Formulation and in vitro characterization of Eudragit® L100 and Eudragit® L100-PLGA nanoparticles containing diclofenac sodium

Abstract

The aim of this study was to formulate and characterize Eudragit® L100 and Eudragit® L100-poly(lactic-co-glycolic acid) (PLGA) nanoparticles containing diclofenac sodium. Diclofenac generates severe adverse effects with risks of toxicity. Thus, nanoparticles were prepared to reduce these drawbacks in the present study. These nanoparticles were evaluated for surface morphology, particle size and size distribution, percentage drug entrapment, and in vitro drug release in pH 6.8. The prepared nanoparticles were almost spherical in shape, as determined by atomic force microscopy. The nanoparticles with varied size (241-274 nm) and 25.8-62% of entrapment efficiency were obtained. The nanoparticles formulations produced the release profiles with an initial burst effect in which diclofenac sodium release ranged between 38% and 47% within 4 h. The extent of drug release from Eudragit® L100 nanoparticles was up to 92% at 12 h. However, Eudragit®/PLGA nanoparticles showed an initial burst release followed by a slower sustained release. The cumulative release at 72 h was 56%, 69%, and 81% for Eudragit®/PLGA (20:80), Eudragit®/PLGA (30:70) and Eudragit®/PLGA (50:50) nanoparticles, respectively. The release profiles and encapsulation efficiencies depended on the amount of Eudragit in the blend. These data demonstrated the efficacy of these nanoparticles in sustaining the diclofenac sodium release profile.

Fig. 1

AFM images of drug-loaded Eud/PLGA nanoparticles a 20:80, b 30:70, c 50:50, and d Eudragit^®L100 stabilized using polyvinyl alcohol showing the spherical shape of particles

Fig. 2

Particle sizes distribution of Eudragit^®L100 nanoparticles and Eudragit^®/PLGA nanoparticles by Malvern Zetasizer. The mean particles size of the nanoparticles (a 20:80, b 30:70, c 50:50, d Eudragit^®L100) obtained was 241, 247.4, 263, and 274 nm with a polydispersity index of 0.18, 0.13, 0.12, and 0.19, respectively (mean ± SD, n = 3, p < 0.05)

Fig. 3

In vitro release profile of diclofenac sodium in phosphate buffer of pH 6.8 at 37°C from Eudragit^®L100 nanoparticles and Eudragit^®/PLGA nanoparticles (mean ± SD, n = 6, p < 0.05)