The aim of the present work is to investigate the possibility of obtaining a prolonged, relatively constant effective level of Metformin loaded microsphere formulations using Carbopol940 carrier. In the present study carbopol based microspheres bearing metformin were prepared by emulsion–solvent evaporation technique. Three batches of microspheres with different concentration of drug and polymer (FS-1, FS-2 and FS-3) were prepared. The prepared microspheres were studied for drug loading, particle size distribution, in vitro release characteristics, in vivo tissue distribution study and stability studies. The microspheres were found to have diameters within the range of 50 to 110 μm and incorporation efficient of 41 to 69% was obtained. Percent drug release after 8 hours was 97.74%, 96.34% and 93.62% for FS-1, FS-2 and FS-3 respectively. In vitro release profile of all formulations shows slow controlled release up to 8 hrs. The in vivo result of microparticles showed preferential drug targeting to intestine followed by kidneys and spleen. Stability studies showed that maximum drug content and closest in vitro release to initial data was found in the formulation stored at 4ºC. In the present study Metformin loaded microparticles were prepared and targeted to various organs to a satisfactory level and were found to be stable at 4ºC.