As noted earlier, the creation of effective drugs requires the use of a large number of excipients. Excipients in tablet production are intended to give the tablet mass the necessary technological properties that ensure: dosing accuracy, mechanical strength, disintegration, stability during storage. The influence of excipients on the effectiveness and quality of drugs, as well as the requirements for excipients. According to their functional purpose, excipients are divided into six groups. Fillers (diluents) are added to obtain a certain mass of tablets. With a small dosage of the drug (usually 0.01-0.001 g) or when tabletting potent, toxic substances, fillers can be used to regulate certain technological parameters (strength, disintegration, etc.). Fillers determine the technological properties of the tabletting mass and the physicomechanical properties of the finished tablets. The cheapest and most affordable excipients available are starch, glucose and sugar.
The whole process of pressing is proposed to be divided into three stages: compaction (prepressing); compact body formation; volumetric compression of the resulting compact body. At the first stage of pressing under the influence of an external force, the particles approach and densify the material particles due to their displacement relative to each other and the filling of voids. The efforts overcome in this case are negligible, the compaction becomes noticeable even at low pressures. The applied energy is mainly spent on overcoming internal (between particles) and external (between particles and matrix machines) friction.
Many companies manufacturing pharmaceutical equipment are constantly working on improving the used tablet presses and their components. Recently, the company FETTE (Germany) has improved the rotary tablet press, using a segmented matrix disk instead of traditional dies. Instead of 47 dies and 47 screws, only 3 segments are used, which gives obvious advantages, such as: high productivity - up to 311 thousand tablets per hour; less time spent on product changes - no need to adjust individual matrices; reduced cleaning time, as the number of parts is reduced and there are no holes that are difficult to clean; lower tablet ejection force due to reduced friction against the matrix walls; 5-6 times longer service life due to segments made of high alloy steel and lower friction forces; reduction of product losses up to 50% due to the absence of sharp edges and the presence of a smooth ...
Tableting (pressing) is the process of forming tablets from granular or powder material under pressure. In modern pharmaceutical production, tabletting is carried out on special presses called tablet machines.
Direct compression is the process of pressing granular powders. From the technological scheme for producing tablets, it can be seen that direct pressing eliminates 3-4 technological operations from the production process. The direct pressing method has several advantages, these include: reducing the time of the production cycle by eliminating a number of operations and stages; use less equipment; reduction of floor space; reduction of energy and labor costs; obtaining tablets from moisture-, thermolabile materials and incompatible substances. The disadvantages of the direct compression method include: the possibility of delamination of the tablet mass; dosage changes during pressing with a small amount of active substances; the need to use high pressure. Some of these drawbacks are minimized when tableted by forcing the compressed substances into the die. However, despite a number of advantages, direct compression is slowly being introduced into production. This is because for the productive work of tablet machines ...
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