In vitro study of transdermal nicotine delivery: Influence of rate-controlling membranes and adhesives

The objective of this study was to evaluate the influence of a rate-control ling membrane and adhesive on the in vitro permeation of nicotine. The phys icochemical properties of the adhesive, including adhesion and rheology (vi scosity), were also detected. Higher permeability of nicotine was observed through a hydrophilic membrane than through a hydrophobic membrane. Natural rubber and silicone were used as the adhesive bases, respectively. The sil icone adhesive showed the highest adhesion among all adhesive formulations. To increase the adhesion of natural rubber, a tackifier (polyisoprene) and a secondary tackifier (terpene polymer; Px 1150(R)) were incorporated into the formulations to achieve acceptable adhesion. The nicotine permeation t hrough silicone adhesive and three natural rubber adhesives with the second ary tackifier (2%, 4%, and 6% Px 1150) was close to that from a commerciall y available patch (Habitrol(R)), although the loading amount of nicotine wa s not the same. A longer lag time during the in vitro permeation study of n icotine was required for the adhesives prepared in our laboratory than for the commercially available patch.