Equipment improvement and technology research of coating machine for sugar coating

Foreword: with the development of tablet film coating technology, the application scope of sugar coating is gradually narrowing, but some varieties are still using this coating technology due to the requirements of patients' taking habits In a period of time, sugar coating has a certain range of applications, can not be completely replaced by film coating Many pharmaceutical factories in China are still using the technology of wrapping sugar coating with water chestnut pot, and using roller coating machine to wrap sugar coating is more automatic, more efficient, more energy-saving, suitable for large-scale production, and can meet the increasingly strict requirements of GMP Compared with water chestnut pot, it has incomparable advantages Drum coating machine is a very suitable equipment for film coating Although the use of drum coating machine for sugar coating has many years of experience both at home and abroad, some pharmaceutical managers and technicians still have doubts about whether it can make sugar coating People's doubts mainly focus on the following aspects: coating efficiency, tablet surface smoothness and smoothness, etc The process of sugar coating by roller coating machine is generally divided into the following stages: feeding, preheating, mixing, single syrup, color paste, polishing and discharging Among them, the three stages of mixing, single syrup and color paste are the circulation of dropping, homogenizing and drying It takes a long time for Zui in the mixing stage, which is the key of sugar coating The color and polish directly affect the one-sided beauty After exploring, we improved the coating machine and explored the coating process 1 The transportation stage of syrup generally accounts for 1 / 5 to 1 / 4 of the whole sugar coating time Improving the transportation flow of syrup can effectively improve the coating efficiency The coating machine requires the use of a mixture of syrup and talcum powder, which is one of the main differences of water chestnut pot icing When coating, if syrup and talcum powder are added respectively, two sets of conveying systems are required due to the large difference between the two materials, which undoubtedly increases the complexity of the equipment, and this method has no practical application Some pharmaceutical factories use the method of adding talcum powder manually, which will cause part of talcum powder to run out of the coating area through the holes on the drum, causing waste, and causing too much burden on the exhaust dust removal system The use of the mixture avoids the above problems In order to increase the rate of mixing, a large flow rate is required The mixture is generally prepared according to the weight ratio of syrup and talcum powder 2:1, and the viscosity is much larger than that of syrup In order to reduce the amount of syrup, the proportion of talcum powder can be increased properly, the single viscosity is also increased, and the fluidity is poor High viscosity and poor fluidity will reduce the speed of mixing and transportation, but reduce the efficiency of coating If we want to maintain a high flow rate, we will put forward higher requirements for the delivery pump and pipeline Peristaltic pump, as a syrup delivery pump, uses a lower viscosity, and must use a hose with a large wall thickness and good resilience, which has a better pressure resistance and resilience self-priming performance It can ensure that the volume of peristaltic pump which can deliver high viscosity liquid under the condition of high flow is generally large, so its use is limited The high price of the pipe with good pressure resistance belongs to consumables, so attention should be paid to the selection 2 Because of the high viscosity of syrup, it is difficult to disperse it into smaller drops and spray it to one side like film coating Therefore, the coating machine generally uses the syrup dropping device to drop the syrup on the tablet bed as evenly as possible, and then enters the homogenization procedure to make the one-sided syrup uniform and consistent The uniformity of syrup dropping directly affects the efficiency of homogenization The more uniform the syrup is, the shorter the homogenization time is In order to make the syrup drop more evenly and shorten the time of homogenization, the dropping width of the device should be the same as the bed width, slightly narrower than the bed width, and the dropping width should account for 70% ~ 90% of the bed width Sufficient liquid supply flow is also the guarantee of consistent flow of each low head syrup 3 After finishing polishing the color paste newspaper, the polishing effect directly affects the one-sided beauty The small holes on the drum of the coating machine make it not have the smooth surface of the water chestnut coating pot, and the movement track of the tablets in the water chestnut coating machine is also more conducive to throwing a more beautiful appearance After groping, we should pay attention to the following points when polishing on the coating machine: the time of adding the polishing wax, the amount of adding, the temperature of the tablet bed, the rotation speed of the roller, and the length of the polishing time The above parameters will be very different due to the different packaged drugs, but they can be solidified in the standard operating procedures through exploration When polishing, the rotating speed of the drum is much higher than that of the coating Using the higher linear speed of the drum to drive the tablets increases the friction speed between the tablets and the friction probability, which is conducive to the ideal one-sided effect In order to improve the rotating speed of the drum, it is necessary to ensure the smooth flow of the bed and avoid the one-sided damage caused by the splashing of the core in the drum The type of agitator in the drum has a direct effect on the high speed of Zui with splashing If the amount of polishing wax is appropriate, more or less will reduce the one-sided brightness The amount of polishing wax is related to the total surface area of the chip core Because the total surface area is large, more polishing wax needs to be added Generally, the chip core is small and the total surface area is large When polishing, pay attention to the one-sided situation The time interval of the ideal surface is short, which can be completed from a few minutes to a dozen minutes generally When the one-sided surface reaches the polishing effect, it is necessary to stop the drum rotation or reduce the drum speed immediately Excessive and insufficient polishing can not meet the ideal surface requirements 4 Coating environment control coating environment refers to the air environment, air humidity, temperature and air volume in the coating drum Temperature and air volume will not be discussed again Air humidity is the most important process parameter for sugar coating The relative humidity of the air entering the drum has an effect on the drying speed and moisture content of the tablets When the air humidity is too high, the efficiency of ten coating can be greatly increased in Jiangdu, and even sugar coating can not be made, which occurs in the high temperature and humidity climate In order to ensure a good coating environment, the sugar coating should be equipped with dehumidification device in the offering The suitable air relative humidity for coating is rh10 ~ 25%, and the air temperature is 50 ~ 80 ℃ Generally, the coating machine adopts condensation dehumidification, and the refrigerant can be used for the air conditioning of pharmaceutical factory, or the coating machine itself is required to be equipped with refrigeration unit After the air passes through the surface cooler of the supply system, the temperature drops to about 14 ~ 15 ℃, at this time, the air humidity is close to 100% After being heated by the heat exchanger, the temperature rises, and the relative humidity decreases, then the ideal environmental humidity can be obtained 5 The coating process control coating machine can realize the automatic control of sugar coating process, which is one of the advantages compared with water chestnut coating machine The process of sugar coating is more complex than that of film coating, and there are more parameters to be controlled Different process parameters need to be set in different stages, such as feeding, preheating, mixing, single syrup, color paste, glazing, cooling and discharging Because there are many unstable factors in sugar coating process, it is required to allow operators to wake up and correct in the automatic control process, so human intervention should be allowed in the process of program control, and human intervention should be continuous coating process The process parameter setting must be explored The process parameter is preset in the control system Before each coating, the operator only needs to call the corresponding control program Appropriate control parameters can reduce the probability of contact between operators and drugs in the coating process, and reduce the number of manual intervention To ensure the stability and consistency of the coating quality of different batches of tablets, and reduce the dependence of forgetting coating quality on operators All of these meet the requirements of GMP, which is one of the main characteristics of chufa pot coating 6 In conclusion, there are many differences between roller coating machine and chufa coating machine in terms of equipment and process requirements for coating flakes Pharmaceutical has explored a reasonable coating process for the coating machine, cooperated with reasonable hardware facilities and control software, which has incomparable business with chufa coating machine, and can completely replace chufa coating machine in packaging sugar coating.