TECHNOLOGIES AND EQUIPMENT FOR THE PRODUCTION OF POWDERS

Physicochemical properties of powdered medicine substances

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The shape and size of the particles. Pharmaceutical substances are polydisperse powders, have a complex shape and, as a rule, significant roughness. Powdered medicinal substances (substances) are systems having particles of various shapes and sizes. In many medicinal substances, the particles are anisodiametric (asymmetric, misaligned). They can be elongated (sticks, needles) or lamellar (plates, scales, leaves). A smaller part of powdery substances has isodiametric (symmetrical, equiaxed) particles — these are spherical formations. For example, in JSC "Chemical and Pharmaceutical Combine "AKRIKHIN", studies of samples of substances were carried out, which showed that all the variety of shapes of their crystals in a planar projection can be reduced to several geometric shapes, such as spheres, flat plates (having practically no thickness), volumetric plates, sticks, needles and...

Powder packaging

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Powders are packed in the following materials. Paper capsules. For their manufacture, the following are used: glued paper is a cellulose mass with a glued layer of animal glue. Such paper is mainly used for packaging hygroscopic and non—volatile powders; waxed and paraffin paper is glued paper impregnated with wax or paraffin. Since it does not allow moisture and gases to pass through, it is used for packaging hygroscopic substances (euphyllin), as well as substances that change under the influence of oxygen in the air and carbon dioxide.

Technological properties of powdered medicine substances

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The technological properties of powdered medicinal substances depend on their physico-chemical properties. Fractional (granulometric) composition is the distribution of powder particles by size. The fractional composition has a certain effect on the degree of flowability, therefore, on the rhythmic operation of tablet machines, on the stability of the mass of the tablets obtained, the accuracy of the dosage of LV, on the qualitative characteristics of tablets (appearance, disintegration, strength, etc.). Studies of the fractional composition of pharmaceutical powders to be tableted have shown that most of them contain a fine fraction (less than 20 microns) and therefore have poor flowability. They are poorly dosed by volume on tablet machines, tablets are obtained differently in weight and strength. The fractional composition of powders can be changed...

Mixing powders

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After the grinding and sieving operations, mixing follows, the purpose of which is to obtain a homogeneous mixture of powders. Mixing is usually carried out in parallel with grinding. This leads to the alignment of particle sizes and obtaining a more homogeneous mass. If a component is included in the mixture in a small amount, then additional grinding of its particles is necessary to increase the uniformity of distribution. At the same time, the lower the concentration of it in the mixture, the smaller the particles of this ingredient should be. If a small amount of a poisonous or potent ingredient is added to a large number of substances, then first the latter substance must be thoroughly mixed with one of the ingredients or an...

Bulkiness and compressibility of powders

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When tableting, the most important technological properties of medicinal substances are flowability, compressibility and the force of pushing tablets out of the matrix. Flowability (fluidity) is the ability of a powdery system to pour out of the funnel tank or flow under its own gravity and ensure uniform filling of the matrix channel. The material having poor flowability can stick to the walls of the funnel of the tablet machine through which the material enters the matrix, which disrupts the flow rate and leads to fluctuations in the mass and density of tablets. The flowability (fluidity) of powders is a complex characteristic determined by a number of factors: the dispersion and shape of the particles, the moisture content of the masses, the granulometric composition, as...

Modern methods of drying powders

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Drying is the process of removing moisture from materials using energy to evaporate moisture and from the outlets of the resulting vapors. Among the various technological processes of pharmaceutical production, drying is one of the most significant operations both at the initial and final stages of obtaining pharmaceutical products. The drying process is necessary first of all to remove moisture from the material and bring it to the moisture content set by the regulations. For example, during the production of tablets, the dried granules obtained before the tableting process should have some moisture, called residual. The residual humidity for each tablet preparation is individual and should be optimal, i.e. at which the pressing process proceeds in the best way, the quality of the tablets meets...

Powder production operations and equipment used

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The technological scheme of powder production includes the following operations: grinding, sieving, mixing (in the manufacture of complex powders), dosing (packing) and packaging. The need to perform certain technological operations depends on the prescription, medical purpose and type of starting preparations. If the starting materials (medicinal and auxiliary substances) do not meet the required fractional composition specified in the regulations, they are crushed. Grinding refers to the mechanical process of dividing pieces of solids into smaller ones or turning them into powder, as a result of which the surface of the processed material increases significantly, which significantly accelerates the dissolution of medicinal substances. The goals of grinding are as follows: to provide a rapid therapeutic effect by reducing the particle size and increasing the amount…

Grinding equipment

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The choice of equipment for grinding is determined by the properties of the processed materials and the degree of grinding. A ball mill consists of a rotating closed drum (porcelain or metal), inside which steel or porcelain crushing balls are placed. Mills are of periodic and continuous operation. The mill is hermetically sealed on all sides and has only one loading and unloading tightly closing hatch. After loading the drum with balls and crushed material, the mill is put into rotational motion. The grinding of the material occurs due to impact (the ball nozzle falls on the crushed material), abrasion and partially crushing effects. The advantages of a ball mill are simplicity of design, ease of operation and the absence of powder spraying during operation....

Dosing (filling) with screw and vacuum dosing units

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Dosing (packing) of powders is carried out with the help of special dispensers, mainly screw and vacuum, working on the volumetric principle. Volumetric dispensers are easy to set up, simple to operate, and provide a capacity of up to 300 doses per minute. With a decrease in the dose of the medecines and an increase in the dosage rate, the error increases. Use special dispensers designed for volumetric dosing of bulk medecines in doses from 0.1 to 2 g. Based on the requirements of the GF, deviations in the mass of powders should not exceed certain values. Working principle: the powder is loaded into a hopper. With the help of a regulator, it is fed by a guide agitator through a throttle valve down into...

Vertical granulators and mixer-granulators

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With small batch sizes (up to 800 liters) and/or frequent product changes, drying and cooling of granulates can also be carried out in a vertical granulator. During wet granulation, the powder is loaded into the granulator, then moistened or pollinated by melt. The tangential forces arising during the operation of the Z-shaped rotor blades ensure intensive mixing of the powder and rapid formation of granules with high density when adding binder solutions. The shredder on the side wall of the container prevents the formation of large agglomerates. In this machine, the mixing and wet granulation processes are combined. There is repeated grinding and mixing due to centrifugal forces created by the Z-shaped rotor rotating at the bottom. As a result, uniform fine granules are obtained....