Nicotine substitution or maintenance has been shown to be an effective aid for ceasing smoking. The overall goal of this program is to develop a nicotine transdermal delivery system as an aid to cessation of smoking based on BIOTEK, Inc.'s DermaPatch concept and systems for preparing sustained release preparations of liquid materials. This system, called NicoPatch, will be designed to deliver nicotine for at least 24 hours at a dose sufficient to maintain blood level of about 20 ng/ml. In preliminary studies sustained release matrixes were produced and tested. A prototype vehicle has been shown to deliver nicotine transdermally in vitro. The objective of the Phase I studies is to demonstrate the feasibility of this system. Specifically a sustained release nicotine DermaPatch matrix will be developed and characterized by in vitro drug release rates. Utilizing nude mouse skin in vitro transdermal diffusion of NicoPatch formulations will be evaluated. The rate of delivery of nicotine and the blood levels achieved will be estimated by in vivo studies in guinea pigs and rabbits. During Phase II further in vitro and in vivo testing will be required to optimize the formulation. Toxicology studies will be conducted and an IND application filed. Based on these studies industrial support will be sought for commercializing the system.