A review concerning peculiarities of the application of mathematical models describing mass-transfer processes in film coating technology is presented. A formula to calculate the coating film thickness for a biconvex tablet is given. A model based on the Fokker–Planck equation is described. It determines the law of distribution of coated tablets by weight and allows equations for calculating the average weight and dispersion of a coated tablet to be obtained. Therefore, the uniformity of the distribution of the coating material over the tablets can be evaluated. The mass-transfer equations shown in the review make it possible to calculate characteristics such as the product moisture content and the humidity in a coater drum. © 2022, Springer Science+Business Media, LLC, part of Springer Nature.