Pharmaceutical technologies | THE CHAPTER 14

Chapter 14  Methods of drawing film Coverings. Napressovannye coverings. Trituratsionnye tablets.
 Methods drawings of film coverings.
Drawing film coverings is carried out in drageeing Boilers, installations of centrifugal action and in psevdoozhizhennom A layer. The method of drawing of coverings in psevdoozhzhennom a layer is applied For drawing water coverings, as drageeing boilers Have low parameters warmly and massoperenosa and process Coverings proceeds slowly, that reduces productivity The device. Use of water coverings has a number of advantages: Disappears necessity of catching and regeneration of solvent; To prepare for water solutions it is easier, they it is better distributed on Surfaces of tablets. For film water coverings use Water solutions oksipropilmetplTS, ammonijnyh salts of shellac and atsetilftalilTS. Before drawing of water coverings of a surface Tablets give water repellency at the expense of drawing a layer Vegetable oil. The device for drawing water film Coverings it is developed LNPO "Progress".
At impossibility of use of a water film covering The covering is applied on the basis of organic solvents. For Drawings these coverings use drageeing boilers. This The method is simple, differs high efficiency at Use of coverings on the basis of organic solvents. For Drawings a covering biconvex tablets are loaded in The drageeing boiler. Before the beginning of process of a covering with Surfaces of tablets the dust (with the help of an air jet leaves Or vacuum). The covering solution is entered in the boiler by Repeated razbryzgivanija (with the help established at Apertures of the boiler of an atomizer).
For drawing film coverings on the basis of organic Solvents installation ÓÇÖ-25 having closed is applied System of catching and regeneration of solvent.
Installation ÓÇÖ-25 works as follows: in drageeing The boiler rotating from a drive, are loaded subject to a covering Tablets. The system is isolated. In the collection prepares covering A solution. The system of pipelines is filled by nitrogen. The fan Nitrogen moves in a heater where it is heated up up to set Temperatures, then, entering into the boiler, washes mixed Tablets on which with the help raspylivatelja it is rendered A covering solution. Nitrogen with pairs solvent acts in The condenser where solvent is condensed and going to in The collection. The drained nitrogen again acts on the fan. This The cycle repeats repeatedly up to a full covering of tablets. On The termination of process it is made razgermetizatsija a casing The drageeing boiler, for what preliminary from system with The help of vacuum nitrogen with pairs solvent leaves. The boiler Opens, the rest parogazovoj knead leaves from the boiler local The pump. A covering of a tablet are unloaded by an inclination of the boiler. The weight of the tablets loaded in the boiler, makes 25 kg. Duration of a cycle no more 4÷.

Napressovannye coverings.
Napressovannye coverings are the dry coverings rendered on Tablets by pressing by special machines (ÐÒÌ-41Ä), Which represent a combination of two machines: rotational- Usual type for pressing tablets and special - for Receptions on them napressovannogo coverings. On the first rotor Tablets which the passing device go are pressed On the second rotor in which matrix the covering solution moves And the tablet is pressed finally. Principal causes, Constraining wide application of this method, are more Low characteristics of coverings in comparison with plenkami and less An attractive packaging.

Trituratsionnye tablets.
Trituratsionnymi the tablets formed from humidified are called Weights by her vtiranija in the special form with the subsequent Drying. As against pressed, trituratsionnye tablets not Treated to action of pressure: coupling of particles of these tablets It is carried out only in result autogezii at drying, Therefore trituratsionnye tablets possess smaller durability, than Pressed. Trituratsionnye tablets make in those Cases when use of pressure is undesirable or It is impossible. It can take place when a dosage Medicinal substance it is small, and addition of a plenty A plenty of auxiliary substances it is inexpedient. To make such tablets because of the small size (d = 1-2 mm) on To the machine it is technically difficult for a tablet. Trituratsionnye tablets Make and when action of addition can call to - l change of medicinal substance. For example, at reception Tablets of nitroglycerine at use of addition can To take place explosion. And more trituratsionnye tablets expediently To be going when tablets, quickly are necessary And it is easy rastvorjajushchiesja in water. For their manufacturing are not necessary Sliding substances which are insoluble Connections. Trituratsionnye tablets are porous and Fragile and consequently they are quickly dissolved at contact with A liquid that is convenient by manufacture of tablets for injections and Eye drops.
As auxiliary substances for trituratsionnyh tablets Use lactose, saccharose, glucose, kaolin, ÑàÑÎ3. At them Reception poroshkoobraznuju the mix is humidified with 50-70 % spirit up to Receptions of plastic weight, which then with the help shpatelja Rub in a plate - a matrix placed on glass. Then with Damp tablets are pushed out by the help of pistons of punches from Matrixes also are dried on air or in a drying case at To temperature 30-40? C. On other way drying of tablets It is carried out, it is direct in plates and with the help Punches dried already up tablets are pushed out.

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