Host-guest paracetamol/cyclodextrin complex formation evaluated from coupled diffusion measurements. (October 2021)

• Record Type: Journal Article
• Authors: Ribeiro, Ana C.F.; Musilová, Lenka; Mráček, Aleš; Cabral, Ana M.T.D.P.V.; Ana Santos, Maria; Cabral, Inês; Esteso, Miguel A.; Valente, Artur J.M.; Leaist, Derek
• Is Part Of: Journal of chemical thermodynamics. Volume 161(2021)
• Publication Date: 2021-10
• Subjects: Cyclodextrin -- Diffusion -- Paracetamol -- Solutions -- Transport properties; Thermodynamics -- Periodicals; Thermochemistry -- Periodicals; Thermodynamique -- Périodiques; Thermochimie -- Périodiques; Thermochemistry; Thermodynamics; Periodicals; 541.369
• DOI: 10.1016/j.jct.2021.106551
• Languages: English
• ISSNs: 0021-9614

Abstract

Highlights: Ternary mutual diffusion coefficients of aqueous paracetamol (HPA) plus β-cyclodextrin (β-CD) (2) solutions. Coupled diffusion as indicated by cross-diffusion coefficients. Estimation of the association constant k = 27 for 1:1 (HPA):(β-CD) complex from diffusion data. Abstract: Ternary mutual diffusion coefficients ( D 11, D 22, D 12 and D 21 ) measured by the Taylor dispersion method are reported for aqueous solutions of paracetamol (1) in the presence of β-cyclodextrin (β-CD) (2) at 298.15 K and solute concentrations up to 0.050 (mol dm −3 ). The diffusion of paracetamol and β-CD is coupled, as indicated by non-zero values of the cross-diffusion coefficients, D 12 and D 21 measuring interactions between the fluxes of the drug and the carbohydrate. The measured ternary diffusion coefficients are in close agreement with the diffusion coefficients predicted by a model assuming a 1:1 (paracetamol):(β-CD) complex. The association constant K = 27 (mol −1 dm 3 ) for the formation of the complex was estimated from the diffusion data.