and npropanol, which are monohydric alcohols, were selected as recrystallizing solvents due to their increasing series in carbon number and have not been used as pure form for AQ solidstate morphology screening in all previous reports.…”

Section: Introductionmentioning

confidence: 99%

Solid-State Characterization and Interconversion of Recrystallized Amodiaquine Dihydrochloride in Aliphatic Monohydric Alcohols

2015

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Abstract. Amodiaquine dihydrochloride monohydrate (AQ-DM) was obtained by recrystallizing amodiaquine dihydrochloride dihydrate (AQ-DD) in methanol, ethanol, and n-propanol. Solid-state characterization of AQ-DD and AQ-DM was performed using X-ray powder diffractometry, Fourier transform infrared spectroscopy, thermogravimetry, and differential scanning calorimetry. All recrystallized samples were identified as AQ-DM. Crystal habits of AQ-DD and AQ-DM were shown to be needle-like and rhombohedral crystals, respectively. When AQ-DD and AQ-DM were exposed to various relative humidity in dynamic vapor sorption apparatus, no solid-state interconversion was observed. However, AQ-DM showed higher solubility than AQ-DD when exposed to bulk water during solubility study, while excess AQ-DM was directly transformed back to a more stable AQ-DD structure. Heating AQ-DM sample to temperatures ≥190°C induced initial change to metastable amorphous form (AQ-DA) which was rapidly recrystallized to AQ-DD upon ≥80%RH moisture exposure. AQ-DD was able to be recrystallized in alcohols (C1-C3) as AQ-DM solid-state structure. In summary, AQ-DM was shown to have different solubility, moisture and temperature stability, and interconversion pathways when compared to AQ-DD. Thus, when AQ-DM was selected for any pharmaceutical applications, these critical transformation and property differences should be observed and closely monitored.

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Polymorph screening: Influence of solvents on the rate of solvent-mediated polymorphic transformation

Cited by 286 publications

References 23 publications

Crystallisation of a salt hydrate with a complex solid form landscape

Crystallisation of a salt hydrate with a complex solid form landscape

Controlling Polymorphism in Pharmaceutical Compounds Using Solution Shearing

Solid-State Characterization and Interconversion of Recrystallized Amodiaquine Dihydrochloride in Aliphatic Monohydric Alcohols

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