Development of a novel intraarticular injection of diclofenac for the treatment of arthritis: a preclinical study in the rabbit model

Purpose: To develop a novel intraarticular injection of diclofenac for the treatment of arthritis. Method: Diclofenac loaded nanoparticles were prepared by a nanoprecipitation technique using Eudragit L 100 as the polymer and polyvinyl alcohol as the surfactant. The nanoparticles were evaluated for particle size, zeta potential, scanning electron microscopy, drug release, encapsulation efficiency, and loading efficiency studies. The optimized nanoparticulate formulation was developed for intra articular injection. Intraarticulate injection was evaluated for pH, appearance, viscosity, osmolarity and syringability studies. The optimized injection formulation was tested in an arthritic model consisting of 25 rabbits. Result: Nanoprecipitation method was found to be suitable for diclofenac nanoparticles. The shape of the prepared nanoparticles was found to be spherical and devoid of any cracks and crevices. The average particle size of a diclofenac nanoparticle was found to range from 87 +/- 0.47 to 103 +/- 0.26 nm. The zeta potential of the prepared nanoparticles was found to be in the range of 0.598 +/- 0.34 to 0.826 +/- 0.25 mV. The encapsulation efficiency was found to be between 73.45% to 99.03%, while the drug loading was observed between 10.34 to 35.32%. The percentage drug release at 12 hours was found to range from 73.45% to 99.03%. Conclusion: The developed intraarticular injection was found to be within the physically and chemically accepted limits. Animals treated with the intra articular injection of diclofenac showed a significant reduction in swelling as compares to the other groups.