Stability of varenicline concentration in saliva over twenty-one days at three storage temperatures.

Assessing saliva varenicline concentrations can be useful for the evaluation of adherence in smoking cessation trials. Saliva is a non-invasive matrix suitable for mail-in specimen collection. This is the first investigation of stability of varenicline in saliva. Varenicline, nicotine, cotinine, 3'-hydroxycotinine and 3HC/COT were stable in saliva for up to 21 days at room temperature (~25°C), 4°C and -80°C, supporting the use of a mail-in approach for saliva specimen in smoking cessation trials.