The present invention provides a foamed and/or aerated substrate for transmucosal and/or transdermal applications. The foamed and/or aerated substrate may be in the form of a film, sheet, strip or wafer. The foamed and/or aerated substrate is suitable for use in applications such as, for example, adhesive denture liners, tooth whitening, and smoking control/cessation. The foamed and/or aerated substrate is polymeric in nature and comprises one or more polymers and one or more foaming agents. Additionally, the foamed and/or aerated substrate may include, but not limited to, one or more plasticizers, hydrophobic barrier agents, tooth whitening agents, antioxidants, preservatives, super-disintegrants or absorbents, flavorants, deodorants, breath freshening agents, colorants, surfactants, film modifiers, cross-linking agents, antimicrobial agents, control release agents, other therapeutic agents, or any combinations thereof.