Four definitions of tablet press:
1. Tablet press machine, a machine that presses dry granular or powdered materials into tablets through molds.
2. Single punch tablet press, a tablet press that uses a pair of molds for vertical reciprocating motion.
3. Rotary tablet press, a tablet press that uses multiple molds evenly distributed on a rotating turntable to perform vertical reciprocating motion along a certain trajectory.
4. High speed rotary tablet press, with the axis of the mold rotating with the turntable at a linear speed of not less than 60m/min.
Tablet press classification:
The models can be divided into single punch tablet press, basket tablet press, rotary tablet press, sub high speed rotary tablet press, fully automatic high-speed tablet press, and rotary core packing tablet press.
Principle of tablet compression mechanism:
1. Dose control
Various tablets have different dosage requirements, and large dosage adjustments are achieved by selecting punching dies with different punch diameters. After selecting the die size, the small dose adjustment is achieved by adjusting the depth of the punch into the middle mold hole, thereby changing the actual length of the sealed middle mold hole and adjusting the filling volume of the drug in the mold hole. Therefore, there should be a mechanism on the tablet press to adjust the original position of the punch in the mold hole to meet the requirements of dosage adjustment.
2. Control of tablet thickness and compaction degree
The dosage of medication is determined based on the prescription and pharmacopoeia and cannot be changed. For the requirements of storage, transportation, preservation, and disintegration time limits, there are also requirements for a certain dosage of pressure during tablet pressing, which will also affect the actual thickness and appearance of the tablets. Pressure regulation during compression is necessary. This is achieved by adjusting the downward displacement of the punch in the mold hole. Some tablet presses not only have upward and downward movements during the tablet pressing process, but also downward upward movements, which are completed by the relative motion of upward and downward movements. But pressure regulation is mostly achieved through mechanisms that adjust the amount of upward and downward movement to achieve pressure regulation and control.
The working process of the tablet press:
The working process of a tablet press can be divided into the following steps:
1. The punch part of the downward punch (with its working position facing upwards) extends from the lower end of the middle die hole into the middle die hole, sealing the bottom of the middle die hole;
2. Use a feeder to fill the drug into the middle mold hole;
3. The punch part of the upward punch (with its working position facing downwards) falls into the middle mold hole from the upper end and descends a certain stroke, pressing the powder into tablets;
4. Lift the hole upwards. Push the tablet out of the middle mold hole and complete one tablet pressing process;
5. Lower down to the original position and prepare for the next filling.
Structure of tablet press:
The machine that presses granular or powdered materials into tablets by a punch in a mold hole is called a tablet press. The earlier tablet press was composed of a pair of punching dies, which moved up and down to press granular materials into sheets. This machine was called a single punch press, and later developed into an electric basket tablet press. The working principle of these two types of tablet presses is still based on manual compression molds for one-way tablet pressing, which means that during tablet pressing, the downward movement is fixed and only the upward movement is used to apply pressure. This compression method, due to uneven force distribution, results in uneven density inside the tablet and is prone to cracking and other issues.
A rotary multi punch bidirectional tablet press has emerged to address the shortcomings of unidirectional tablet presses. This tablet press uniformly applies pressure while punching up and down, allowing ample time for air in the drug particles to escape the mold holes, improving the uniformity of tablet density and reducing fragmentation. In addition, the rotary tablet press also has the advantages of low machine vibration, low noise, low energy consumption, high efficiency, and accurate tablet weight.
A rotary tablet press is a machine that uses multiple sets of molds evenly distributed on a turntable to perform circular lifting and lowering movements along a certain trajectory, and compresses granular materials into tablets through pressure wheels. A tablet press with a linear speed of ≥ 60m/min that rotates with the turntable is called a high-speed rotary tablet press. This high-speed rotary tablet press has a forced feeding mechanism and is controlled by a PLC. It has functions such as automatic pressure adjustment, controlling tablet weight, removing waste tablets, printing data, and displaying fault shutdown. In addition to controlling the difference in tablet weight within a certain range, it can automatically identify and remove quality problems such as missing corners and loose pieces.
The shape of the tablets pressed by the tablet press was initially mostly flat circular, and later developed into shallow circular arcs and deep circular arcs on both the upper and lower sides, which was for the purpose of coating. With the development of irregular tablet presses, tablets such as elliptical, triangular, elongated, square, diamond, and circular shapes have emerged. In addition, with the continuous development of formulations, special tablets such as double-layer, three-layer, and core packaging need to be made on special tablet presses due to the requirements of compound formulations and timed release formulations.
With the development of market demand, the application scope of tablet press is becoming wider and wider. It is no longer simply limited to pressing Chinese and western medicine tablets, but can also widely press health food, veterinary medicine tablets, chemical tablets: such as camphor pill sanitary ball, washing block, smurf block, art powder, pesticide tablets, food tablets: chicken essence block, Banlangen block, Shenqu tea block, compressed biscuits, etc.
The development history of tablet press:
Tablet presses appeared earlier in Europe and America, with a history of nearly a hundred years. With the improvement of manufacturing and processing technology, automation control technology, and various special requirements of tablet press manufacturers, various special-purpose tablet presses have also emerged one after another. For example, the laboratory uses ZP5 rotary tablet press, dry powder rotary tablet press for dry powder compression, explosion-proof ZPYG51 series rotary tablet press for gunpowder tablets, etc.
Current situation of tablet press:
1. There are numerous specifications and large quantities of tablet presses. It can press circular pieces, engraved pieces, irregular pieces, double-layer pieces, multi-layer pieces, circular pieces, wrapped chips and other types of pieces.
