Hibrid nanocomposites ureasyl-poly(ethylene oxide) and layered double hydroxides for drug controlled release

Author(s)

Áddila Gabriela Salgado Corrêa

• Document type: Master's Dissertation
• Press: Araraquara. 2021-08-03.
• Institution: Universidade Estadual Paulista (Unesp). Instituto de Química. Araraquara
• Defense date: 2021-07-22
• Advisor: Sandra Helena Pulcinelli

Abstract

Ureasyl - polyethylene oxide (U-POE), is widely studied in the pharmaceutical area for its simplicity of synthesis, mechanical and thermal resistance, transparency, flexibility, insolubility in water and biocompatibility. This material allows to regulate the rate of drug delivery, to sustain the duration of the therapeutic action and, or to direct the supply of the drug to a specific tissue in a reproducible way and for a specific time period. The purpose of this project was the development of a material formed by the junction of a hybrid matrix ureasyl-poly(ethylene oxide) with POE1900 block molecular weight of 1900 g/ mol (U-POE1900) with nanoparticles of layered double hydroxides MgAl-Cl-LDH, aiming to build diffusion barriers to control drug delivery. The two drugs used were the anti-inflammatory Sodium Diclofenac (SDCF) and the antibiotic Metronidazole (MTZ). The membranes prepared via sol-gel process were characterized and its structure analyzed by X-Ray Diffraction (XRD) and infrared spectroscopy (FT-IR), nanostructure by small-angle X-ray scattering (SAXS) and thermal behavior by thermogravimetric analysis (TG). The intercalation of LDH by POE polymeric chains in both samples containing SDCF and MTZ, as well as the loss of the crystalline characteristics of the polymer after the formation of the products, more significantly for the samples with MTZ, were revealed by XRD. FT-IR results allowed to conclude that only weak interactions between the materials occurred, while SAXS showed that the addition of drug and clay stimulate the increase of the correlation distances, precisely to accommodate these particles inside the matrix. Thermal analyzes showed that the introduction of clay mineral into the sample delayed the drug decomposition to the same temperature as the LDH-matrix. The release profile of SDCF was less dependent on the pH of the diffusional environment compared to the release tests performed with MTZ. The matrices containing the larger amounts of LDH exhibited a slower release profile. Tests performed for U-POE1900-LDH-MTZ showed that the release profile of the MTZ antibiotic is delayed, as long as the membrane is in acidic environments, pH = 1.5 and 4.5. In conclusion, the use of HDL in the U-PEO1900 matrix is interesting as it forms its diffusion barrier at specific pH, and proposes a new hybrid film for topical application. (AU)

• FAPESP's process: 19/06044-6 - Hibrid nanocomposites ureasil-poly(ethylene oxide)/(propylene oxide) and layered double hydroxides for drug controlled release
• Grantee: Addila Gabriela Salgado Correa
• Support Opportunities: Scholarships in Brazil - Master