FORM 2
THE PATENT ACT 1970
(39 of 1970)
&
The Patents Rules, 2003
PROVISIONAL SPECIFICATION
(See section 10 and rule13)
1. TITLE OF THE INVENTION:
A MACHINE FOR THE MANUFACTURE OF A TABLET
2. APPLICANT (S)
(a) NAME: WOCKHARDT LTD
(b) NATIONALITY: INDIAN
(c) ADDRESS: Wockhardt Limited, D4-MIDC Area, Chikalthana,
Aurangabad - 431 210 (M.S.) INDIA.
3. PREAMBLE TO THE DESCRIPTION
The present invention provides a machine for the manufacture of tablet wherein the tablet comprises a bilayer tablet. The machine comprises positioning feed frame assembly first layer (1), positioning Feed frame assembly second layer (7), positioning powder scraper blades (2), positioning vacuum supply ( 6 & 9), positioning two sensor detections (3 & 5), positioning turret guard assembly (13) for pre compression of first layer so as to manufacture a tablet.
The following specification particularly describes the invention and the manner in which it is to be performed.
1

4. Description
There is an ever-increasing desire for combining active ingredients belonging to different therapeutic categories for better patient compliance and cost reduction. However, instability of the active ingredients poses a major obstacle in combining these active ingredients in a single dosage form. Drug instability is the phenomenon, which occurs when the effects of one drug are modified by the presence of another drug in the same dosage form. Therefore, combination dosage form which combines the features of pharmacologic efficacy, adequate drug stability, and a reliable and robust method of manufacture has to overcome a number of technical problems to be formulated in a single dosage form. Further, the standard approach of directly mixing the active ingredients with the necessary inert excipients cannot be applied to combination products of different active ingredients and more sophisticated techniques are needed to separate the different active ingredients in a single dosage form.
The present invention provides a novel tablet machine for the manufacture of a tablet comprising a bilayer tablet wherein standard approach of directly mixing the active ingredients with the necessary inert excipients cannot be applied to combination products of different active ingredients. Employing a bilayer tablet machine for the manufacture of bi layer tablet is already known. However, the bi layer tablet may comprise one active ingredient as one layer, a core tablet over this layer and the same active ingredient as the other layer. Alternatively, the bi layer tablet may comprise inert excipient as one layer , a core tablet over this layer and an active ingredient as the other layer. In both of the above cases of the manufacture of bi layer tablet, it would make sense if the manufacture allows prevention of the active ingredient of one layer getting mixed with the inert excipient or the active gradient of the other layer. Figure 1 gives examples of tablet dosage form of the present invention.


Further, commercially available tablet machines serve the purpose of the manufacture of tablets comprising bi layer tablet either manually or semi manually.
Hence, it is the objective of the present invention to devise a mechanism that allows the manufacture of the tablet comprising a bilayer and a "core tablet" with the avoidance of intermixing of either the two active ingredients or one active ingredient of one layer and the inert excipient of the other layer and also automate the tablet manufacture incorporating necessary sensors for prevention of intermixing of the active ingredients.
Related prior art of tablet machine are as described below.
US Patent 2,043,085 invention relates to rotary tableting machine and pertains to new and useful improvements in the principles of construction which result in economy of manufacture, greater convenience and efficiency of operation.
US Patent 3,663,147 provide a rotary press molding apparatus capable of high speed compression while compressing lamination.
US Patent 4,121,289 relates to controlling tablet formation and more particularly to measuring, displaying and recording the maximum compression force developed by a tablet press during tabletting and utilizing this information to tablet formation.
US Patent 4,168,137 relates to mechanism for applying radially directed compression pressure onto pharmaceutical materials in a tableting die.
US Patent 4,495,685 invention teaches, without limitations, a method for replacing the worn out spindle of a rotary tablet press.


