Tablet pressing technology of effervescent tablets

At present, there are two kinds of manufacturing technology of effervescent tablet sugar, i.e pressing after granulating and pressing directly There are two kinds of pressing technology after granulation: wet granulation and dry granulation There are two kinds of direct pressing: powder pressing and crystal pressing However, at present, the wet method is widely used 1 Tablet pressing process after granulation (1) purpose of granulation: ① the fluidity of fine powder of material is poor, which is not easy to flow evenly into the mold hole, thus affecting the accuracy of sugar tablet weight, and the difficulty of tablet forming caused by poor fluidity can be overcome after the granule is made ② There is a certain amount of air in the gap between the particles and powders When the tablet is pressed, part of the air in the powder can not escape in time and is pressed in the sugar tablet; when the pressure is relieved, the air inside the sugar tablet expands and causes cracks; at the same time, the powder tablet pressing has high requirements on the tablet pressing machine, which is easy to damage the machinery The pressure requirement is smaller than that of the powder Because of the uneven surface of the particles, it has the function of "mutual inlay", which can overcome the quality problems such as sugar flakes' loosening and cracking ③ The proportion of different raw materials in the ingredients is quite different In the process of tablet forming, the light and heavy components are layered due to the vibration of the tablet press, and the components and contents of the pressed sugar tablets are inconsistent ④ Solve the quality problems of fine powder, such as easy to stick and flush, and avoid the flying of fine powder when the powder is directly pressed Due to the above reasons, except for some crystalline raw and auxiliary materials which can be directly pressed, the powder raw and auxiliary materials are generally pressed after granulation (2) Wet granulation process: the preparation method of sugar wet granulation of effervescent tablets is as follows: acid and alkali are divided into groups with appropriate raw and auxiliary materials to make soft materials and particles respectively with adhesive, and then they are divided into groups and dried respectively, the whole particle is mixed and then pressed, or the same group is used for granulation The specific operation methods include one-step method, two-step method, three-step method and fusion method The so-called "several steps" are divided into several groups for granulation The "three steps" are to properly divide raw and auxiliary materials and acid-base system into three groups, namely, soft material and wet particles, and then dry them in groups The process: ① preparation and pretreatment of raw and auxiliary materials: before granulation, all raw and auxiliary materials generally need to be crushed, screened or dried, and the fineness of materials generally passes 80-100 mesh sieve ② Material mixing: pour all kinds of materials into the mixer according to the formula requirements and mix evenly ③ Soft material making: put the mixed materials in the tank mixer, mix and add appropriate wetting agent or adhesive The type and amount of binder should be selected according to the nature of the material The temperature and mixing time should be controlled flexibly so that the binder can be evenly distributed and permeated into the dry powder When the material is slightly caked into a block, it becomes soft material, and mixing can be stopped The quality of soft material is generally to hold tightly into a lump, and the fingers can be opened by light pressure and spallation ④ Wet granulation: wet granulation is formed by passing the soft material through a suitable sieve For large-scale production, swing granulator shall be used, and the particles made shall be complete, and the fine powder shall not be too much When sieving, if it is long strip or coarse particles, it is more solid, and the particles containing fine powder are more loose The varieties that are easy to crack should make the granules firmer, and the pressed sugars with large viscosity and difficult disintegration should be made into loose and fine granules Generally, it is screened once, but for the colored varieties or the varieties requiring solid particles, it can be screened many times, such as 1-2 times with 8-10 mesh sieve, and then 12-14 mesh sieve, which can produce better particles According to the properties and varieties of materials, wet particles with different thickness and tightness should be prepared ⑤ Drying: after the wet particles are made, they should be dried immediately If they rotate too long, they are easy to be compressed, deformed or caked The drying temperature and drying process should pay attention to the following aspects: the drying temperature of general materials should be 50-60 ℃; for materials with stable heat, the drying temperature can be appropriately increased to 75-80 ℃, so as to shorten the drying time; for materials with too much crystal water, the drying temperature should not be too high, and the time should not be too long, so as to avoid losing too much crystal water, making the particles brittle or affecting the disintegration or causing tablet forming It is difficult; the temperature should be increased gradually during the drying process, otherwise the surface of the granules will turn yellow, causing spots on the sugar flakes; if there are sugar powder and starch in the granules, the temperature will suddenly melt the sugar, and the starch will gelatinize, causing the granules to be hard, one-sided with spots, and affecting the disintegration of the sugar flakes When sugar and acid coexist, they will bond to a hard lump when they encounter high temperature ⑥ Whole grain: wet grain is called dry grain after drying In the process of drying, some particles adhere to each other to form a block, so it is necessary to screen the whole particles to form particles of uniform size and easy to be pressed The dry particles are screened by the pelletizer (or granulator) to prevent the generation of too much fine powder, and then the screened lubricant is added and stirred evenly If it is necessary to add dry starch as disintegrating agent, it should also be added in the whole granule ⑦ Total mixing: it is the last operation of Zui after dry particle treatment, aiming to make all components in dry particles uniform, and V-shaped mixer is commonly used in production The mixed dry particles are immediately placed in the container, and the samples are pressed to form after passing the inspection Small quantity can also be mixed by hand ⑧ Tablet forming: the process of pressing and forming particles in a tablet press The operation steps of tablet pressing are as follows: adjust the weight of the product to make it consistent; then add materials, press and push the tablet to complete the tablet pressing process ⑨ Picking: reject the unqualified sugar pieces in the formed and pressed pieces ⑩ Packaging: use blister machine or pillow type packaging machine for packaging It is required to be sealed