The SG type apparatus manufactured by NPO Pharmmedoborudovanie is used for granulation of powders in a fluidized bed, subsequent drying and dusting. This process is periodic. The casing of the apparatus is made of three all-welded sections sequentially mounted with each other. The principle of operation is as follows: 30 kg of the tablet mixture to be granulated are loaded into the food tank in accordance with the recipe. The cart with the initial components rolls into the apparatus and rises. The air temperature required for fanling is set, the mixing, fanling and drying times are set, as well as the cyclicality and frequency of shaking of the bag filters. The fan is turned on using a gate, which regulates the flow of fluidizing air, sets the required degree of fluidization of the treated mass. At predetermined intervals, the shutter in front of the fan closes, the drive that sweeps the bag filters turns on, and at certain intervals, the nozzle and the metering pump supplying the fanating fluid turn on automatically ...
Dry granulation is a method in which a powdery material (a mixture of drugs and excipients) is compacted to produce granulate. Dry granulation is used in cases where wet granulation affects the stability and / or physicochemical characteristics of the drug substance, as well as when the drug and excipients are poorly compressed after the wet granulation process. If medicinal substances undergo physical changes during drying (melting, softening, discoloration) or enter into chemical reactions, they are briquetted, i.e. briquettes are pressed from powder on special briquetting presses with large dies (25x25 mm) under high pressure.
There are some requirements for granulating liquid, one of which is that the granulating liquid should not dissolve the active substance. As the granulating liquid, water, an aqueous solution of ethanol, acetone and methylene chloride can be used. As a binding agent for wet granulation in modern pharmaceutical production, a wide range of substances is used, for example: starch (5-15% g / g), starch derivatives, cellulose derivatives that improve the ductility of granules, as well as gelatin (1-3% g / g) and PVP (3-10% g / g). The most common and effective wet granulation binder in the modern pharmaceutical industry is a synthetic polymer such as Collidone (PVP), various brands of which (Collidon 25, 30 and 90F) are widely available on the market.
When grinding solid materials on equipment considered earlier, a homogeneous product is practically impossible, therefore, to separate larger particles, it is necessary to carry out an operation such as sieving. Screening is an integral part of grinding to obtain a mixture with a specific particle size distribution. Sifting eliminates soft conglomerates of powders by rubbing them through perforated plates or sieves with a defined hole size. Screening, or screening, is the process of separating a mixture of grains of various sizes using sieves into two (or more) groups. The grain size passing through the sieve cells is characterized by a number. There are 16 different screens, which correspond to 7 degrees of grinding.
Granulate is obtained in the process of granulation of wet mass on special machines — granulators. The principle of operation of granulators is that the material is wiped with blades, spring rolls or other devices through a perforated cylinder or mesh. To ensure the wiping process, the machine should work in optimal mode without overload so that the wet mass freely passes through the holes of the cylinder or mesh. If the mass is sufficiently moistened and moderately plastic, then it does not seal the holes and the process goes without difficulty. If the mass is viscous and seals the holes, the machine works with overload and it is necessary to periodically turn off the motor and rinse the blades of the drum. The granulator contains a working chamber in which wet material to be granulated is fed through a feed funnel.