Crystal Structure of Levofloxacin Anhydrates: A High-Temperature Powder X-ray Diffraction Study Versus Crystal Structure Prediction

Autor(es)

Freitas, Jennifer T. J. ^[1] ; de Melo, Cristiane C. ^{[1, 2]} ; Viana, Olimpia M. M. S. ^[1] ; Ferreira, Fabio F. ^[3] ; Doriguetto, Antonio C. ^{[1, 2]}

Afiliação do(s) autor(es)

^[1] Univ Fed Alfenas, Fac Pharmaceut Sci, Rua Gabriel Monteiro da Silva 700, BR-37130000 Alfenas, MG - Brazil

^[2] Univ Fed Alfenas, Inst Chem, Rua Gabriel Monteiro da Silva 700, BR-37130000 Alfenas, MG - Brazil

^[3] Fed Univ ABC UFABC, Ctr Nat & Human Sci CCNH, Av Estados 5001, BR-09210580 Santo Andre, SP - Brazil

• Tipo de documento: Artigo Científico
• Fonte: Crystal Growth & Design; v. 18, n. 6, p. 3558-3568, JUN 2018.
• Citações Web of Science: 3

Resumo

Levofloxacin, the levo-isomer of the antibiotic ofloxacin, can crystallize into two different hydrate forms, the monohydrate and the hemihydrate. Although these forms are well characterized, little is known about their anhydrous structures besides the study of Singh and Thakur using crystal structure prediction. In order to solve this issue, this paper proposes the use of high-temperature powder X-ray diffraction to determine the anhydrous structures of the levofloxacin forms termed in the literature as alpha and gamma, herein obtained by heating of the levofloxacin monohydrate and hemihydrate, respectively. These are the first levofloxacin anhydrates whose structures could be solved. To support our results, the dehydration process has been also evaluated by means of differential scanning calorimetry, thermogravimetric analysis, and hot-stage polarized microscopy. The resulting X-ray structures differ from the ones reported as the best-predicted although the predicted work had solution, predicted similar structures as lower ranked solutions. (AU)

• Processo FAPESP: 15/26233-7 - Síntese e caracterização estrutural de cocristais para aplicações em protetores solares e antioxidantes de uso tópico
• Beneficiário: Fabio Furlan Ferreira
• Modalidade de apoio: Auxílio à Pesquisa - Regular