Aim:The aim of this study was to organize polyelectrolyte complex microparticles (PECMP) of cationic guar gum and xanthan gum. Materials and Methods: The complex formed was loaded with diclofenac sodium (DS) as a model drug. The prepared microparticles were characterized by Fourier transform infrared spectroscopy (FT-IR), differential scanning colorimetry (DSC), scanning electron microscopy (SEM), and evaluated for in vivo in vitro properties. Result: DSC and FT-IR studies were done to measure the formation of PEC and confi rmed the absence of chemical interactions between drug and polymers. By SEM, the surface morphology was studied. Particle size ranged between 294 and 300 μm. The percentage of encapsulation effi ciency of the microparticles was found to be 96.47%. In vitro release studies indicated that the drug release extended beyond 12 h. Kinetic analysis of dissolution data indicated that the drug release was by super case II mechanisms. Compared with DS solution, microparticles show low and prolonged drug release when subjected to in vivo pharmacokinetic evaluation in rabbits. Based on in vitro and in vivo studies, it was concluded that these micro particles provided oral controlled release of DS. Conclusion: The research fi ndings obtained from the studies were found to be satisfactory. Hence, PECMP can be effectively used for preparation of sustained-release formulation.