Dependence of Viscosity and Diffusion on <i>β</i>-Cyclodextrin and Chloroquine Diphosphate Interactions

• Main Authors: Lenka Musilová, Aleš Mráček, Eduarda F. G. Azevedo, M. Melia Rodrigo, Artur J. M. Valente, Miguel A. Esteso, Ana C. F. Ribeiro
• Format: Article
• Language: English
• Published: MDPI AG 2021-08-01
• Series: Processes
• Subjects: chloroquine diphosphate; diffusion; drugs; solutions; transport properties
• Online Access: https://www.mdpi.com/2227-9717/9/8/1433

Mutual diffusion coefficients of chloroquine diphosphate (CDP) in aqueous solutions both without and with <i>β</i>-cyclodextrin (<i>β-</i>CD) were measured at concentrations from (0.0000 to 0.0100) mol dm⁻³ and 298.15 K, using the Taylor dispersion technique. Ternary mutual diffusion coefficients (<i>D</i>_ik) measured by the same technique are reported for aqueous CDP + <i>β-</i>CD solutions at 298.15 K. The presence of <i>β</i> CD led to relevant changes in the diffusion process, as showed by nonzero values of the cross-diffusion coefficients, <i>D</i>₁₂ and <i>D</i>₂₁. <i>β-</i>CD concentration gradients produced significant co-current coupled flows of CDP. In addition, the effects of <i>β</i>-CD on the transport of CDP are assessed by comparing the binary diffusion coefficient of aqueous CDP solutions with the main diffusion coefficient (<i>D</i>₁₁) measured for ternary {CDP(1) + <i>β</i>-CD(2)} solutions. These observations are supported by viscosity analysis. All data allow to have a better interpretation on the effect of cyclodextrin on the transport behavior of CDP.