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Sousa EGRD, Carvalho EMD, San Gil RADS, Santos TCD, Borré LB, Santos-Filho OA, Ellena J. Solution and Solid State Nuclear Magnetic Resonance Spectroscopic Characterization of Efavirenz. J Pharm Sci 2016; 105:2656-2664. [PMID: 26886313 DOI: 10.1016/j.xphs.2015.10.006] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022]
Abstract
Samples of efavirenz (EFZ) were evaluated to investigate the influence of the micronization process on EFZ stability. A combination of X-ray diffraction, thermal analysis, FTIR, observations of isotropic chemical shifts of (1)H in distinct solvents, their temperature dependence and spin-lattice relaxation time constants (T1), solution (1D and 2D) (13)C nuclear magnetic resonance (NMR), and solid-state (13)C NMR (CPMAS NMR) provides valuable structural information and structural elucidation of micronized EFZ and heptane-recrystallized polymorphs (EFZ/HEPT). This study revealed that the micronization process did not affect the EFZ crystalline structure. It was observed that the structure of EFZ/HEPT is in the same form as that obtained from ethyl acetate/hexane, as shown in the literature. A comparison of the solid-state NMR spectra revealed discrepancies regarding the assignments of some carbons published in the literature that have been resolved.
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Affiliation(s)
- Eduardo Gomes Rodrigues de Sousa
- Fundação Oswaldo Cruz, FIOCRUZ/Farmanguinhos, Rua Sizenando Nabuco, 100, 21041-250 RJ, Brazil; Universidade Federal do Rio de Janeiro, Instituto de Química, Av. Athos da Silveira Ramos 149, bl.A, s.605, Ilha do Fundão, 21941-909 RJ, Brazil
| | | | - Rosane Aguiar da Silva San Gil
- Universidade Federal do Rio de Janeiro, Instituto de Química, Av. Athos da Silveira Ramos 149, bl.A, s.605, Ilha do Fundão, 21941-909 RJ, Brazil; Universidade Federal do Rio de Janeiro, Instituto de Pesquisas de Produtos Naturais, RJ, Brazil.
| | | | - Leandro Bandeira Borré
- Universidade Federal do Rio de Janeiro, Instituto de Química, Av. Athos da Silveira Ramos 149, bl.A, s.605, Ilha do Fundão, 21941-909 RJ, Brazil
| | | | - Javier Ellena
- Universidade de São Paulo, Instituto de Física de São Carlos, CP 369, 13560-970 São Carlos, SP, Brazil
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Wandas M, Talik Z. Theoretical and experimental NMR data of 3,5-dinitro-2-(2-phenylhydrazinyl)pyridine and of its 4- and 6-methyl derivatives. J Mol Struct 2013. [DOI: 10.1016/j.molstruc.2013.03.052] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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