Nanosize effect of clay mineral nanoparticles on the drug diffusion processes in polyurethane nanocomposite hydrogels

Abstract

Abstract. Studies of swelling and release of naproxen sodium (NAP) solution by polyurethane nanocomposite hydrogels containing Cloisite 30B (organically modified montmorillonite (OMMT)) have been performed. Polyurethane nanocomposite hydrogels are hybrid, nontoxic biomaterials with unique swelling and release properties in comparison with unmodified hydrogels. These features enable to use nanocomposite hydrogels as a modern wound dressing. The presence of nanoparticles significantly improves the swelling. On the other hand, their presence hinders drug diffusion from polymer matrix and consequently causes delay of the drug release. The kinetics of swelling and release were carefully analyzed using the Korsmeyer-Peppas and the modified Hopfenberg models. The models were fitted to precise experimental data allowing accurate quantitative and qualitative analysis. We observed that 0.5% admixture of nanoparticles (Cloisite 30B) is the best concentration for hydrogel swelling properties. The release process was studied using fluorescence excitation spectra of NAP. Furthermore, we studied swelling hysteresis; polymer chains have not been destroyed after the swelling and part of swelled solution with active substances which remained absorbed in the polymer matrix after the drying process. We have found that the amount of solution with NAP remained in the nanocomposite matrix is greater than in pure hydrogel, as a consequence of NAP-OMMT interactions (nanosize effect).

Transport of paracetamol in swellable and relaxing polyurethane nanocomposite hydrogels

“…In our previous paper [16], we demonstrated the nanosize effect of the nanofiller on the kinetics of the swelling and release of naproxen sodium from polyurethane nanocomposite hydrogels with two different weights of poly(ethylene oxide) doped with various amount of Cloisite® 30B. It was shown that the presence of nanoparticles improves the swelling and also hinders drug diffusion from polymer matrix and consequently slows down the drug release.…”

“…In our previous paper [16], we investigated the swelling and release of naproxen sodium from polyurethane nanocomposite hydrogels with two different molecular weight of PEG, doped with various amounts of nanofiller-organically modified montmorillonite with quaternary ammonium salt (Cloisite® 30B). In particular, we examined the influence of this nanofiller on the kinetics of both processes.…”

“…In paper [16] the X-ray diffraction technique was used to determine the structure of the PU/PEG nanocomposite materials. For nanocomposite samples PU/PEG 4000 with 0.5% and 1% admixtures of clay mineral any diffraction peaks are not observed, what proves existence of only exfoliated structure of nanocomposites, in which the individual clay layers are separated in a continuous polymer matrix.…”

“…The thermoporometry measurements by means of DSC technique have also been taken to determine the pores sizes in hydrogel nanocomposites [16]. From the solidification thermograms we obtained that in the case of PU/PEG 4000/Cloisite® 30B materials only one temperature peak was observed, what corresponds to only one size of pores.…”

“…In this article, we present a description of hydrogel swelling process and release of the active substance-paracetamol (PAR) from a hydrogel polyurethane matrix doped with Cloisite® 30B. We used the polyurethane hydrogel with the optimal proportion of polyurethane elastic segments (PU/PEG 4000) (see [16]), and we studied the influence of various admixtures of clay nanoparticles (Cloisite® 30B) on swelling and release processes. The kinetics of both these processes were also accurately analyzed.…”