Stability Evaluation Method and Application of Puff-by-Puff Release of Aerosol Constituents in Heated Tobacco Materials and Products.

Puff-by-puff release stability is critical for heated tobacco product (HTP) quality and user experience, yet existing methods lack dynamic puff-by-puff evaluation. Here, we develop a novel stability index (SI) using the "modulus of the sum vector of two evaluation dimensions" algorithm to quantify puff-by-puff release consistency and interpuff variability. In addition, the algorithm has been validated through practical product applications. Compared with traditional methods, SI significantly enhances the differentiation and accuracy of stability evaluation. Under a 10% relative deviation in the release amount measurement, the deviation of the stability index (SI) is maintained at 10.6%, demonstrating precision. The SI is applicable to reconstituted tobacco sheets, HTP sticks, and final products, enabling quantitative stability assessment. As a key screening tool, it streamlines HTPs development by identifying inconsistent formulations early.