A Spectroscopic and Crystallographic Study of Polymorphism in an Aza‐Steroid

Wenslow, Robert M.; Baum, M.; Ball, Richard G.; McCauley, James A.; Varsolona, Richard J.

doi:10.1002/1520-6017(200010)89:10<1271::aid-jps5>3.0.co;2-6

Cited by 43 publications

(27 citation statements)

References 4 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…For these reasons, a number of studies on the estimation of transition temperature have been reported until now. [9][10][11][12][13][14][15] In these studies, transition temperature has been estimated by linear extrapolation of van't Hoff plots (logarithmic solubility versus reciprocal of absolute temperature plots) for each polymorph; the temperature at which these extrapolated lines intersect is the transition temperature.…”

mentioning

confidence: 79%

See 1 more Smart Citation

A Novel Method for Estimation of Transition Temperature for Polymorphic Pairs in Pharmaceuticals Using Heat of Solution and Solubility Data.

Urakami

Shono

Higashi

et al. 2002

CHEMICAL & PHARMACEUTICAL BULLETIN

View full text Add to dashboard Cite

mentioning

confidence: 79%

“…In previous studies, [9][10][11][12][13][14][15] this equation has been widely applied for the estimation of transition temperature for the enantiotropic polymorphic pairs. At a temperature of T 1 , the logarithmic solubilities of Form A and B in a polymorphic pair are written as Eqs.…”

Section: Theoreticalmentioning

confidence: 99%

A Novel Method for Estimation of Transition Temperature for Polymorphic Pairs in Pharmaceuticals Using Heat of Solution and Solubility Data.

Urakami

Shono

Higashi

et al. 2002

CHEMICAL & PHARMACEUTICAL BULLETIN

View full text Add to dashboard Cite

“…According to the literature, finasteride exists in three or four crystalline polymorphic forms [5][6][7][8][9][10][11][12][13][14][15][16][17][18] and many solvates. 6,8,9,11,12,14,15,[19][20][21] All of these forms have been characterized by the methods chosen from among FTIR, differential scanning calorimetry (DSC), X-ray powder diffraction (XRPD), 13 C cross-polarization magic angle spinning (CP-MAS) nuclear magnetic resonance (NMR), and single-crystal X-ray diffraction (SCXRD).…”

Section: Introductionmentioning

confidence: 99%

“…6,8,9,11,12,14,15,[19][20][21] All of these forms have been characterized by the methods chosen from among FTIR, differential scanning calorimetry (DSC), X-ray powder diffraction (XRPD), 13 C cross-polarization magic angle spinning (CP-MAS) nuclear magnetic resonance (NMR), and single-crystal X-ray diffraction (SCXRD). The polymorphic form I was characterized by FTIR, [5][6][7][8]10 DSC, 5,7,10,11,[13][14][15]18 and XRPD 5,10,13,14 techniques. Moreover, the 13 C CP-MAS NMR 7,8,11,12 and SCXRD data 6,7 showed that in the crystallographic asymmetric unit only one molecule of finasteride is present.…”

Section: Introductionmentioning

confidence: 99%

Comprehensive Spectroscopic Characterization of Finasteride Polymorphic Forms. Does the Form X Exist?

Frelek

Górecki

Dziedzic

et al. 2015

Journal of Pharmaceutical Sciences

View full text Add to dashboard Cite

“…1,5,6) In the conformational study for drug formulation, solid-state NMR has intrinsic advantages as follows: 1) This method is less destructive so that the sample probably remains in the original conformation. 2) It is more possible to avoid the interference of coexistent excipients with evaluation because some chemical shifts of an active ingredient, which mostly has some unsaturated bonds, likely separate from those of excipients used commonly for solid dosage form, many of which have no unsaturated bonds.…”

mentioning

confidence: 99%

Investigation of Intermolecular Interaction in Molecular Complex of Tryptamine and Benzoic Acid by Solid-State 2D NMR

Terakita

Matsunaga

Ueda

et al. 2004

CHEMICAL & PHARMACEUTICAL BULLETIN

View full text Add to dashboard Cite

In the course of drug development, it is a great concern to understand an intermolecular interaction, such as hydrogen bonding and electrostatic interaction, between an active ingredient and excipients in a drug formulation, because the interaction may affect the physicochemical properties of the formulation, such as polymorphism, 1) chemical reactivity, 2,3) and dissolution.4) The influence of the interaction can be either preferable to the quality of formulation or not. 3,4) Therefore there is possibility to design drug formulation for better quality by utilizing or avoiding the intermolecular interaction intentionally. For such an intentional formulation design, the compatibility testing with various combinations of components is usually necessary to investigate whether an active ingredient interacts with any excipients or not, and reveal the mechanism and influence of the interaction on the quality if any. Although the analytical method such as powder X-ray diffraction (PXRD) and IR could be often used for such a research, it would be difficult to evaluate the interaction in drug formulation containing some components since the coexistent matrix would complicate the results.Recently the solid-state NMR technique has been commonly used for research on the drug conformation as represented by polymorphism studies. 1,5,6) In the conformational study for drug formulation, solid-state NMR has intrinsic advantages as follows: 1) This method is less destructive so that the sample probably remains in the original conformation. 2) It is more possible to avoid the interference of coexistent excipients with evaluation because some chemical shifts of an active ingredient, which mostly has some unsaturated bonds, likely separate from those of excipients used commonly for solid dosage form, many of which have no unsaturated bonds. In addition, 2D heteronuclear-correlation (HETCOR) method is expected to provide still more information about the geometry of molecules than 1D proton or carbon solidstate NMR does. 7,8) Since the heteronuclear dipolar coupling just depends on the distance between the nuclei, the correlated peak intensity of HETCOR spectrum correlate mainly with the distance of nuclei.8-10) Therefore 1D and 2D solidstate NMR can be one of powerful methods for investigation of intermolecular interaction in formulation. In order to verify the usefulness of the solid-state NMR technique for the interaction study, we measured 1D 13 C CP/MAS NMR and 2D HETCOR spectra of the molecular complex of tryptamine and benzoic acid, found by Koshima et al.,11,12) as a model sample. Although the crystal structure of the complex has not been determined, the complex was predicted to have hydrogen bonding and/or electrostatic interaction from the results of X-ray crystallographic analysis for other analogous complexes. Since such interactions could be generated in drug formulation and its structure was unknown, it was selected as a model sample. ExperimentalMaterials Tryptamine was purchased from Tokyo Kasei Kogyo Co., Ltd. Benzoic...

show abstract

A Spectroscopic and Crystallographic Study of Polymorphism in an Aza‐Steroid

Cited by 43 publications

References 4 publications

A Novel Method for Estimation of Transition Temperature for Polymorphic Pairs in Pharmaceuticals Using Heat of Solution and Solubility Data.

A Novel Method for Estimation of Transition Temperature for Polymorphic Pairs in Pharmaceuticals Using Heat of Solution and Solubility Data.

Comprehensive Spectroscopic Characterization of Finasteride Polymorphic Forms. Does the Form X Exist?

Investigation of Intermolecular Interaction in Molecular Complex of Tryptamine and Benzoic Acid by Solid-State 2D NMR

Contact Info

Product

Resources

About