Andressa R Prado1, Fabiano Yokaichiya2, Margareth Kazuyo Kobayashi Dias Franco3, Camila Morais Gonçalves da Silva1, Laura Oliveira-Nascimento1,4, Michelle Franz-Montan5, Maria C Volpato5, Luís F Cabeça6, Eneida de Paula1. 1. Biochemistry and Tissue Biology Department, Biology Institute, University of Campinas (Unicamp), Campinas, SP, Brazil. 2. Department Quantum Phenomena in Novel Materials, Helmholtz-Zentrum Berlin für Materialien und Energie GmbH, Berlin, Germany. 3. Institute for Energetic and Nuclear Research (IPEN)/Multipurpose Brazilian Reactor, Cidade Universitária Armando Salles de Oliveira, São Paulo, SP, Brazil. 4. Faculty of Pharmaceutical Sciences, University of Campinas (Unicamp), Campinas, SP, Brazil. 5. Department of Physiological Sciences, Piracicaba Dental School, University of Campinas (Unicamp), Piracicaba, SP, Brazil. 6. Technologic Federal University of Parana, Londrina, PR, Brazil.
Abstract
OBJECTIVES: Oxethazaine (OXZ) is one of the few local anaesthetics that provides analgesia at low pH, but presents poor solubility, cytotoxicity and no parenteral formulations. To address these issues, we aimed to prepare OXZ host-guest inclusion complex with hydroxypropyl-beta-cyclodextrin (HP-β-CD). METHODS: The inclusion complex was formed by co-solubilization, followed by a job plot analysis to determine stoichiometry of complexation and dialysis equilibrium analysis (based on UV/VIS absorption and fluorescence profiles of OXZ). Complex formation was confirmed by phase-solubility data, X-ray, Scanning Electron Microscopy and DOSY-1 H-NMR experiments. In vitro cytotoxicity was analysed by MTT test in 3T3 fibroblasts. In vivo analgesia was tested by Von Frey test (inflammatory wounds - rats). KEY FINDINGS: Oxethazaine complexed (1 : 1 molar ratio) with HP-β-CD, as indicated by loss of OZX crystalline structure (X-ray) and strong host: guest interaction (NMR, K = 198/M), besides increased solubility. In vitro cell survival improved with the complex (IC50 OXZ = 28.9 μm, OXZ : HP-β-CD = 57.8 μm). In addition, the complex (0.1% OXZ) promoted in vivo analgesia for the same time that 2% lidocaine/epinephrine did. CONCLUSION: Our results show that complexation improved physicochemical and biological properties of OXZ, allowing its application to inflamed tissues by parenteral routes.
OBJECTIVES:Oxethazaine (OXZ) is one of the few local anaesthetics that provides analgesia at low pH, but presents poor solubility, cytotoxicity and no parenteral formulations. To address these issues, we aimed to prepare OXZ host-guest inclusion complex with hydroxypropyl-beta-cyclodextrin (HP-β-CD). METHODS: The inclusion complex was formed by co-solubilization, followed by a job plot analysis to determine stoichiometry of complexation and dialysis equilibrium analysis (based on UV/VIS absorption and fluorescence profiles of OXZ). Complex formation was confirmed by phase-solubility data, X-ray, Scanning Electron Microscopy and DOSY-1 H-NMR experiments. In vitro cytotoxicity was analysed by MTT test in 3T3 fibroblasts. In vivo analgesia was tested by Von Frey test (inflammatory wounds - rats). KEY FINDINGS:Oxethazaine complexed (1 : 1 molar ratio) with HP-β-CD, as indicated by loss of OZX crystalline structure (X-ray) and strong host: guest interaction (NMR, K = 198/M), besides increased solubility. In vitro cell survival improved with the complex (IC50 OXZ = 28.9 μm, OXZ : HP-β-CD = 57.8 μm). In addition, the complex (0.1% OXZ) promoted in vivo analgesia for the same time that 2% lidocaine/epinephrine did. CONCLUSION: Our results show that complexation improved physicochemical and biological properties of OXZ, allowing its application to inflamed tissues by parenteral routes.
Authors: Verônica Muniz Couto; Laura de Oliveira-Nascimento; Luiz Fernando Cabeça; Danilo Costa Geraldes; Juliana Souza Ribeiro Costa; Karin A Riske; Michelle Franz-Montan; Fabiano Yokaychiya; Margareth K K Dias Franco; Eneida de Paula Journal: Int J Mol Sci Date: 2020-08-10 Impact factor: 5.923