2. Easy to operate. In recent years, tablet press manufacturing companies have begun to attach importance to product quality and mostly adhere to the business philosophy of "winning by quality". Targeting the characteristics of numerous pharmaceutical manufacturers, diverse tablet varieties, and small production scale. The tablet press manufacturing enterprise has developed tablet press products with the characteristics of simple operation, convenient and fast cleaning, especially when changing varieties, the cleaning process is quick and convenient.
3. The tablet press and tablet pressing technology continue to innovate, with high-speed and high-yield production, airtightness, modularity, automation, scalability, and professional testing technology being the main development directions of tablet press technology. Professional tablet presses are mostly based on FETTE KORSCH, MANESTY from the UK, COURTOY from Belgium, STOKES from the US, etc. Its products have a high degree of automation and comply with FDA requirements and 21CFR PART11 requirements.
4. High speed and high output. High speed and high output have been the goals pursued by tablet press manufacturers for many years. Currently, major tablet press manufacturers in the world have machines that can produce up to 1 million tablets per hour. The Xpress700 tablet press produced by Manestroy has a high production capacity of 1 million tablets; The XL800 tablet press produced by Korsch Company has a maximum output of 1.02 million tablets per hour; The maximum output of the Modulus D tablet press produced by Courtoy company is 1.07 million tablets per hour; The 4090i tablet press produced by Fette Company has a maximum output of 1.5 million tablets per hour.
5. The sealing of the tablet pressing process and the isolation of personnel and logistics. The airtightness of the input and output of the tablet press is getting better and better, minimizing cross contamination as much as possible. The particles used for tablet pressing enter the hopper through a sealed material bucket and a sealed conveying system. Effective measures are taken to prevent dust from flying and particle stratification during the tablet pressing process. The pressed tablets enter the packaging process through screening, in tablet detection, metal detection, etc., and the entire process is quite sealed.
6. In place cleaning. WIP (In Place Cleaning) tablet press greatly reduces the user's equipment usage cost. To improve the cleaning function of the tablet press, in addition to fully considering the cleaning of each part in the design, the cleaning function of the tablet press emphasizes disassembly. Only convenient and quick disassembly can ensure the effectiveness of cleaning.
7.Application of 7.21CFRPart11 (Electronic Records and Electronic Signature) on Tablet Press.
On August 20, 1997, the relevant regulations of 21CFR11 Part 6 on electronic records and electronic signatures (ER/ES) issued by the FDA came into effect. For electronic signatures and electronic records, this regulation is mandatory and aims to facilitate the introduction of electronic technology in the processing of pharmaceutical and food products. It can provide applicable and practical guidelines on how to complete tasks that were previously completed in written form through electronic means. Electronic records refer to any combination of digital forms of information expressions created, modified, maintained, archived, retrieved, or distributed through computer systems, such as text, graphics, data, audio, graphics, or others. Electronic signature refers to any one or a series of symbols executed, adopted, or authorized by an individual and compiled from computer data, which have the same legal effect as handwritten signatures of individuals. The application of 21CFR Part 11 technology on tablet presses enables them to have equipment diagnostic record logs, accident record logs, and alarm prompt logs. These electronic records and electronic signatures contain detailed records of various operational data and accident data. Compliant with security access control, requires username and password to enter and operate. All data has been electronically signed, including operator name, date, time, serial number, problem, solution, and operating condition data. All raw data cannot be artificially modified, ensuring the reliability and authenticity of the results. These logs of system and user existence will be automatically stored in the entire 'Trace Review' folder. These security attribute data formats ensure that any changes to the data are carried out under the overall inspection and control of the tablet press.
8.Control technology connected to the entire production line.
Connect a tablet press to a production line. It has start, end, and speed adjustment functions. By using this option function, it is possible to reliably and automatically connect with other equipment on the production line, such as screening, vacuuming, detection, conveying, barrel packaging, etc., to synchronously complete the tablet pressing production task. Meanwhile, different monitoring methods have also been adopted on external devices, providing high safety and reliability performance. The online detector can be used to remove burrs, burrs, and dust from the pressed tablets; The vacuum monitoring function is to use a flow monitor to regularly detect the suction pressure at a designated position in the suction pipe. Continuously comparing the set value with the measured value, if the detector does not detect the suction pressure (no flow) in the suction pipe within 10 seconds, the tablet press will issue a fault alarm prompt and stop running. This function better ensures the reliability of production and can continuously remove dust during the tablet pressing production process. The control technology connected to the entire tablet production line is a new technology for tablet production control and a future development trend.
9. Remote monitoring and diagnosis system for tablet press.
With the rapid development of computer high-tech such as networks, broadband networks, and virtuality, remote monitoring and diagnosis technologies for equipment are also increasingly emerging. Computer controlled tablet presses have been widely used in pharmaceutical factories, making remote monitoring and diagnosis technology applicable in the tablet press industry. The establishment of this system is also to enable the technical support center (the service provider) and the tablet press user (the user) to have a network dialogue through the Internet, so that the service provider can understand the fault of the user's tablet press through the Internet in different places, as well as the working state of the tablet press in executing instructions, and then judge the fault of the tablet press and propose feasible solutions. By establishing a remote monitoring and diagnosis system for tablet presses, real-time troubleshooting can be carried out, greatly improving the after-sales service response capability and speed of tablet press manufacturers, while also enhancing the economic benefits of the enterprise. The remote monitoring and diagnosis system for tablet presses should include personnel allocation, network construction, hardware facilities, software selection, etc., to complete the processes of fault monitoring, analysis, feedback, issuance, and real-time solution services, thereby ensuring the effective operation of the entire system.