Relevance of silica surface morphology in Ampyra adsorption. Insights from quantum chemical calculations

GRAU, E. NOSEDA; ROMÁN, G.; COMPAÑY, A. DÍAZ; BRIZUELA, G.; JUAN, A.; SIMONETTI, S.

RSC Advances

RSC

Año: 2019 vol. 9 p. 4415 - 4421

Theoretical calculations are performed using the Vienna Ab-initio simulation package (VASP) to understandthe mechanisms that control the adsorption of Ampyra drug on the different crystallographic planes of bcristobalite:the hydroxylated (111) and (100) surfaces. The Ampyra-silica interaction is most favored on the(100) surface where the entire ring of the molecule interacts with the surface while on the (111) face, lesserexchange and fewer non-polar atoms are involved. Calculations show that the interactions mainly occur atthe interface between the Ampyra and the closest silanol groups, according to the formation of the Hbondinginteractions. The results indicate that the H-bonds have an important influence on theadsorption of the Ampyra. In consequence, adsorption on the (111) surface is observed to a lesser extentthan on the (100) surface according the smaller hydroxyl density.