Previously, we have reported the preparation and characterization of mucoadhesive pellets of metformin hydrochloride using four high-viscosity polymers including hydroxymethylcellulose (HPMC), HPMC/carbopol, sodium carboxylmethylcellulose (Na-CMC) and sodium alginate (Na-Alg) (Piao et al., Arch Pharm Res 32:391-397, 2009). Here, pharmacokinetic and pharmacodynamic evaluation of these metformin pellets was performed. Metformin pellets were administered orally to normal and streptozotocin-induced diabetic rats at 100 mg/kg dose and the blood concentration of metformin and blood glucose levels were determined. The area under the plasma concentration versus time curve from the Na-Alg-coated metformin pellets in normal rats was $69.93{pm}39.63{mu}g$ h/mL and it was the highest among tested, followed by Na-CMC-coated pellets ($58.38{pm}5.19$), HPMC/carbopol-coated pellets ($52.24{pm}5.29$), HPMC-coated pellets ($42.70{pm}14.29$) and metformin aqueous solution ($33.49{pm}2.04$). The Cmax from the Na-Alg-coated metformin pellets in normal rats was $29.47{pm}10.74{mu}g/mL$ and itwas the highest among tested, followed by Na-CMC-coated pellets ($15.10{pm}2.73$), HPMC/carbopol-coated pellets ($11.38{pm}3.04$), HPMC-coated pellets ($11.29{pm}3.85$) and metformin aqueous solution ($6.92{pm}0.83$). The area under the effect versus time curve of the Na-Alg-coated pellets in diabetic rats was the highest as $670.01{pm}211.20{mu}g$ h/mL, followed by CMC-coated pellets ($542.42{pm}116.93$), HPMC-coated pellets ($539.46{pm}189.91$), HPMC/carbopol-coated pellets ($444.03{pm}90.30$), and metformin aqueous solution ($199.28{pm}31.07$). These data show that the Na-Alg-coated pellets were found to be the best among tested as a new mucoadhesive formulation for metformin hydrochloride prepared by the powder layering technique with a centrifugal fluidizing-granulator.