Estimating Relative Stability of Polymorphs by Generation of Configurational Free Energy Phase Diagram

Upadhyay, Pratik P.; Dantuluri, Ajay K.; Kumar, Lokesh; Bansal, Arvind K.

doi:10.1002/jps.23083

Cited by 13 publications

(10 citation statements)

References 24 publications

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“…The relative stability of crystal polymorphs can be estimated from their solubility ( s ) ratio as: Δ G B→A = − RT ln( s B / s A ) where Δ G B→A is the Gibbs free energy for transformation of crystal phase B to phase A. 36 Assuming the change in the observed ZIF-L/ZIF-8 crystal ratio outside and inside the FP cavity is proportional to the change in solubility ratio in each environment, we can make a rudimentary estimate for the cavity-induced relative stabilization of the ZIF-8 form. For the 1 : 28 Zn : Hmeim ratio starting material experiment, this yields an estimated 395 cm −1 stabilization energy.…”

Section: Resultsmentioning

confidence: 99%

Selective crystallization via vibrational strong coupling

Hirai

Ishikawa

Chervy³

et al. 2021

Chem. Sci.

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Section: Resultsmentioning

confidence: 99%

Selective crystallization via vibrational strong coupling

Hirai

Ishikawa

Chervy³

et al. 2021

Chem. Sci.

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“…Crystal kinetics of amorphous solids with respect to their crystalline forms are widely studied by determining the configurational terms, namely, enthalpy ( H conf ), entropy ( S conf ), and free energy ( G conf ). The term C pConf is the difference of heat capacity ( C p ) of amorphous and crystalline forms

\begin{matrix} true \\ right H_{c} ((), T) = Δ H_{m} - \int_{T}^{T_{normalm}} C_{pConf} normald T = Δ H_{m} - K \ln \frac{T_{normalm}}{T} \end{matrix}

\begin{matrix} true \\ right S_{c} ((), T) = Δ S_{m} - \int_{T}^{T_{normalm}} \frac{C_{pConf}}{T} normald T = Δ S_{m} - K ((), \frac{1}{T} - \frac{1}{T_{normalm}}) \end{matrix}

\begin{matrix} true \\ right G_{c} ((), T) = H_{c} - T S_{c} = Δ H_{m} - T Δ S_{m} + K ((), 1 - \frac{T}{T_{normalm}} + \ln \frac{T}{T_{normalm}}) \end{matrix}

The temperature dependence of C pConf can be given by Eq.…”

Section: Methodsmentioning

confidence: 99%

“…The term C pConf is the difference of heat capacity (C p ) of amorphous and crystalline forms. 22,[50][51][52][53]…”

Section: Configurational Free Energy Phase Diagrammentioning

confidence: 99%

“…Yu reported a method to infer thermodynamic stability relationships of polymorphs from melting data. Upadhyay et al reported the use of configurational free energy phase diagram to estimate the relative stability of polymorphic forms. Knowledge of the relationship between the thermodynamic quantities H (enthalpy), G (free energy), S (entropy), and T (temperature) is critical to understand the equilibrium states and phase transition in solid/solution state.…”

Section: Introductionmentioning

confidence: 99%

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Characterization and Thermodynamic Relationship of Three Polymorphs of a Xanthine Oxidase Inhibitor, Febuxostat

Patel

Jagia

Bansal

et al. 2015

Journal of Pharmaceutical Sciences

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“…Subsequently, publications by Bruni, et al reported a new but unstable anhydrous polymorphic modification melting at 102 °C (form X), which gradually transformed to form H. These researchers have also proposed the method for evaluating the purity of H polymorph in the binary mixture of B and H using diffraction scanning calorimetry (DSC) [11][12][13]. The monotropic relationship between Form B and H and stability co-relation between these two had been established by Upadhyay, et al, using configurational free energy phase diagrams [14]. Recently, Pasha, et al have evaluated few crystal forms by recrystallizing nateglinide from solvents as well as aqueous solution of surfactants without proper characterization, interpretation and structure determination [15].…”

Section: Introductionmentioning

confidence: 99%

Exploring Structural Aspects of Nateglinide Polymorphs Using Powder X-Ray Diffraction

Goyal

Rani

Chadha

2017

Int J Pharm Pharm Sci

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Objective: The present manuscript highlights the structural aspects of some polymorphic forms of nateglinide using powder x-ray diffraction (PXRD) pattern.Methods: All the polymorphic forms were isolated as microcrystalline powder, therefore, powder diffraction patterns was used as a tool to determine the crystal structure. For this, Reflux Plus module of BIOVIA Material Studio software was used. Polymorph prediction (PP) and crystal morphology analysis were performed to estimate the global minimum in lattice energy landscape and morphologically important (M. I.) facets, respectively. Besides this, to investigate the behavior of polymorphs in solution phase, in vitro studies (enthalpy of solution, solubility, intrinsic dissolution rate) were also performed. Results:A new form MS was prepared and characterized. The Form H, B, MS and S were found to exist in space group P-1, C2, P-4 and P-42C, respectively. These crystal structures were found to lie on local minima in crystal energy landscape. The stability ranking of nateglinide polymorphs follows the order: Form MS

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Estimating Relative Stability of Polymorphs by Generation of Configurational Free Energy Phase Diagram

Cited by 13 publications

References 24 publications

Selective crystallization via vibrational strong coupling

Selective crystallization via vibrational strong coupling

Characterization and Thermodynamic Relationship of Three Polymorphs of a Xanthine Oxidase Inhibitor, Febuxostat

Exploring Structural Aspects of Nateglinide Polymorphs Using Powder X-Ray Diffraction

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