US Patent 5,407,339 relates to a triturate tablet machine for making bevelled triturate tablets comprising, a frame, a table formed with a plurality of tablet holes rotatably supported by said frame etc.
US Patent 5,439,036 discloses a method and an apparatus provided for the automatic testing of tablets or pills, discharging from a tablet machine.
US Patent 6,787,082 relates to a punch for compressing powders to prepare tablets, which is characterized in that the surface of the punch is coated with Cr-Dope-N.
US Application 20020024166 Provide a punch or die having excellent corrosion resistance and releasing property which is suitable for a tablet machine particularly for the production of tablets.
EP0963836 relates to improvements in rotary machines for the manufacture of tablets, consisting on a rotary assembly with multiple moveable rods that act in the corresponding formation chamber.
EP1032493A1 relates to a compressing machine for tablets consisting in a main wheel along whose border are distributed several radial compressing couples composed by a counterfoil.
EP1266747A1 relates to a punch (4,6) or/and a die (3) for tableting using a cobalt alloy as a basis material has/have an excellent corrosion resistance appropriate as a tableting machine.
EP0963836B1 relates to rotary machine for the manufacture of tablets, consisting of a rotating portion (1) with multiple moveable rods.


The present inventors worked for a design of a tablet machine that caters to avoidance of intermixing of active ingredients in each other layer by carrying out suitable changes and modifications of the various components of an existing machine. The inventors have effectively been able to achieve this by positioning the various components of the tablet machine such as hopper, feed frame first layer, core tablet feeder plate, turret guard assembly for pre compression , feed frame second layer, powder scraper blades, core tablet feeder plate, two sensors and positioning the vacuum suctions on the turret.
One of the aspects of the present invention provides a machine for the manufacture of a tablet and the said machine comprises
(a) positioning (i) feed frame assembly (first layer) (1) (ii) Feed frame assembly (second layer)(7) comprising a hopper in each of the feed frame assemblies wherein each hopper comprise an active ingredient or an inert excipient
(b) positioning powder scraper blades (2) that touch the turret (11)surface to ensure no spill over of an active ingredient or an inert excipient as the rotating turret move on to the core tablet feeding stage (4) on the rotating turret.
(c) Positioning core tablet feeder plate (4) and determining the speed of rotation of the core tablet feeder plate (4) and the turret (11) such that the core tablet is charged over the active ingredient or an inert excipient wherein the direction of rotation of core tablet feeder plate (4) and turret (11) are in opposite directions
(d) positioning means of vacuum supply ( 6 & 9)over the turret surface (11) to suck out any left over active ingredient or an inert excipient
(e) positioning the two sensor detections, of which the first sensor (3) to detect and identify positioning of first feed layer and the core tablet and the second sensor (5) to detect and identify the missed core tablet and


activating no core rejection system to eject out the said identified and detected missed core tablet after the compression, (f) positioning turret guard assembly (13) for pre compression of first layer
"Turret" of a rotary tablet machine means a rotating table having number of dies for holding the substances that are transformed to a tablet comprising bi layer tablet and a "core tablet".
A typical machine with 20 number of stations can give tablet output of 12000 to 24000 per hour depending upon tooling size, shape and material characteristics.
A typical rotary tablet machine comprises a number of components of which some of the key components are main body, dies, punches lower & upper, Press rolls upper and lower, lower cam track assembly, upper cam track assembly, feed frame assembly, hopper assembly, discharge chute assembly, turret guard assembly for pre compression of an active ingredient or an inert excipient, turret etc.
Common tablets are prepared by compressing the active ingredients or inert excipients to form tablets by the use of punches and dies provided in a tablet machine. Briefly, the machine is constituted as follows: die bore is perforated in dies provided in a die table; height of lower punches provided at lower side in the die bore is adjusted so that respective spaces in the holes have a predetermined volume; an active ingredient or an inert excipient for are filled in the die bore; the active ingredient or the inert excipient is compressed with upper punches to form tablets; and the tablets are pushed upward by the lower punches to eject the tablets from the die bore.
The above-described punches are not to be deformed easily, and a high mechanical strength is required for punches. Therefore, they have been


conventionally made of super steel alloy or alloy tool steel. In addition, punches having chrome plating layer or the like on the punch surface are also used as a measure against corrosion.
The various important operations of a typical tablet machine are described below.
Motor is switched on & off by a switch button and the speed is controlled by a gear mechanism. Hand wheel allows operation and adjustment of pressing speed.
Adjustment of flow of pressing material is accomplished by operating a knurled screw. Hand wheel serve towards adjustment of upper filling only.
Lower pressure roll will be under spring tension. There is a mechanism for ejection of an incorrect tablet by a smaller or larger movement of a lever. Storage unit rotation in synchronization with die plate and the accompanying condenser charging by a tracer device enables ejection.
The filling of the die is effected from a hopper via feed frame with the chambers. Screw adjustments enables adjustment of the pressing material.
The core tablets are fed to the feed plate from a vibratory hopper through two glass or plexi-glass tubes. The cores are then fed from the feed plate into the dies. One individual feed plate and one individual set of tube are necessary for each core diameter.
Adjustment of a typical tablet machine to cater to double-layer tabletting machine requires the following modifications.
Removal of vibratory hopper, alimentary tube, feed plate including feed plate gear, fill shoe with hopper, support & bolt.


