0001). No significant changes in the product pH occurred for either Camel Snus or Marlboro Snus. selleck compound Levels of Constituents per Gram Product Weight When expressed per gram wet weight of product, the mean levels of total nicotine in Camel Snus were lower in the latest large-pouch version of the product, as compared with the original one: 9.4 �� 0.4 mg/g wet weight versus 13 �� 3.2 mg/g wet weight, respectively (Table 1); however, this difference was not statistically significant. The opposite was true for the Marlboro Snus samples: the tobacco of larger pouches released in 2009 contained higher levels of total nicotine than the original ones (p < .0001, Table 1). The levels of unprotonated nicotine per gram product were not different among pouches of various sizes within the same product.

The sum of carcinogenic nitrosamines NNN and NNK in the tobacco of the large Camel Snus pouches was not significantly different than in the tobacco of original and medium pouches. The levels of NNN + NNK in the tobacco of large Marlboro Snus pouches were lower than in the tobacco of original pouches: 1.27 �� 0.7 ��g/g versus 0.50 �� 0.1 ��g/g wet weight, respectively (p < .0001; Table 1). Amounts of Constituents in Single Pouches Comparison of the amounts of analytes contained in a single pouch shows that the large Camel Snus pouches introduced in 2010 contain higher amount of total and unprotonated nicotine than the original small pouches released in 2006 (p < .0001 for both comparisons) and the medium-size pouches introduced in 2008 (p < .0001 for total nicotine and p < .

0002 for unprotonated nicotine; Table 1). In the case of Marlboro Snus, the larger pouches released in 2009 also contained higher amounts of total and unprotonated nicotine than those purchased prior to 2009 (p < .0001 for both comparisons). The amount of NNN + NNK present in large pouches of Camel Snus was 2.3 times higher than in the pouches of medium size (p < .0001) and 3.3 times higher than in the original small pouches (p < .002). Large Marlboro Snus pouches contained lower amounts of NNN + NNK than the earlier version: 0.21 ��g/pouch versus 0.31 ��g/pouch, respectively (Table 1); however, the difference was not statistically significant. Discussion The initial analyses of the new smokeless tobacco products Camel Snus and Marlboro Snus revealed that single pouches of these products contain relatively low amounts of nicotine and the tobacco carcinogens Drug_discovery NNN and NNK, as compared with traditional smokeless products. However, modifications in packaging, flavors, and pouch sizes occurred for both Camel Snus and Marlboro Snus since their first introduction to the market.