and airtight, with beautiful and complete packaging The most commonly used effervescent tablets made from wet granulation are Zui, which is easy to absorb moisture and appear lobes (3) fluidizing spray drying granulation method: mixing raw and auxiliary materials, mixing with agitation, granulating, drying and so on The operation principle is to use air flow to suspend and fluidize the powder, and then spray the adhesive intermittently, so that the powder first forms the core particles and then gradually agglomerates into particles of uniform size The hot gas passes through the particles, and heat exchange is carried out under dynamic conditions, so that the particles can be dried rapidly During the operation, the materials shall be placed in the conical container first, the bottom of the container is porous plate, 80-100 mesh stainless steel screen shall be laid on the top, and the blower shall be started to make the air enter the granulator from the bottom after being filtered and placed in the heater for heating When the granulator becomes negative pressure, the material moves upward When it reaches the upper part, it moves downward due to the relative drop of pressure, so it looks like boiling up and down Fluidization is uniform for several minutes, then the adhesive liquid is sprayed intermittently, so that the powder gradually condenses into granules As the dry hot air flows from the bottom of the pelletizer to the top, the water is carried away through full contact between the granules, so the utilization rate of heat is very high, and the moist air escapes through the upper pocket filter The dry particles obtained are then processed in the same way as the whole and total mixing Fluidization spray drying granulation method has the advantage: the whole pelletizing operation is completed on one device, simplifying the granulating steps, occupying less space, making granulating operation continuously, short operation time, saving labor and high production efficiency, uniform particle size, good fluidity, adjustable particle size and stable product quality, and closed operation under negative pressure to avoid powder flying Yang, and can achieve full-automatic program control operation The key to fluidizing spray drying granulation is the selection of adhesives and the precise design of the nozzle on the equipment More varieties can be developed by solving the above two key problems The drying degree of the particles can be controlled by moisture content measurement In the production, the dry particles are generally held tightly After the hand is released, the particles cannot be bonded into a ball In addition, the dry particles can be twisted between the index finger and the thumb, which can be crushed without moisture Quality requirements for dry particles: Determination of water content: the water content in particles shall be controlled within a certain range The water content of dry particles depends on the specific varieties, usually with a certain temperature, a certain drying time and the yield of dry particles to grasp the water content; also use a rapid moisture tester to determine the moisture content of particles In addition to the determination of water content, it is also necessary to master the particle tightness, thickness and color (4) Dry granulation: generally, the rolling method is used After the materials are evenly mixed, they are uniformly rolled by a rolling press (double drum rubber mixer) and pressed into thin sheets of required hardness and thickness Then they enter the granulation machine-made particles, add lubricants, and then they are combined by a V-shaped mixer to form tablets However, the method is not widely used because it is easy to produce cracks when laminating and forming 2 The technology of direct tablet pressing refers to the method of tablet pressing directly after the raw and auxiliary materials of powder are screened and evenly mixed The advantages of direct compression of powder: simplifying the operation of compression sugar production, shortening the production cycle, simple production equipment, which is conducive to automation and continuity, without going through the wet and hot process (1) The materials for direct tablet pressing should have a certain thickness, crystal morphology and compressibility (2) In order to press the powder directly, it is necessary to add proper dry adhesive, flux and disintegrator (3) Because there is a lot of air in the powder, it is easy to produce cracks when pressing, and the powder flies a lot The method of increasing pressure is used to overcome the cracks, and the method of airtight is used to overcome the powder flying In addition to direct compression of powder, there is also crystallization direct compression process Some crystalline granular materials have good fluidity and compressibility, and many materials containing crystal water can be directly pressed by adding proper amount of lubricant However, it is easy to burst and punch in the process of tablet pressing, so attention should be paid to inspection At present, there are still some defects in the process of dry direct tablet pressing, which has high requirements for tablet press This kind of large pressure has serious wear on tablet press and die, which will greatly shorten the service life of the equipment At the same time, the powder will fly in the process of tablet pressing, which will not only pollute the production environment, but also harm the health of employees, cause waste of raw and auxiliary materials, and increase the production cost 3 Disintegrating agent adding method (1) common disintegrating agent adding method, generally there are three adding methods as follows: ① internal addition: starch is added into the raw and auxiliary materials, and then mixed to make particles, the disintegration occurs in the inside of the particles, and this method is mostly used for tablet pressing sugar ② External addition: the dry starch is added into the prepared dry granules, and the addition amount is generally 5% of the weight of the dry granules The disintegration of this method occurs between particles, and is often used when the disintegration of tablet sugar occurs ③ Mixing addition: the right amount of starch in the ingredients is mixed with other raw and auxiliary materials to make granules, and the rest is made into dry starch and mixed into dry granules, which has the above two disintegrating effects (2) Generally, there are two ways to add effervescent disintegrator: ① Internal addition: the disintegrating agent is mixed with other materials in the formula and then granulated The ratio of the disintegrating agent to the inside and the surface of the particles is 50-75% and 25-50% of the amount of disintegrating agent, respectively This two-step addition method can make the effervescent tablet sugar immediately disintegrate into the particles before pressing, and the particles further disintegrate into the original powder particles Its disintegration is more complete than external addition ② External addition: that is to say, the disintegrating agent is mixed with particles before tablet pressing, and then tablet forming is carried out