Insertion of shorter bolts at the full shoe supports. Replacing tablet scraper and bolts by the simple scraper with bolts. Mounting special shoe for double -layer tablets. Subsequently the suction device is mounted.
One of the aspects of the invention is to manufacture a machine for the manufacture of a tablet wherein the tablet dosage comprises bi layered tablet and a "core tablet".
The machine for the manufacture of the tablet wherein feed frame assembly (first layer) comprises a hopper wherein an active ingredient or an inert excipient is stored.
The machine for the manufacture of the tablet wherein feed frame assembly (second layer) comprises a hopper wherein an active ingredient or an inert excipient is stored.
The machine for the manufacture of the tablet wherein turret is a rotating table having a number of dies or stations as commonly known for holding the active ingredient or inert excipient. Typical tablet manufacturing machines will have varied number of dies. One of the tablet machines of embodiment ( Figure 2) for which modification is effected has 20 dies or stations.
The machine for the manufacture of the tablet wherein the vacuum sucks out the substances on the turret avoiding no mix up between the active ingredients or the inert excipients and each tablet layer is free of the active ingredient or the inert excipient of the other layer. Use of vacuum for sucking out active ingredient or the inert excipient is a well known feature but the position of the vacuum on the modification effected on the tablet machine is with a particular purpose. In addition to scraper blade functioning to remove the spilled first substance, vacuum suction serves to suck out any possible remnant of the active ingredient


or the inert excipient being carried over and mixed up with the active ingredient or the inert excipient. Second layer vacuum suction (9) serves to suck out any possible remnant of second layer active ingredient or inert excipient being carried over to first layer active ingredient or inert excipient charging zone. Second layer vacuum suction (9) is positioned strategically after the press roll.
The machine for manufacture of the tablet wherein first sensor (3) acts to detect and identify proper positioning of first feed layer and the core tablet.
The machine for manufacture of the tablet where in the second sensor (5) detects and identify the missed core tablet and activating no core rejection system (10) to eject out the said identified and detected missed core tablet after the compression.
The machine for manufacture of the tablet where in the second sensor ensure identifying the missed core tablet and ejecting out the tablet at no core rejection system (10).
The machine for manufacture of the tablet where in turret guard assembly (13) for pre compression of first layer is positioned before the charge of the second layer active ingredient or inert excipient.
Figure 2 shows the schematic of modification for a tablet machine.
One of the embodiments of a typical tablet machine comprises a number of components of which some of the key components are main body, dies, punches lower & upper, lower cam track assembly, upper cam track assembly, feed frame assembly (1 & 7), Press rolls (8) upper & lower, hopper assembly, discharge chute assembly (12) , turret guard assembly (13) for pre compression of first active ingredient or excipients, turret (11) etc.


Achievement of the invention objective of automated manufacture of the incorporating highest safety factors as not to allow any chances of mixing of the active ingredient or excipients howsoever small it could be, or no mixing at all, require a number of modifications of the tablet machine components.
Components such as main body, turret (11) & discharge chute assembly (12) would be retained with almost no modification.
Design changes in the number of components required and their positioning in the already available machine are essential and have been brought out. The design changes that have been brought out keeping in mind the consideration of time & cost involved in designing and manufacturing the changed components at the manufacturer's site.
Positioning of feed frame assembly (first layer) (1) and feed frame assembly (second layer) (2) have been determined considering core tablet positioning after the first layer. Feed frame assembly (first layer) (1) is modified with an incorporation of scraper blade (2). Feed frame assembly first layer (1) is provided with a modified vacuum facility for sucking out any spilled over second layer active ingredient or excipient.
There is a provision for pre compression(13) of first layer with core tablet.
The Turret(11) rotates in one direction and the core tablet feeder plate (4) rotates in the other direction. If the Turret (11) rotates in the clockwise direction the core tablet feeder plate (4) rotates in the anticlockwise direction. In the embodiment shown in figure 2, the turret rotates in anti clockwise direction. The Powder scraper(2) provided over the turret (11) surface enables restriction on spill over of the first active ingredient or the excipient as the case may be beyond the zone of first charging zone.


