Polymorphism, pseudopolymorphism, and amorphism of peracetylated α-, β-, and γ-cyclodextrins

• Published in: Journal of pharmaceutical and biomedical analysis 2006-06, Vol.41 (4), p.1205-1211
• Main Authors: Bettinetti, Giampiero, Sorrenti, Milena, Catenacci, Laura, Ferrari, Franca, Rossi, Silvia
• Format: Article
• Language: English
• Subjects: Analysis; Analytical, structural and metabolic biochemistry; Biological and medical sciences; Calorimetry, Differential Scanning; Crystallography, X-Ray - methods; Cyclodextrins - chemistry; Cyclodextrins - classification; Cyclodextrins - isolation & purification; Differential scanning calorimetry; Fourier transform infrared spectroscopy; Fundamental and applied biological sciences. Psychology; General pharmacology; Medical sciences; Microscopic analysis; Peracetylated cyclodextrins solid-state forms; Pharmacology. Drug treatments; Powder X-ray diffractometry; Spectroscopy, Fourier Transform Infrared - methods; Thermogravimetric analysis; Thermogravimetry - methods
• ISSN: 0731-7085; 1873-264X
• DOI: 10.1016/j.jpba.2006.03.008

Polymorphism, pseudopolymorphism, and amorphism of hexakis(2,3,6-tri- O-acetyl)-α-cyclodextrin (TAαCyD), heptakis(2,3,6-tri- O-acetyl)-β-cyclodextrin (TAβCyD), and octakis(2,3,6-tri- O-acetyl)-γ-cyclodextrin (TAγCyD) were investigated using differential scanning calorimetry (DSC), thermogravimetric analysis (TGA), powder X-ray diffractometry (XRPD), Fourier transform infrared spectroscopy (FTIR) and optical microscopy. An anhydrous and a bi-hydrate crystalline forms of TAαCyD, two monotropic anhydrous polymorphs and three pseudopolymorphs (i.e. methanolate, hydrate, and isopropanolate-hydrate) of TAβCyD, as well as two monotropic anhydrous polymorphs and isostructural pseudopolymorphs (e.g. hydrate and isopropanolate-hydrate) of TAγCyD were isolated and characterized. The amorphous forms of each TACyD were also obtained. Thermal data for desolvation of TAαCyD·2H 2O and TAβCyD·CH 3OH were reconciled with their crystal packing features. Melting temperatures and enthalpies of the crystalline forms of each TACyD can be referred to for possible solid-state interactions with drugs.