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...
When microencapsulating solid particles by polymerization and polycondensation methods, a polymerization initiator is pre-grafted onto the surface of the encapsulated substance.
The SG type apparatus manufactured by NPO "Pharmedobrazovanie" is used for granulation of powders in a fluidized bed, subsequent drying and dusting. This process is periodic. The body of the device is made of three all-welded sections, sequentially mounted with each other. The principle of operation is as follows: 30 kg of tablet mixture to be granulated is loaded into the food tank in accordance with the recipe. The trolley with the initial components is rolled into the machine and lifted. The air temperature required for fanulation is set, the mixing, fanulation and drying time is set, as well as the cyclicity and frequency of shaking of bag filters. The fan is turned on with the help of a gate that regulates the flow of...
The method of spray drying of the dispersion or emulsion of the encapsulated substance containing polymer and solvent (both organic and aqueous) consists in their dispersion into the flow of a coolant gas. As a result of heat and mass transfer, the solvent is removed from the system and dense particles are formed, the encapsulated substance in which is distributed throughout the volume, and not concentrated in the capsule core. The most widespread groups of substances used for encapsulation by spray drying are carbohydrates, including modified and hydrolyzed starches, cellulose derivatives, gums and cyclodextrins; proteins, including whey proteins, casein and gelatin; biopolymers. The type of shell material used affects not only the encapsulation efficiency, but also the morphology of the product particles.
During microencapsulation by extrusion, a thin viscous film of film-forming material is formed on the surface with small diameter holes, through which the encapsulated substance is pressed. The shell formed in this way is further stabilized by cooling or polymerization of its constituent monomers. For microencapsulation by extrusion, forming devices are also used, which are two coaxially arranged tubes of different diameters (a "pipe in a pipe" device). The encapsulated material is fed into the inner hole of the tube under pressure, and the shell material is fed into the inter—tube space.
Crosslinking of polymer chains is carried out by introducing special substances into the system, which, as a result of ion exchange, form bonds between two neighboring chains. In this case, the process takes place at the interface of the phases. It is possible to use oil-in-water systems containing a hydrophilic polymer and, for example, lower aldehydes as crosslinking agents. In this case, the interaction of the polymer with the aldehyde occurs in the aqueous phase, resulting in the formation of a new phase deposited on oil droplets, since the higher aldehydes dissolve in the non-polar phase.
In modern pharmaceutical production, the following methods of applying film coatings are used.Coating in drums; coating in a fluidized bed (spraying from above, spraying from below, coating tangentially); technology of jet fluidization. Coating in drums has already been discussed in the section "Methods and equipment for coating".The technological parameters of the film coating process are: temperature, quantity and humidity of incoming and outgoing air, spray rate and pressure from the nozzle, layer temperature. At the same time, the technological parameters can be adjustable (temperature and amount of incoming air), unregulated (humidity at the inlet) and fixed (spray rate and duration of the process. DIOSNA has developed a vertical centrifugal coater VCC (from the English coater — coating plant). Unlike conventional drum-type coating systems, the VCC...
After the tableting process, the finished tablet most often needs to be coated. In the modern pharmaceutical industry, the importance of tablet coating is increasing.
Equipment for assembling, cutting and laying adhesive plaster (Leucoplastrum), or elastic external adhesive plaster (Emplastrum adhaesivum elasticum externum). It is possible that the assembly, cutting and capping of a small and medium-sized adhesive plaster is carried out on an automated EURO type in the Italian company EURVSICMA. Depending on the material and size of the patch, the average productivity of the machine is 2000 patches per minute. Let's consider the operation of the machine on the example of the production of adhesive plasters "Uniplast bactericidal" and "Bactericidal Veropharm", which, although they differ in the formulations of adhesive compositions and used antiseptics, have the same production technology.
Microspheres (pellets) are a new type of solid dosage form. Recently, in the pharmaceutical industry, drug manufacturers have been producing microspheres, or pellets (from the English pellet — ball, pellet, pellet), as the final or intermediate type of dosage form for the production of finished dosage forms. Microspheres are increasingly being used in the production of finished medicines, as they have a number of significant and undeniable advantages. Pellets can be tableted with the addition of suitable excipients, they can be the contents of capsules, as well as be part of suspensions. Microspheres (pellets) are agglomerates of fine powders or granules, which, in turn, may consist of medicinal and auxiliary substances. Microspheres are small, spherical or hemispherical solid particles with a diameter of 0.5 to...