EP1693182B1 - Method and apparatus for the trial pressing of multi-layer tablets or coated tablets - Google Patents

Description

The invention relates to a method for the test squeezing of at least two layers of tablets according to claim 1 in the experimental squeeze of coated tablets according to claim 2 and an apparatus for performing the method according to claim 6.

Rotary tablet presses are known to have a rotary drive driven rotor having a die plate, top and bottom punches guided in respective guides and having a cam system. Furthermore, at least one pressing station is provided, which usually has an upper and lower pressure roller, with the aid of which upper and lower punches are pressed into the matrix in when you pass the pressing station. Usually, two pairs of pressure rollers are provided for pre-pressing and final pressing of the material. Finally, a filling device is provided, by means of which the material to be pressed is filled into the die holes. The rotor is continuously rotated, with the filling device constantly filling material in the associated die bores and the associated lower punch ejects the finished pressed tablet from the die bore, from where it is guided by means of a scraper in a channel.

It is also known to produce multilayer tablets with such rotary tablet presses. The multilayer tablets are produced in one revolution of the rotor, wherein one filling device per layer and a pressure roller assembly (pressing station) is provided. If z. B. produces a three-layer tablet, three filling devices are provided at 180 ° distance and three pressing stations with at least one pressure roller pair between the filling devices.

It is also known to produce so-called coated tablets with the aid of a rotary press. Under coated tablets is usually understood a two-layer tablet in which a core is disposed between the layers. After filling and pressing the first layer, a core of another material is placed on the first layer and then a second layer is filled. In the production of such coated tablets can be proceeded in various ways. It is conceivable to refill the first layer and to carry out a compression only when the second layer is filled. Alternatively, the first layer can be pressed before the core is inserted. Subsequently, the compression of both layers with core. Finally, it is also possible to press the core after insertion a degree in the first layer. This can also be done with the upper punch in the pressing station. The processes described can take place during one revolution of the rotor.

It is known to associate such tablet presses with a measuring device which records essential data during production and processes them in an operating computer. These include the rotational speed of the rotor, the maximum pressing forces in the pressing station and optionally the pressing force curve in the pressing station, namely the individual pairs of punches associated. By subsequently measuring the ejected tablets in terms Weight, thickness and hardness are used to determine if the desired parameters have been achieved. If not, the filling quantity, pressing force or other parameters must be changed. Apparatus and methods for controlling the tablet presses to achieve optimum results are known in the art.

In the development of tablets, among other things, the compression characteristics of the material to be pressed are determined. For this purpose, initially only very small amounts of product are available, which can also be very expensive to manufacture and material, so that the product losses must be kept small during the pressing. It is known to perform press trials with special laboratory presses. These are usually smaller eccentric presses, in which one tablet can be produced for each pressing process. The disadvantage is that the laboratory presses have a different pressing behavior than rotary tablet presses, which are used for production. Press trials with a production rotary press naturally have the advantage that the data determined during the tests can be transferred directly to the production. The disadvantage is that a filling arrangement, as normally used, must be constantly filled uniformly so that it has a sufficient volume with a basic amount of pressing material, even if only a small number of tablets are produced. Out DE 103 19 024 B3 For example, a method for test-pressing tablets with a rotary tabletting machine has become known, in which a pair of stamps selected for a single pressing is automatically moved to a filling position and at least one die is filled with the material to be pressed.

Subsequently, the rotor is rotated and accelerated so that it has the desired production speed in the printing station. After one revolution, the rotor is stopped in the filling position. During the rotation of the rotor signals or waveforms of the measuring points are recorded and placed in a computer for display and evaluation.

The conditions as described in connection with tablet test dressings are exacerbated in experimental pressings of multilayer or coated tablets. As already mentioned, a rotary press in multilayer tablets requires several filling and pressing stations, depending on the number of layers of the tablet.

In EP-A-0 572 816 describes a method for pressing two-layer tablets in a double rotary press, in which the tablets pressed layer by layer and the two-layer compacts are then ejected in a removal station and removed. The compacts produced in the test sections after the compression of the first layer are removed in an intermediate sampling station and fed to a test station, wherein the first layers are precompressed more strongly before sampling in the intermediate sampling station than during normal production. The further compressed second layers are fed to a bad channel or also the test station at the latest after removal of the single-layer compacts in the removal station. The document EP-A 0 572 816 also discloses a device according to the preamble of claim 6.

