Participants ( 18-55 years , 10 cigarettes/day , smoking within 1 hr of waking , expired carbon monoxide > 10 ppm on screening ) orally inhaled 2 single doses of nicotine ( 2 of 3 dose levels [ 0.22 , 0.45 , and 0.67 mg ] ) ( Part A ) and repeated hourly doses of 0.67 mg nicotine for 12 hr ( Part C ) , via the novel device .