Effect of ammonium compounds in tobacco on the nicotine absorption in smokers

Several ingredients are added to tobacco during manufacturing of cigarettes to
improve the taste, combustion, or increase the storage life. According to the
tobacco industry ammonium compounds are added for their flavouring properties.
However, recently it has been demonstrated that ammonium compounds might
increase the amount of nicotine absorbed during smoking.

To determine if adding ammonium to tobacco of cigarettes increases nicotine
absorption (amount and speed) in blood of experienced (chronic) smokers.

Experienced smokers smoke two cigarettes from two different brands, that are
commercially available on the Dutch market. Both brands contain the same
amounts of tar and nicotine, but differ in ammonium-content. The study will be
performed according to the cross-over design, in other words, a person smokes
cigarette A in the morning and, after a wash-out period, cigarette B in the
afternoon. Testcigarettes will be smoked via a tube, so volumes will be the
same per puff. In addition, studypersons need to smoke according to a regime:
every 60 sec an inhalation of 55 ml in 2 sec, then a 2 sec breath-hold, after
which smoke can be exhaled. From each cigarette, 6 puffs will be taken, after
which the cigarette will be extinguished. Before, during and after smoking the
test-cigarette, blood (2 times 12 ml and 6 times 3 ml) will be drawn via a
venous catheter (in total 84 ml), and saliva will be collected with a cotton
swab. Study persons are also connected to a real-time bloodpressure and
heartfrequency monitor.

Smoking of a cigarette with a high ammonium-content and a cigarette with a low
ammonium-content.

Volunteers need to visit the Slotervaarthospital once. Smoking the night before
until the study is not allowed. The study comprises 2 times one-and-half hour
investigation. Between the investigations is a 4 hour break, wherein smoking is
not allowed.