A variety of layers with different characteristics can be applied. Pellets obtained by this technology have many positive characteristics such as spherical shape, good flowability, dosability, compact structure, low hygroscopicity, high bulk weight, dense and homogeneous surface layer, narrow particle size distribution, high resistance. External to abrasion, the ability to incorporate a large number of species of multilayer bioactive substances and optimal initial pellet shape for subsequent coating. With the rotor method, it is possible to apply the film in very thick layers. Pellets containing large amounts of bioactive substances (when necessary) can be produced with this technology. In layer-by-layer pelletizing, the biologically active substance can be: sprayed onto the initial nuclei as a solution with a concentration of up to 50%; sprayed as a suspension; dosed in powder form in combination with a solvent and binder feed.

In this case, the mass gain during layer-by-layer pelletizing in the rotor can be up to 10-fold of the initial mass. The layering of drug on microspheres is also carried out in centrifugal granulators, which can be used to obtain multi-element products with conventional or modified drug release. Using such systems, the primary granules can be prepared, drug substance layered and coated in the same, equipment to produce spherical multilayer granules with the desired drug substance release. In addition to the methods described above, which are the most common, other methods of producing microspheres such as globulation, solidification and compression are used to a limited extent in the pharmaceutical industry. Globulation consists of two related processes: spray drying and solidification. Spray drying is a process in which a suspension or solution of a drug substance without excipients is atomized in a stream of hot air to produce dry spherical particles.