The invention has for its object to provide a method for the test-molding of multi-layer or coated tablets, on the one hand under Production conditions is feasible and on the other hand manages with little press material.

This object is solved by the features of claim 1 or patent claim 2, as well as by the device of claim 6.

In the method according to the invention, the rotor is provided with a pair of punches and with the aid of the operating computer and control computer, the rotor can be moved to a defined filling position in which the pair of punches is in this position. The lower punch is in a first fill position while the ejector cam is in an inactive position. The template is filled with the material for the first layer.

It should be mentioned that the pressure rollers have taken a first printing position in the pressing station. The adjustment of the control cams and the pressure rollers is done with the aid of suitable adjusting drives, such as a hydraulic or pneumatic or electromechanical drive. Subsequently, the rotor is rotated by one turn until the pair of dies has reached the filling position again. This is done a pressing of the first layer of the multilayer tablet. Since the ejection cam has been in an inactive position, the first layer is not expelled, but remains in the die bore. After reaching the filling position again, the filling curve is brought into a position in which a metered filling of the second layer of the multilayer tablet can take place. Before a second revolution of the rotor, the pressure rollers are brought into a second printing position. Further, the ejector curve is brought into an ejector position when only a two-layer tablet is to be produced. During the second revolution of the rotor, therefore, the second layer is pressed and ejected the two-layer tablet through the Auswerferkurve and the associated lower punch. For the production of a multilayer tablet with n layers therefore n rotations of the rotor d. H. One revolution per shift required with each individual adjustment of the cams and the pressure rollers.

If a three-layer tablet is produced, three rotations of the rotor are required using the steps described above. Only at the third revolution is then the ejection of the three-layer tablet using the lower punch.

During the respective revolutions of the rotor, the signals of the individual measuring points, z. B. for the pressing force, recorded and fed to a control computer for display and evaluation. The measured signals serve z. B. for determining the compression characteristic of the press material.

By a suitable control of the computer, it is also possible to produce automatically several multilayer tablets in a row, wherein after each revolution, the described process parameters can be automatically adjusted and changed. The number of layers of a tablet is theoretically unlimited.

The process for producing a coated tablet is similar to the method according to claim 1. First, a first layer is filled and preferably "pressed". At the next stop after one revolution of the rotor, the core is inserted. This can be pressed in a further revolution of the rotor with the help of the upper punch a little in the lower layer. However, it is also possible first to fill the core and then the second layer at the same stop of the rotor in the filling station. Subsequently, the rotor makes one revolution, in which the two layers are pressed together with the core to the finished tablet. Subsequently, as already described above, the ejection of the coated tablet.

The filling of the press material and the core can be done by hand. However, it is also possible to provide a filling device. An embodiment For this purpose, the invention provides, for example, a filling device rotatable about a vertical axis, which has a chamber for receiving a layer material per layer of the multilayer tablets. Upon rotation of the filling device by means of z. B. a rotary drive, in each case a filling outlet of a chamber is aligned with the die bore in the filling position.

The inventive method has a number of advantages. Press tests could be carried out with a rotor fitted with only one pair of punches, with or without dummy dies. The changeover times to other press materials or other stamp types is very short. In the press trials, a low dust formation, since only small amounts of material are used.

The material losses are extremely low, since only one die hole is filled with the layer material. All process-relevant settings can be adjusted and tested in the press trials: speed of the rotor, pressing force in the press station, thickness, hardness and weight of the tablets, etc. The data determined in the press trial and various settings can be transferred directly to a production rotary press, such as z. As the speed, the pressing force, thickness, hardness, weight of the tablets, etc. The measurement data for each pressing process are available directly and can be displayed in the operating computer, evaluated and stored with all process-related data.

Fig. 1

zeigt die Draufsicht auf eine Druckstation und einen Rotor einer Rundläufer-Tablettenpresse nach der Erfindung.

Fig. 2

zeigt schematisch in der Abwicklung die Herstellung einer Dreischichttablette mit der Rundläufer-Presse nach Fig. 1.

