Product Stability and Robustness

      Our products are designed to reduce exposure to a ranges of HPHCs and before biological testing we verify the performance of the products by measuring the smoke chemistry under standardized smoking conditions. We are, however, also verifying that the product performance is maintained with time or usage under a range of real life situations (such as climatic conditions and smoking pattern).

      Product stability

      To verify the product stability and establish a product shelf life, we follow international standards, in particular ICH[1][2][3]and FDA[4]. Multiple batches are stored under predefined conditions, covering the WHO climatic zones defined in ICH guidelines (Q1):

      Different time points are defined, where selected batches will be tested for a range of HPHCs in the aerosol, physical characteristic of the product, sensory property and visual inspection.

      For quantitative data, all values measured are then aggregated together to build a regression model for the time evolution and the confidence limit for every parameter followed in the course of the aging study. The confidence level is then compared to a pre-established spec to define the shelf life of the product.

      UMCL – Upper 95% confidence interval for the regression

      LMCL – Lower 95% confidence interval for the regression

      USL – Upper shelf life specification limit

      LSL – Lower shelf life specification limit

      Product robustness under various climatic conditions

      Our products will be used in different regions therefore we need data to demonstrate that the products performance will be maintained in various climatic conditions.

      To do that, we have a climatic smoking machine enabling testing the products under defined humidity and temperatures. We use the temperature and humidity ranges covering the WHO climatic zones defined in ICH guidelines (Q1), also used for aging studies.


      Product robustness under different puffing regimes

      People smoke differently therefore we need to evaluate product performance under different puffing regimes that we have developed, for example as described by de La Bourdonnaye et al. (2015)[5]

      Using this range of puffing regimes, HPHCs are measured and then plotted vs. nicotine deliveries, to verify that their levels are kept in proportion to nicotine, with the ratio of nicotine to HPHCs either constant or decreasing. This product behavior ensures that the reduced exposure compared to cigarette use will be maintained, regardless of the puffing patterns.

      Two distinct scenario are simulated: the product is stored under different conditions and used under normal (ISO) conditions, or the product is stored and used under different conditions. The focus is then on analysing the aerosol content, deliveries and HPHCs, and the levels are compared to those obtained under standard conditions.