The objectives of this contract are to carry out absorption, distribution, metabolism and elimination (ADME) pharmacokinetic studies in animals to characterize the of potential treatment medications. In addition, in vitro metabolism and in vitro absorption studies will also be carried out. The data generated by this contract will be utilized by the NIDA Medications Development Division (MDD) in evaluating the new medications for the treatment of drug addiction. The data/report will be submitted to the FDA in support of INDs (Investigational New Drugs) and NDAs (New Drug Applications).