Problems and Countermeasures of Film Coating Technology
2019-09-09 16:04:49
A relatively stable polymer film is sprayed on the surface of the core by spraying to form a plastic film layer of several micrometers thick to achieve a certain desired effect. This process is called film coating. The application of film coating technology is a demand and development trend of the pharmaceutical industry. Some people think that the film coated tablets are not as good as the sugar-coated tablets, and are not as bright as the sugar-coated tablets. In fact, the film coating has many advantages compared with the traditional sugar coating technology, such as the coating is short in time, more moisture-proof and protected from light. The drug is more stable and so on.
It is very important that the film-coated garments have to change the concept of sugar coatings in the past. For a long time, some pharmaceutical companies have simply regarded the film coating technology as an independent link in the production of tablets. The film-coated clothes are just plain coatings like sugar coatings. In fact, it is not that simple. As a new technology, the requirements of the film-coated garment on the core are much stricter than those of the sugar-coated garment. The hardness of the film is relatively high, and it is a combination of various processes and a series of techniques in the production process. Adjustments and interoperability of indicators and requirements are required. Therefore, the introduction and application of film coating technology must be treated in a scientific and realistic manner. Only in this way can the packaged film achieve the desired effect.
Good core quality has a decisive influence on the film coating. Sometimes the mechanical quality of the core is too poor, and film coating is impossible at all. Even if it is barely carried out, the quality of the film is difficult to guarantee. Among all the factors affecting the mechanical properties of the core, the hardness and friability of the sheet are important, and the friability is more prominent than the hardness. In general, the hardness of a medium tablet suitable for a film coating should be 5 kg/cm3, and the hardness of a western tablet should be about 4 kg/cm3. How to check it? The simple method of zui is the hardness tester; or a piece of plain is thrown up 2 meters vertically to make it free to fall, and the hardness is qualified if it is not broken twice or more. A simple way to check the friability is to use a finger to force the edge of the blade or the surface of the sheet. It is better to have no powder falling off. Another method is to place 30 pieces of plain tablets in a 250ml glass and shake them twice. In the minute or so, it is preferable that the surface of the sheet and the edge of the sheet are not worn. For the hygroscopic film, the hardness requirement is higher.
When coating with a film coating technology, whether it is coated with a high-efficiency coating machine, a fluidized bed coating machine, or a sugar-coated pan, the following principles should be followed: First, the hardness of the core should be hard enough, otherwise When the coating starts, the core of the tablet and the wall of the pot repeatedly rub, and there will be pine flakes and pockmarks; the second is that the temperature of the bed should be kept constant; the third is the amount of solvent evaporation in the equipment and the amount of solvent brought in during the spraying process. To maintain balance, solvent evaporation and spray rate are in dynamic equilibrium.
The key to smooth and delicate one-sidedness is to grasp the relationship between pot temperature, spray volume and speed during the whole process, which is the top priority in the film coating operation. During operation, the degree of atomization of the coating liquid directly affects the appearance quality of the coating film formed by the coating, and the atomization effect of the spray liquid is directly determined by the atomization pressure and the atomization system. At the beginning of the spray, the principle of mastering the speed of spraying and the temperature of blowing hot air is to make the sheet surface slightly moist, and to prevent the sheet surface from sticking, and the temperature should not be too low. If the temperature is too high, the drying is too fast, the film formation is easy to be rough, and the color of the film is uneven; if the temperature is too low, or the spray speed is too fast, the humidity in the pan is too high, and the adhesion of the film will soon appear. . The relationship between the rotation speed of the pan and the coating operation is: the rotation speed is low, the adhesion of the film is strong; the rotation speed is high, the adhesion of the film is poor, and the film is easily peeled off. During the coating process, if the temperature is too low, the spray volume is too large, and the film flows, the sticking phenomenon may occur. At this time, the rotation speed can be increased to improve, and if necessary, the temperature, the spray amount, and the spray range can be appropriately adjusted to overcome.
In the case of using the quality of the coated powder, the problems often occurring in the coating operation and the solutions are as follows:
1. Adhesive sheet: It is mainly because the spray volume is too fast, which violates the principle of solvent evaporation balance and causes the sheets to stick to each other. In this case, the spray volume of the coating liquid should be appropriately reduced, the hot air temperature should be increased, and the rotation speed of the pot should be accelerated.
2, the appearance of "orange peel" film: mainly due to improper drying, the spray pressure of the coating liquid is low, so that the sprayed droplets are unevenly heated and the film is corrugated. In this case, the evaporation rate should be controlled immediately to increase the spray pressure.
3, "bridge": refers to the film on the lettering film caused by the logo is blurred. The solution is to slow down the spray speed of the coating and reduce the drying temperature, and at the same time, control the hot air temperature.
4, the appearance of stains: This situation is caused by uneven mixing with the coating liquid or the fineness of the solid traits. The solution is to mix well with the coating liquid.
5. Cracks, cracks, flaking or edge wear of the tablets on the surface or edge of the tablet: if the solid content of the coating liquid is improperly selected, the speed of the coating machine is too fast, and the spray volume is too small, the appropriate coating liquid should be selected. Solid content, appropriate adjustment of the speed and the amount of spray; if the hardness of the core is too bad, the formulation and process of the core should be improved.
6, the performance of the film appears "blooming": This situation is caused by the high humidity of the hot air, the spray path is too long, the atomization effect is poor. At this time, the temperature should be appropriately lowered, the spray range should be shortened, and the atomization effect should be improved.
7. There is color difference between the tablets: this situation is caused by the uneven fan-out of the spray or the excessive solid content of the coating liquid or the slow rotation speed of the coating machine. At this time, the angle of the spray gun should be adjusted, the solid content of the coating liquid should be lowered, and the rotation speed of the coating machine should be appropriately increased.
8. There are pinholes on the surface of the film: This is caused by the excessive air entrapped in the preparation of the coating solution. Therefore, avoid excessive air entrapment during dosing.
Ginseng Leaf Extract;Ginseng Berry Extract;Plant sterol ester;Hyaluronic Acid etc. can be widely used in Cosmetic industrial for skin care,
As a very professional supplier of cosmetic in China, we always give our customers best support with good quality in every field, we instant we will be your reliable partner and business support.
Gingseng Leaf Extract UV80% Re 17% HPLC
Ginseng Berry Extract UV80% Re 20% HPLC
Plant sterol ester 70% from pine tree and soybean source
Sodium hyaluronate
Cosmetic
Cosmetic Raw Material,Leaf Extract,Panax Ginseng Berry Extract,Hyaluronic Acid
Excellent Health Products Co.,Ltd. , http://www.sino-excellent.com