| Full text | |
| Author(s): |
Martins, Felipe T.
[1]
;
Legendre, Alexandre O.
[2]
;
Honorato, Sara B.
[3]
;
Ayala, Alejandro P.
[3]
;
Doriguetto, Antonio C.
[2]
;
Ellena, Javier
[1]
Total Authors: 6
|
| Affiliation: | [1] Univ Sao Paulo, Inst Fis Sao Carlos, BR-13560970 Sao Paulo - Brazil
[2] Univ Fed Alfenas, Dept Ciencias Exatas, BR-37130000 Alfenas, MG - Brazil
[3] Univ Fed Ceara, Dept Fis, BR-60455970 Fortaleza, Ceara - Brazil
Total Affiliations: 3
|
| Document type: | Journal article |
| Source: | Crystal Growth & Design; v. 10, n. 4, p. 1885-1891, APR 2010. |
| Web of Science Citations: | 10 |
| Abstract | |
For the first time, crystals of suitable size for X-ray diffractometry structure determination (Dian important anti-HI V drug were prepared under solvothermal conditions. In this study, the crystal structure of didanosine (2',3'-dideoxyinosine, ddI) in the form of a hydrate was determined using single-crystal X-ray diffractometry. Powder X-ray diffraction analysis revealed that the solid-state phase of the drug incorporated into pharmaceutical solid dosage forms is isostructural to the solvothermally prepared ddI material, even though they do not exhibit an identical chemical composition due to different water fractions occupying hydrophobic channels formed within the crystal lattice. Two ddI conformers are present in the structure, in agreement with a previous structure elucidation attempt. Concerning the keto enol equilibrium of ddI, our crystal data and vibrational characterizations by Fourier transform infrared (FTIR) and FT-Raman spectroscopy techniques were conclusive to state that both conformers exist in the keto form, contrary to solid-state NMR spectroscopic assignments that suggested ddI molecules occur as enol tautomers. In addition, characterizations by thermal (differential scanning calorimetry) and spectroscopic techniques allowed us to understand the structural similarities and the differences related to the hydration pattern of the nonstoichiometric hydrates. (AU) | |
| FAPESP's process: | 09/14705-0 - Solid state characterization of anti-HIV drugs: rational design of new crystalline forms |
| Grantee: | Javier Alcides Ellena |
| Support Opportunities: | Regular Research Grants |
| FAPESP's process: | 07/07185-5 - Screening, characterization and evaluation for novel crystal forms from antiretroviral and antineoplastic drugs |
| Grantee: | Felipe Terra Martins |
| Support Opportunities: | Scholarships in Brazil - Doctorate |