Principal Investigator: Yunan Tang (CTP Contact: Prabha Kc)
Funding Mechanism: FDA Internal
ID Number: E07716.01
Award Date: 9/11/2019
Institution: National Center for Toxicological Research (NCTR)
Nicotine is a naturally occurring alkaloid that is found in many nightshade plants, with most human exposure occurring through exposure to tobacco. The CTP-NCTR InhaleCore Group has recently completed studies evaluating nicotine pharmacokinetics (PK) profiles in rats following a single dose administration by inhalation, oral gavage, and intravenous injection (E07607.01). In these studies, the dose formulations for inhalation exposure consisted of nicotine in propylene glycol and water. PK samples were collected at 10 different timepoints ranging from 3 minutes to 48 hours post-dose exposure. Early PK timepoints (< 15 minutes post-dose) were collected using venous blood via the tail vein (i.e., peripheral source), whereas later PK timepoints were collected using arterial blood via terminal cardiac puncture (i.e., systemic source). For the venous blood to reflect the PK sample of the arterial blood, a minimum of 15 minutes is needed post-dose exposure. In this study, early PK timepoints will be collected using arterial blood via cardiac puncture to obtain a more accurate assessment of nicotine levels post-dose exposure. Two timepoints (5 and 10 minutes) to replace the timepoints from the previous study data collection via the tail vein and one additional 30-minute timepoint will be included, to provide an overlapping datapoint with the previous study data collection via cardiac puncture. Results will provide useful information to characterize nicotine kinetics across different routes of exposure, which is critical for the development of the physiologically-based PK model for nicotine and its metabolites (cotinine and 3-hydroxycotinine) in rodents across different routes of exposure. This scientific data may be used to identify and assess potential public health concerns related to nicotine inhalation exposure and may inform potential nicotine product standards.