The invention will be explained in more detail with reference to an embodiment.

Fig. 1

shows the top view of a printing station and a rotor of a rotary tablet press according to the invention.

Fig. 2

shows schematically in the development of the production of a three-layer tablet with the rotary press after Fig. 1 ,

In Fig. 1 is a rotor 10 of a rotary tablet press indicated with a die plate 12 having a plurality of die holes 14 on a pitch circle. The rotor 10 is driven by a suitable rotary drive, which in turn is controlled by an operating computer and control computer (not shown). The rotor 10 are two pressing stations 16, 18 associated with upper and lower pressure roller, in each case only an upper pressure roller 20 and 22 can be seen. With the help of the pairs of pressure rollers, upper and lower punches are pressed into the die bores 14 when they pass over or under the pressure rollers in order to press the material located in the die bore.

In the invention, the rotor is associated with only one pair of punches, namely upper and lower punches, which in turn are associated with only one die bore 14. The stamp pair is in Fig. 1 not shown.

The rotor 10 is associated with a filling device 24. It is rotatable about a vertical axis, as indicated by the arrow 26. The rotation can be done by means of a suitable, not shown here rotary drive. The filling device 24 has three filling chambers 28 arranged at 180 ° intervals on, the filling output can be aligned depending on the rotational position to a die bore 14. In the manufacture of a three-layer tablet, each filling chamber 28 is filled with a material for a layer of the three-layer tablet.

In Fig. 2 is the above-mentioned press-stamp pair shown seven times. The upper punch is denoted by 30 and the lower punch by 32. It also recognizes the die 34 with the die bore 14, which are associated with the punches 30, 32. In the Fig. 2 The seven positions shown correspond to three revolutions of the rotor 10. In position 1, the pair of punches 30, 32 are in the filling position, and the rotor 10 is at a standstill. By hand or by means of the filling device 20 after Fig. 1 a first amount of material 36 is filled into the die bore 14. The amount is therefore determined by the position of the lower punch 32, which is brought with a filling curve 38 in the desired position. In positions 2, 4 and 6, the pressing operation takes place in which the pressing punches 30, 32 pass between upper pressure roller 18 and lower pressure roller 19 (in FIG Fig. 2 is the sake of simplicity, the pressure roller pair of the pressing station 16 in Fig. 1 omitted). In position 2, thus, the first layer of a three-layer tablet is pressed. After the first revolution, the rotor 10 is stopped again in the filling position of the press-punches 30, 32 and it is filled with the material 38 for the second layer. In position 4, the second layer is pressed, and in position 5, the filling is carried out with a third layer of material 40, which is also pressed in position 6 to form a multilayer tablet, which is designated in position 7 at 42 and the lower punch 32 is ejected from the die bore. For this purpose, an ejector 44 is provided.

Before each filling or each pressing operation, filling curve 38 and pressure rollers 18, 19 are set in the desired manner in order to specify the required pressing parameters. The adjustment is made by means of suitable adjustment drives, which are not shown here. However, it is understood that, depending on the number of desired over-rotation very well an adjustment before the next revolution of the rotor and the next pressing process takes place. The Auswerferkurve 44 also has an adjustment (not shown), which the Auswerferkurve 44 during the first two revolutions to Fig. 2 adjusted to an inactive position to avoid ejection of the previously pressed layers.

The control of the individual adjusting drives and the rotary drive for the rotor 10 and the filling device 24 is carried out by an operating computer and control computer such that, after appropriate programming or before setting, these processes take place automatically. A suitable measuring device, which is not shown here, registers various process parameters, such. B. rotational speed of the rotor 10, pressing force on the pressure rollers 18, 19, etc., which can then be processed in the operating computer in a suitable manner to z. For example, change the settings at the next trial press.