Core tablet placement is ensured over the first the active ingredient or the excipient as the case may be in the automated tablet production of the tablet comprising a bi layer and the core tablet. Certainty of this is ensured by providing a sensor (3) which detects and identifies the gap if any between the die containing the first substance and the core tablet feeding (4). A corrective action is necessitated to ensure the core tablet is charged into the die in case of discrepancy.
Speed of rotation of the core tablet feeder plate (4) and the turret (11) are such that core tablet gets placed over the first active ingredient or the inert excipient in the continuous rotation of both the turret (11 )and the feeder plate(4).
It is necessary not only to ensure proper placement of the core tablet over the first active ingredient or the inert excipient but also it is loaded. This is ensured by the second sensor (5) which detects, identifies and takes corrective action by ejecting out the compressed tablet if either the core tablet is not positioned properly or it is missed. The ejected tablet moves out of no core rejection system (10). The tablet ejection chute (12) is located after the no core rejection system(10).
The press roll (8) compresses the tablet and the compressed tablet ejects out at ejection chute (12).
Position of (i) feed frame assembly ( first layer) (1), (ii) feed frame assembly ( second layer) (7) accompanied with modification of providing scraper blade(2) and vacuum system (6 & 9) respectively, (iii) turret guard assembly for pre compression of first layer (13) and (v) sensors both first and second ones (3 & 5) (vi) no core rejection system (10)
as shown in Figure 2 are essential and this has necessitated the modification of (v) lower cam track assembly and (vi) upper cam track assembly.


The changed movement pattern of lower punches and upper punches by virtue of changed position of the components described earlier has resulted in the requirement of carrying out modifications to lower cam track assembly and upper cam track assembly.
The entire operation tablet machine is controlled by programmable logic controller (PLC) assembly. A separate PLC panel box assembly is provided for the same.


We Claim
1 A machine for the manufacture of a tablet and the said machine
comprises
(a) positioning (i) feed frame assembly (first layer) (1) (ii) Feed frame assembly (second layer)(7) comprising a hopper in each of the feed frame assemblies wherein each hopper comprise an active ingredient or an excipient.
(b) positioning powder scraper blades (2) that touch the turret (11)surface to ensure no spill over of an active ingredient or an excipient as the turret move on to the core tablet feeding stage (4) on the rotating turret.
(c) positioning core tablet feeder plate (4) and determining the speed of speed of rotation of the core tablet feeder plate (4) and the turret (11) such that the core tablet is charged over the active ingredient or an excipient wherein the direction of rotation of core tablet feeder plate (4) and turret (11) are in opposite directions.
(d) positioning means of vacuum supply ( 6 & 9)over the turret surface (11) to suck out any left over active ingredient or an excipient.
(e) positioning the two sensor detections, of which the first sensor (3) to detect and identify proper positioning of first feed layer and the core tablet and the second sensor (5) to detect and identify the missed core tablet and activating no core rejection system to eject out the said identified and detected missed core tablet after the compression.
(f) positioning turret guard assembly (13) for pre compression of first layer.
(2) The machine for manufacture of the tablet of claim 1 wherein the tablet dosage comprises bi layered tablet.


(3) The machine for manufacture of the tablet of claim 1 wherein turret (11) is a rotating table and having a number of dies for holding the active ingredient or the excipient.
(4) The machine for manufacture of the tablet of claim 1 wherein the scraper blade (2) is mounted on the turret.
(5) The machine for manufacture of the tablet of claim 1 wherein the vacuum sucks out the active ingredient or the excipient on the turret ( 6 & 9)
(6) The machine for manufacture of the tablet of claim 1 where in the first sensor (3) ensure positioning of the active ingredient or the excipient and the core tablet.
(7) The machine for manufacture of the tablet of claim 1 where in the second sensor (5) ensure presence of core tablet over the active ingredient or the excipient and / or its positioning and identifying the missed core tablet and ejecting out the tablet at no core rejection system.
(8) A machine for manufacture of tablet as herein described in Figure 2