TITLE:
Application of NMR Relaxometry to Study Nanostructured Poly(vinyl alcohol)/MMT/Cephalexin Materials for Use in Drug Delivery Systems
AUTHORS:
Antonio de Pádua Castelo Branco Cunha, Maria Inês Bruno Tavares, Emerson Oliveira da Silva
KEYWORDS:
Polymer, Relaxometry, NMR, Nanotechnology
JOURNAL NAME:
Materials Sciences and Applications,
Vol.7 No.7,
July
27,
2016
ABSTRACT: Polymers containing
nanoparticles dispersed and distributed in the matrix can be used for control
of drug release. In this work, hydrophilic matrix systems were prepared using
poly(vinyl alcohol) and unmodified clay containing the same amount of
cephalexin. The materials were obtained through in situ polymerization and were characterized by the conventional
technique of FTIR and NMR relaxometry, through determination of proton
spin-lattice relaxation time, in order to understand the molecular behavior of
the new materials. The NMR relaxometry data showed that the new materials
containing low quantities of clay (0.25% and 0.75%) and the same amount of
cephalexin (0.5 g) had very good dispersion and distribution of the clay and
drug in the polymer matrix. The combination of clay and cephalexin formed a
more homogenous material with a narrow domain curve and low relaxation values.
The material containing 0.25% clay presented a mixed morphology, with part
exfoliated and part intercalated, as could be seen from the relaxation domain
distribution, which was larger than that for material with 0.75% clay.