Composite wafers and films comprising HPMC and sodium alginate (SA) were formulated for nicotine (NIC) replacement therapy via the buccal route. Magnesium aluminium silicate (MAS) was added in different concentration ratios (0.25, 0.5, 0.75) to stabilize NIC and its effect on mechanical properties, internal and surface morphology, physical form, thermal properties, swelling, mucoadhesion, drug content and release behaviour of the formulations was investigated. MAS changed the physico-mechanical properties of the composite formulations causing a decrease in mechanical hardness, collapsed wafer pores, increased roughness of film surface, increase in crystallinity and decreased mucoadhesion of the wafers. However, MAS increased swelling in both films and wafers as well as interaction between NIC and SA, which increased drug-loading capacity. Further, MAS resulted in rapid and slow release of NIC from wafers and films respectively. The results suggest that the ideal formulation for the stabilization of NIC in the composite formulations was MAS 0.25
