Working principle and characteristics of efficient coating machine

An efficient coating machine is a device that forms a film by wrapping a polymer around a tablet core. The efficient coating machine solution is sprayed on the surface of the rolling core by spray, and hot air is introduced to make the solvent on the rolling core evaporate, so that a continuous polymer film is formed on the surface. The formation of fog drops, the movement of fog drops to the core, the impact of fog drops on the surface of the core, spreading, agglomeration and the drying of the film are all important factors affecting the coating. These factors need to be understood and controlled by designers and operators to achieve high-quality coating.

Features of efficient coating machine:

(1) regulating drug release;

(2) improve the stability of the tablet to prevent oxidation and denaturation caused by light or air;

(3) overcome the tablet taste is not good, not easy to swallow the shortcomings;

(4) isolation of easily compatible drugs.

Film formation mechanism and influencing factors:

After the efficient coating machine, the structure of the film on the core is not uniform, and the appearance is different. This heterogeneity is due to the intentional addition of insoluble components, such as color, and the film is not formed continuously during the coating process. Most of the coating process is to dry the polymer solution after it is sprayed onto the solid core, and then accept the next spray. This process needs to be repeated many times until the coating is completed. In order to obtain good coating effect, the formation mechanism of the film should be understood first.

The whole process includes the following important stages:

(1) generation of fog drops;

(2) preparation of coating solution or suspension;

(3) the movement of fog droplets from the spray gun to the flake bed;

(4) impact, wetting, spreading and coalescence of fog droplets on the surface of the chip core or particles;

(5) dry gelling and adhesion to film.