Bioadhesive buccal tablet formulations for delivery of nicotine into the oral cavity were developed. Carbomer (Carbopol(R)974P NF) (CP) and alginic acid sodium salt (NaAlg) were used as bioadhesive polymers in combination with hydroxypropyl methylcellulose (HPMC) at different ratios. Magnesium carbonate was incorporated into the formulations as a pH increasing agent. In vitro release and bioadhesion studies were performed on the developed tablets. In the formulations containing CP:HPMC, the NHT released increased with the increasing HPMC concentration whereas a decrease was observed with increasing HPMC concentration in formulations containing NaAlg:HPMC. The bioadhesive properties of the tablets containing NaAlg:HPMC was not affected by the concentration of the NaAlg (P > 0.05) but increased significantly with the increasing CP concentration (P < 0.05). A decrease in pH of the dissolution medium to acidic values was avoided by incorporation of magnesium hydroxide into the formulations. The developed formulations released NHT for 8 h period, and remained intact except for the formulation containing CP:HPMC at 20:80 ratio. (C) 2004 Elsevier B.V. All rights reserved.