BASICS OF PRESSING POWDER INTO TABLETS

Tableting pressing in pharmaceutical production

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Tableting (pressing) is the process of forming tablets from granular or powdery material under pressure. In modern pharmaceutical production, tableting is carried out on special presses called tablet machines.

Modern capabilities of tablet presses

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Many companies producing pharmaceutical equipment are constantly working on improving the tablet presses and their components used. Recently, the company FETTE (Germany) has improved the rotary tablet press, using a segmented matrix disk instead of traditional matrices. Instead of 47 matrices and 47 screws, only 3 segments are used, which gives clear advantages, such as: high productivity — up to 311 thousand tablets per hour; less time spent to change the product — there is no need to adjust individual matrices; reduced cleaning time, as the number of parts decreases and there are no holes that are difficult to clean; lower tablet ejection force due to reduced friction against the matrix walls; increased service life by 5-6 times due to segments made of high—alloy steel...

Pressing stages for powdered materials

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The whole pressing process is proposed to be divided into three stages: compaction (pre-pressing); formation of a compact body; volumetric compression of the resulting compact body. At the first stage of pressing, under the influence of an external force, the material particles converge and seal due to their displacement relative to each other and filling voids. The forces overcome in this case are insignificant, the seal 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.

Direct pressing of powders in production

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Direct pressing is the process of pressing non—granulated powders. From the technological scheme for obtaining tablets, it can be seen that direct pressing allows you to exclude 3-4 technological operations from the production process. The direct pressing method has a number of advantages, including: reduction of the production cycle time due to the abolition of a number of operations and stages; use of less equipment; reduction of production areas; reduction of energy and labor costs; production of tablets from moisture-, thermolabile materials and incompatible substances. The disadvantages of the direct pressing method include: the possibility of delamination of the tablet mass; changing the dosage when pressing with a small amount of active substances; the need to use high pressure. Some of these disadvantages are minimized...

Excipients for tabletting

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As noted earlier, the creation of effective medicines requires the use of a large number of excipients. Auxiliary substances 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 effect of excipients on the effectiveness and quality of medicines, as well as the requirements for excipients. According to their functional purpose, the excipients are divided into six groups. Fillers (diluents) are added to obtain a certain mass of tablets. With a small dosage of LV (usually 0.01—0.001 g) or when tableting potent, toxic substances, fillers can be used to regulate certain technological indicators (strength, disintegration, etc.). Fillers determine the technological properties of the mass for tableting and the physical and...