Title: Characterization and cytotoxicity of a benzocaine inclusion complex
Author: Torres, Liliane Henrique; De Carvalho, Mohana Zorkot; Melo, Patrícia Da Silva; De Paula, Eneida; Saczk, Adelir Aparecida; Pinto, Luciana De Matos Alves
Is part of: JOURNAL OF INCLUSION PHENOMENA AND MACROCYCLIC CHEMISTRY, v. 91, p. 9 - 15
Citation: Torres, Liliane Henrique; De Carvalho, Mohana Zorkot; Melo, Patrícia Da Silva; De Paula, Eneida; Saczk, Adelir Aparecida; Pinto, Luciana De Matos Alves; Characterization and cytotoxicity of a benzocaine inclusion complex. JOURNAL OF INCLUSION PHENOMENA AND MACROCYCLIC CHEMISTRY, v.91, p. 9-15, 2018
Abstract: Benzocaine (BZC), is a local anesthetic widely used in topical formulations as well as in throat pastilles. A disadvantage is that the compound presents low aqueous solubility. The present work describes the preparation and characterization of an inclusion complex between BZC and beta-cyclodextrin (beta-CD), followed by cytotoxicity assays. The association constant (Ka) was calculated using solubility isotherms, at different temperatures, and an HPLC procedure, at room temperature, employing a reverse phase C18 column, with a mobile phase consisting of water/acetonitrile. Ka obtained with solubility isotherms at temperatures of 25, 35, and 45 degrees C were 229.8, 317.1, and 520.3 M-1, respectively. Employing HPLC, Ka was 38.0 M-1. The difference in the Ka value could be explained because HPLC analyses were conducted using organic solvent, which affected the host-guest interaction. Moreover, the continuous flow could have altered the degree of association of the drug with beta-CD. The BZC/CD inclusion complex was characterized using infrared spectroscopy, thermogravimetry, and X-ray diffraction. Analysis showed a good agreement with literature, suggesting that the complex was established. Cytotoxicity assays using fibroblast V79 cells showed that BZC/CD formulation was not cytotoxic, demonstrating its potential to reduce the toxicity of the anesthetic. The assays demonstrated an effective interaction between BZC and CD, and that the inclusion complex was less toxic to V79 cells than the plain BZC, turning it a good alternative to decrease its toxicity when administered to patients.
Keywords: cyclodextrins; drug delivery; inclusion complex;
Subjects: CIENCIAS_BIOLOGICAS; Farmacologia Bioquímica e Molecular;
Funding: The authors thank Centro de Analises e Prospeccao Quimica (CAPQ/UFLA), Departamento de Ciencias do Solo (UFLA), and Laboratorio de Cultura de Celulas (UNICAMP) for the provision of equipment and facilities. M.Z.C. received a fellowship from FAPEMIG, and L.M.A.P. received a fellowship from FAPESP.