Claims (7)

1. A method for test pressing tablets consisting of n layers in a rotary tablet press under production conditions, said rotary press comprising a rotationally driven rotor (10) with die bores (14), punch guides, at least one press station (16, 18) and a control cam system, wherein the control cam system comprises inter alia a filling cam (38) and an ejection cam (44) for the lower punches (32), and wherein the pressure rollers (20, 22) of the press station (16, 18) and the control cams are adjustable in height by suitable adjustment drives, comprising the following steps:

   - the rotor (10) provided with an upper punch (30) and a lower punch (32), i.e. pair of punches is moved with the pair of punches into a defined filling position, in which the die bore (14) associated with the pair of punches is filled with the material for the first layer of the tablet, wherein the filling cam (38) is moved into a first position, the ejection cam (44) is moved into a lower position, and pressure rollers are moved into a first pressing position by means of associated adjustment drives;

   - then the rotor (10) is rotated by a full revolution and the pair of punches is stopped in the filling position;

   - the filling cam (38) is adjusted to a second filling position and the pressure rollers are adjusted to a second pressing position;

   - thereafter the first die bore (14) containing the first layer is filled with the material for the second layer; and

   - the rotor (10) is rotated by a further full revolution and the pair of punches is stopped again in the filling position, and so forth;

   - at the n-th revolution of the rotor (10), the ejection cam (44) is adjusted to the ejection position and the lower punch (32) ejects the multi-layer tablet.
2. A method for test pressing tablets (coated tablets) under production conditions, which are composed of two layers and one core disposed between the layers in a rotary tablet press, said rotary press comprising a rotationally driven rotor (10) with die bores (14), punch guides, at least one press station (16, 18) and a control cam system, wherein the control cam system comprises inter alia a filling cam (38) and an ejection cam (44) for the lower punches (32), and wherein the pressure rollers of the press station (16, 18) and the control cams are adjustable in height by suitable adjustment drives, comprising the following steps:

   - the rotor (10) provided with an upper punch (30) and a lower punch (32), i.e. pair of punches is moved with the pair of punches into a defined filling position, in which the die bore (14) associated with the pair of punches is filled with the material for the first layer of the tablet, wherein the filling cam (38) is moved into a first position, the ejection cam (44) is moved into a lower position and pressure rollers are moved into a first pressing position by means of associated adjustment drives;

   - then the rotor (10) is rotated by a full revolution and the pair of punches is stopped in the filling position;

   - in the filling position, a core is placed in the die bore (14) on the first layer;

   - a second layer is filled into the bore, either after placing the core in the die bore (14), or when the filling position is reached again after a revolution of the rotor (10);

   - the second layer is pressed at a full revolution of the rotor (10) in a second pressing position of the pressure rollers (20, 22) and the pair of punches is stopped again in the filling position;

   - at the last revolution of the rotor (10), the ejection cam (44) is adjusted to the ejection position and the lower punch (32) ejects the coated tablet.
3. The method according to claim 1 or 2, characterized in that during each revolution of the rotor (10), the pressing force values are recorded and transferred online to an operating computer for the rotary tablet press.
4. The method according to claim 1 to 3, characterized in that the drive means for the rotor (10) is dimensioned such that it has production speed in these ranges of the pressure roller station.
5. The method according to claim 2, characterized in that the core is pressed by means of the pressure rollers into the first layer, when the rotor (10) rotates with a first layer and the core on the first layer.
6. An apparatus for test pressing tablets consisting of at least two layers in a rotary tablet press, comprising a rotationally driven rotor (10) with die bores (14), punch guides for upper punches (30) and lower punches (32), a press station (16, 18) exhibiting pressure rollers (20, 22), and a control cam system, wherein the control cam system comprises inter alia a filling cam (38) and an ejection cam (44) for lower punches (32), and wherein the pressure rollers (20, 22) and the control cams are each adjustable in height by a suitable adjustment drive, and wherein an operating computer is provided for controlling the single components of the rotary press, characterized in that the rotor (10) contains only one upper punch and one lower punch (30, 32), i.e. pair of punches the operating computer is programmed such that the pair of pressing punches (30, 32) is automatically movable into a defined filling position, in which the lower punch (32) is movable into a desired filling position by means of its filling cam (38), the ejection cam is movable into an inactive position by its adjustment drive, that further a filling device (24) is provided which is rotatable about a vertical axis which comprises a chamber (28) per layer of the multilayer tablets for receiving a layer material, and wherein by rotation of the filling device (24) one filling outlet each of a chamber (28) with a die bore (14) can be aligned in the filling position.
7. The apparatus according to claim 6, characterized in that a rotary drive for the filling device (24) is provided, which is controllable by the operating computer and the control computer.

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