La forma y tamaño de las partículas. Las sustancias farmacéuticas son polvos polidispersos, tienen una forma compleja y, por regla general, una rugosidad significativa. Las sustancias medicinales en polvo (sustancias) son sistemas que tienen partículas de diversas formas y tamaños. En muchas sustancias medicinales, las partículas son anisodiamétricas (asimétricas, desalineadas). Pueden ser alargadas (palos, agujas) o laminares (placas, escamas, hojas). Una parte más pequeña de las sustancias en polvo tiene partículas isodiamétricas (simétricas, equiaxiales): son formaciones esféricas. Por ejemplo, en JSC "Chemical and Pharmaceutical Combine" AKRIKHIN se llevaron a cabo estudios de muestras de sustancias que demostraron que toda la variedad de formas de sus cristales en una proyección plana se puede reducir a varias formas geométricas, como esferas, placas planas (prácticamente sin espesor), placas...
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.
Las propiedades tecnológicas de las sustancias medicinales en polvo dependen de sus propiedades fisicoquímicas. La composición fraccional (granulométrica) es la distribución de partículas de polvo por tamaño. La composición fraccional tiene un cierto efecto sobre el grado de fluidez, por lo tanto, sobre el funcionamiento rítmico de las máquinas de tabletas, sobre la estabilidad de la masa de las tabletas obtenidas, la precisión de la dosificación de LV, sobre las características cualitativas de las tabletas (apariencia, desintegración, resistencia, etc.). Los estudios de la composición fraccionada de polvos farmacéuticos a comprimir han demostrado que la mayoría de ellos contienen una fracción fina (menos de 20 micras) y, por lo tanto, tienen poca fluidez. Están mal dosificados por volumen en las máquinas de tabletas, las tabletas se...
Después de las operaciones de molienda y tamizado, sigue la mezcla, cuyo propósito es obtener una mezcla homogénea de polvos. La mezcla generalmente se lleva a cabo en paralelo con la molienda. Esto conduce a la alineación de los tamaños de partícula y a la obtención de una masa más homogénea. Si se incluye un componente en la mezcla en una pequeña cantidad, entonces es necesaria una molienda adicional de sus partículas para aumentar la uniformidad de la distribución. Al mismo tiempo, cuanto menor sea su concentración en la mezcla, más pequeñas deben ser las partículas de este ingrediente. Si se agrega una pequeña cantidad de un ingrediente venenoso o potente a una gran cantidad de sustancias, primero se debe mezclar bien esta última sustancia...
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...
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...
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…
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 (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...
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....