Formulation, Optimization and Characterisation of Chitosan Based Diclofenac Sodium Loaded Microspheres for Intra-Articular Treatment of Rheumatoid Arthritis

Abstract

The use of polymeric carriers in formulations of therapeutic drug delivery systems has gained widespread application, due to their advantage of being biodegradable and biocompatible. Among the microparticulate systems, microspheres have a special importance since it is possible to target drugs and provide controlled release. Diclofenac sodium (DS), is a potent drug in the NSAID group having non-steroidal, anti-inflammatory properties, and is widely used in the treatment of rheumatoid arthritis, osteoarthritis and ankylosing spondylitis. The aim of present investigation was to develop Diclofenac sodium loaded chitosan natural biodegradable polymer microsphere for intraarticular administration for treatment of rheumatoid arthritis. Various formulations were prepared by varying the ratio of chitosan, span-80, amount of glutaraldehyde, stirring time and rotational speed. The SEM study showed that microspheres have smooth surfaces. Microspheres were characterised by Fourier transform infrared (FTIR) spectroscopy and differential scanning calorimetry (DSC) to confirm the absence of chemical interactions between drug and polymer and to know the formation of microspheres structure. The microspheres were evaluated for particle size, encapsulation efficiency, drug loading capacity, in vitro drug release studies. Particle size, was found to be dependent on rotational speed and concentration of emulsifier and was in the range of 17.1-36.4 μm with percentage entrapment efficiency in range of 70-74 %. In-vitro drug release studies of microspheres revealed that the microspheres were able to control the release of diclofenac over a period of 96 h. The result concluded that diclofenac sodium loaded chitosan microspheres could be used as potential drug delivery system for treatment of rheumatoid arthritis.