Evaluation of Nevirapine Release Kinetics from Polycaprolactone Hybrids

Mariana S S B Monteiro,Pedro J Sebastião,Jackeline Lunz,Maria Inês Bruno Tavares

doi:10.4236/msa.2016.711055

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), hydrophilic 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), Fourier-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 incorporation, modifying its semi-crystalline structure to a less ordered structure. When nanoparticles and NVP were added, the T1H values increased, for PCL, PCL/S7, PCL/ SiO2 and PCL/TiO2 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/SiO2/NVP system. The amount of NVP included was around 1.5 ± 0.03 mg/cm2. In the in-vitro dissolution test, the PCL/SiO2/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/SiO2 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 occur by diffusion through the matrix pores, thus, these materials are suitable for sustained release of NVP.

Highlights

The combination of organic and inorganic structures within a single material at nanoscopic level is one of the most effective approaches for producing new class of hybrids materials with advanced properties
NVP, an antiretroviral drug, was included within PCL matrix containing three types of nanoparticles: an organoclay layered silicate Viscogel S7® (3% w/w), hydrophilic 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), Fourier-transform infrared spectroscopy (FTIR), low-field nuclear magnetic resonance (NMR), ultraviolet-visible spectroscopy (UV), in-vitro dissolution testing and drug release mechanism kinetics
The disappearance of all NVP crystal peaks indicates the NVP crystallinity was reduced, when the drug is embedded inside the hybrid matrix, indicating an amorphous dispersion of NVP [21] [32]

Summary

Introduction

The combination of organic and inorganic structures within a single material at nanoscopic level is one of the most effective approaches for producing new class of hybrids materials with advanced properties. A wide range of nanoparticles such as: clays, carbon nanotubes, graphites, polyhedral oligomeric silsesquioxane and metal oxides are currently available and used for prepared these systems [1] These new compounds have been increasingly used in biomedical, pharmaceutical and cosmetics applications, presenting many advantages compared with individual polymers or other pharmaceutical excipients, such as: controlled drug release, targeted drug delivery, improved mechanical properties and stability [2] [3]. Compared to other biodegradable polyesters, the in vivo degradation of PCL is considerably long This fact, added to its high permeability to drugs, favors its utilization in the design of long-term implant delivery devices, such as capronor® used to delivery levonorgestrel [6] [7] [8]. Other important fact is that the addition of nanofillers such as hydroxyapatite, clays, titanium oxide, graphite and silica has been reported as not affect the PCL bioactivity [9]

Methods

Results

Conclusion