The coating machine is an efficient, energy-saving, safe and clean electromechanical machine that can carry out organic film coating, water-soluble film coating, and sustained and controlled release coating on tablets, pills, candies, etc. All-in-one equipment. Coating machines are suitable for pharmaceutical, chemical, food and other industries.
1. It should be noted that general film coating does not have a moisture-proof effect in a strict sense (unless it is used as a sealing layer, which can achieve a moisture-proof effect under special circumstances), because it is strictly moisture-proof. It may cause disintegration or even stop disintegration within a certain period of time, so the so-called moisture-proof film coating mainly refers to the function of delaying the time when the tablet core becomes damp.
2. It is very common to use hydrophobic materials to delay moisture in the tablet core. However, considering economy and safety, the current mainstream coating products use water as the solvent and have the function of delaying moisture in the tablet core. Coating agents with a function of time, such as fully water-proof and moisture-proof coating agents. The main principle is to use special polymer materials that will fully swell in a large amount of good solvent (water), and will swell in a small amount of solvent. The coating agent is fully swollen in a large amount of water in a certain proportion, and a dry continuous film is formed on the surface of the tablet core through operation. During the subsequent storage time, due to changes in external conditions, the film has the opportunity to come into contact with a small amount of water molecules in the air. , at this time, the specific polymer material in the film will expand due to the presence of a small amount of solvent. Of course, other corresponding film performance indicators such as adhesion, elastic modulus, tensile strength, etc. will change to a certain extent, but basically The impact is not big. As the specific polymer material expands one by one, the probability of water molecules coming into contact with the core covered by the film is greatly reduced. At the same time, due to the expansion of the polymer, the pore size for water vapor migration becomes smaller and the migration path becomes smaller. It is longer, thereby increasing the difficulty for water molecules to contact the tablet core, thus protecting the tablet core. However, when almost all specific polymer materials have expanded, this sacrificial stage of delaying moisture is over. Therefore, tablet cores stored for a long time will still be affected by moisture, so film coatings generally only play a role in delaying moisture.