Evaluation of Nevirapine Release Kinetics from Polycaprolactone Hybrids

Abstract

The Nevirapine (NVP)/Polycaprolactone (PCL)/Nanoparticles hybrids systems have been developed as a potential platform for drug delivery, by solvent cast, as thin films. NVP, an antiretroviral drug, was included within PCL matrix containing three types of nanoparticles: an organoclay layered silicate Viscogel S7® (3% w/w), hydro-philic silica oxide particles Aerosil® A20 (0.25% w/w) and titanium dioxide particles (0.25% w/w). These systems were characterized by X-ray diffraction (XRD), Fouri-er-transform infrared spectroscopy (FTIR), low-field nuclear magnetic resonance (NMR), ultraviolet-visible spectroscopy (UV), in-vitro dissolution testing and drug release mechanism kinetics. The PCL crystallization was affected by NVP incorpora-tion, modifying its semi-crystalline structure to a less ordered structure. When na-noparticles and NVP were added, the T 1 H values increased, for PCL, PCL/S7, PCL/ SiO 2 and PCL/TiO 2 hybrids, suggesting that its addition produced a new material, with less molecular mobility, due to the new intermolecular interactions formation. It can consider a structure formation among the PCL chains, nanoparticles and NVP, with strong forces in the PCL/SiO 2 /NVP system. The amount of NVP included was around 1.5 ± 0.03 mg/cm 2 . In the in-vitro dissolution test, the PCL/SiO 2 /NVP system released the smallest amount of drug and this result could be attributed to the strong intermolecular interaction between the drug and the PCL/SiO 2 system. Higuchi's model was the mathematical model chosen to treat the release data, since this model presented the highest coefficient correlation (r) value. The drug release probably oc-cur by diffusion through the matrix pores, thus, these materials are suitable for sus-tained release of NVP.