Drug Release from Coadsorbates of Nonionic Surfactants with Parabenes on Porous Silica Supports

Abstract

Parabenes are coadsorbed from aqueous solutions with nonionic surfactants (polyoxyethylene-nonyl-phenols) on silica surfaces. Rate and extend of para-bene desorption from corresponding coadsorbates on porous silica were shown to be dependent on the influence of structure and pore size (in the mesopore range 2–10 nm) of the silica supports, the alkyl chain length of the parabenes, the structure of the POE-surfactant, and the adsorption equilibria established during the drug loading of the supports. The consequences of coadsorption on drug release modification are discussed.