A mechanistic approach for the optimization of loperamide loaded nanocarriers characterization: Diafiltration and mathematical modeling advantages
Catalán-Figueroa, Johanna [Univ Mayor, Ctr Nanotecnol Aplicada, Santiago, Chile]
Fiedler, Jenny L. [Univ Mayor, Ctr Nanotecnol Aplicada, Santiago, Chile]
Boisset, Constanza B.
Jara, Miguel O.
Flores, Mario E.
Morales, Javier O.
Oral bioavailability of loperamide is restricted by its limited absorption in the gastrointestinal tract due to its poor aqueous solubility and its P-glycoprotein (Pgp) substrate characteristic. In addition, ammonium methacrylate copolymers have shown to have mucoadhesive properties, whereas poloxamer 188, has been suggested as a Pgp inhibitor. Thus, in this work, we evaluate conditions that affect physicochemical parameters of ammonium methacrylate/poloxamer 188-based nanocarriers loaded with loperamide hydrochloride. Nanocarriers were synthesized by nanoprecipitation, enhancing loperamide encapsulation efficiency by modifying the aqueous phase to basic pH. The isolation of the non-encapsulated drug fraction from the nanocarriers-incorporated fraction was conducted by centrifugation, ultrafiltration, vacuum filtration and diafiltration. The last method was effective in providing a deeper understanding of drug-nanocarrier loading and interactions by means of modeling the data obtained by it. Through diafiltration, it was determined an encapsulation efficiency of about 93%, from which a 38% +/- 6 was shown to be reversibly (thermodynamic interaction) and a 62% +/- 6 irreversibly (kinetic interaction) bound. Finally, release profiles were assessed through empirical and semi-empirical modeling, showing a biphasic release behavior (burst effect 11.34% and total release at 6 h = 33% +/- 1). Thus, encapsulation efficiency and release profile were shown to have a strong mathematical modeling-based correlation, providing the mechanistic approach presented in this article a solid support for future translational investigations.
Si usted es autor(a) de este documento y NO desea que su publicación tenga acceso público en este repositorio, por favor complete el formulario aquí.