title: Nicotine Absorption from Smokeless Tobacco Modified to Adjust pH.
abstract: BACKGROUND
  Nicotine delivery from smokeless tobacco (ST) products leads to addiction and the use of ST causes pathology that is associated with increased initiation of cigarette smoking. The rapid delivery of nicotine from ST seems to be associated with the pH of the aqueous suspension of the products - high pH is associated with high nicotine absorption. However, early studies compared nicotine absorption from different commercial products that not only differed in pH but in flavoring, nicotine content, and in format-pouches and loose tobacco.
  
  
  METHODS
  The present study compared nicotine absorption from a single unflavored referent ST product (pH 7.7) that was flavored with a low level of wintergreen (2 mg/g) and the pH was amended to either high (8.3) or low (5.4) pH with sodium carbonate or citric acid, respectively.
  
  
  RESULTS
  In a within-subject clinical study, the higher pH products delivered more nicotine. No significant differences were seen between perceived product strengths and product experience in all conditions. Heart rate increased by 4 to 6 beats per minute after the high pH flavored and the un-amended product but did not change after the low pH flavored product.
  
  
  CONCLUSIONS
  These results indicate that pH is a primary determinant of buccal nicotine absorption. The role of flavoring and other components of ST products in nicotine absorption remain to be determined.
authors.affiliation: Battelle Memorial Institute, Human Exposure Assessment Laboratory (HEAL), Baltimore, MD.
authors.forename: Wallace B
authors.initials: WB
authors.lastname: Pickworth
authors.affiliation: Battelle Memorial Institute, Human Exposure Assessment Laboratory (HEAL), Baltimore, MD.
authors.forename: Zachary R
authors.initials: ZR
authors.lastname: Rosenberry
authors.affiliation: Notre Dame of Maryland University, School of Pharmacy, Baltimore, MD.
authors.forename: Wyatt
authors.initials: W
authors.lastname: Gold
authors.affiliation: Battelle Memorial Institute, Human Exposure Assessment Laboratory (HEAL), Baltimore, MD.
authors.forename: Bartosz
authors.initials: B
authors.lastname: Koszowski
keywords: CRP2; Moist snuff; Nicotine; Smokeless tobacco; Tobacco