Form-2
THE PATENTS ACT, 1970
(39 of 1970)
COMPLETE SPECIFICATION
[See section 10]
AN JMPROVED METHOD AND APPARATUS FOR BAND SEALING HARD CAPSULES;
SCITECH CENTRE, A COMPANY INCORPORATED UNDER SECTION 25 OF THE COMPANIES ACT, 1956, WHOSE ADDRESS IS 7, PRABHAT NAGAR, JOGESHWARI (WEST), MUMBAI - 400 102, MAHARASHTRA, INDIA;


THE FOLLOWING SPECIFICATION
PARTICULARLY DESCRIBES THE
NATURE OF THIS INVENTION AND THE
MANNER IN WHICH IT IS TO BE
PERFOMED.

TITLE :
AN IMPROVED M ETHOD A ND APPARATUS F OR B AND SEALING HARD CAPSULES;
FIELD OF INVENTION:-
The present invention relates to a process and apparatus for sealing hard capsules filled particularly with a dose of liquid product such as liquid medicine. This invention may also be applicable to -hard capsules filled with material other than liquid.
BACKGROUND OF THE INVENTION:-
As is generally known in the art, capsules made out of gelatin for use in pharmaceutical industry are classified into hard capsules and soft capsules.
Commonly, powdered or granular substances are filled into hard capsules, while liquid products such as oils medicines are filled into soft capsules.
As compared with medicines, such as powdered or granular medicines, liquid medicines generally have advantages such as easiness in uniform dispersion of the active component in a carrier employed, precise distribution of the mixture obtained and better bio¬availability. Therefore, there has been an increase in trend found apparently in the pharmaceutical industries in the recent years to deliver medicines preferably in liquid form.

As regards the soft gelatin capsules, filling-in and packing of liquid products have been found to be less economically feasible, when
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compared to that effected using hard gelatin capsules.
The two-piece, telescopic, empty, hard gelatin capsule is normally called simply as " HARD GELATIN CAPSULE". It is a precision -engineered dosage form consisting of two elongated, cylindrical, pliable shells. Both the shells are closed at one end in the shape of hemispherical smoothly contoured dome and are open at the other end. They are slightly tapered outwardly towards their open ends. Among the two shells, the one which is bigger in diameter but shorter in length is called " CAP" and the other which is smaller in diameter but longer in length is called ! BODY". The inner diameter of cap at its dome base is kept slightly less than the outer diameter of body at its cut end. Due to outward taper towards cut end, the inner diameter of cap at its cut end is slightly bigger than the outer diameter of body at its cut end, thus facilitating smooth entry of the body into the cap at the time of joining. When joined (telescoped) together, the open end of" BODY " fits perfectly at the dome base of " CAP' to form the empty gelatin capsule.
The term ' Hard Gelatin Capsule" is used herein for the purposes of illustration only.
In this application, when the term gelatin is used, it is also understood to include other polymers with properties similar to gelatin. The teachings of this application might be applicable also for

Hydroxypropylmethyl cellulose (HPMC) capsules and various other cellulose derivatives, enterosoluble capsules, PVA, starch.
Numerous attempts have been made over the years, to deliver liquid products such as liquid medicines, oils and similar viscous materials, successfully through the hard gelatin capsules for various applications namely for pharmaceuticals, agrochemicals and cosmetics or any other applications.
Hard gelatin capsules, by virtue of their telescopic joint, are vulnerable to liquid leakage.
Therefore, a complete sealing of the cap and the body joining portions of the hard gelatin capsule, is required for delivering liquid products without facing the problems of potential leakage.
An earlier attempt to develop a capsule sealing machine, was made by A. Colton & Company, to seal the joined portions of the cap and the body of hard gelatin capsules filled with powder, at high speed by applying a visible band of gelatin around the cut end of a cap of a capsule, thereby preventing the leakage of powder from the joint. The colored band was also used for product and identification purposes. However, the art of band sealing the capsules was also extended to liquid filled hard gelatin capsules.
The US Patent No. 5,930,984. issued to Shionogi & Co., Ltd., Japan, entitled "method for forming a band seal on a capsule" teaches an invention wherein a band seal is formed between the body and the cap of a capsule by fitting the cap on the body and applying a gelatin-base

sealant at least one time in the form of a band around the cut end of cap of a capsule. According to the invention as disclosed by the US Patent No. 5,930,984, band sealing is carried out by at least one of.the following steps (A) to (E) wherein;
The s tep (A) o f a pplying t he s ealant at a t emperature of 3 0-40°C a t least when the sealant is first applied.
the step (B) of applying the sealant at a viscosity of 50-200 centipoises at 40 degree C at least when the sealant is first applied.
the step (C) of after the sealant is applied, blowing cold air at a temperature of up to 10°C to the band seal to cool the band below 10°C, the step (D) of reducing the joint distance between the body and the cap shorter than the standard capsule length and the step (E) of applying the sealant to only an edge adjacent portion of the cap surface when the sealant is first applied.
By the above band sealing method, the obtained capsules are found to be free from any bubbles being generated in the said band seal and thereby resulting in uniform sealing surface.
The US Patent No. 4,532,881 issued to Eisai Co., Ltd., entitled process for sealing body and cap of gelatin hard capsule and apparatus therefore discloses an invention wherein the capsules are successively dipped in a mixed volume of water and ethanol whose volume ratio to water is 50-55%, and thereafter the capsules are taken out of the solvent and dried successively in cold and hot air drying zones. The

teachings of the US Patent No. 4,532,881 suggest production of crushing free and distortion free capsules.
From the foregoing description, it may be clearly understood, that the above prior art methods and apparatus have found solution to various problems associated with the band sealing of hard gelatin capsules filled with liquids and viscous materials.
But none of them appear to have sufficiently addressed the problem of distortion in band sealing area at the joining area of the body and the cap of a hard gelatin capsule particularly, in liquid filled capsules where the bending problem is apparent such that it hampers the packing line.
Our inventors by the dint of determined research and their intuitive knowledge have identified that in liquid filed hard capsules, the primary cause of generation of distortion is due to the applied band seal, in liquid state. Our inventors have found that immediately after application of wet gelatin band around the capsule, the band tends to run down from the surface forming an uneven mass, thereby resulting in an uneven setting. Further, once the applied wet gelatin runs down form the surface, there exists a tendency of the applied gelatin band getting unevenly distributed over the cap and body joining surface and due to such uneven distribution, the entire capsule tends to bend or sag about its axis in due course of time.
Our inventors, in an attempt to find a solution to the foregoing problem, have surprisingly found that when the capsules are rotated about their own axis subsequent to the application of the wet gelatin band seal,

the tendency of the wet gelatin band to run down from the surface of the capsule, becomes much more reduced. Also, when the capsules are rotated subsequent to the application of wet gelatin, the gelatin gets uniformly distributed over the sealing area of the capsule. Simultaneously, cold air is blown so that uniformly distributed wet gelatin band gets uniformly set around the capsule.
OBJECTS OF THE INVENTION :-
It is the primary object of the present invention to identify and find successful solution to the core problem associated with distortion generation in the sealing area of the hard gelatin capsules filled with liquid and also with the capsules filled with powders where bending is observed to some extend.
An object of the present invention is to nullify the bending of capsules due to the band sealing and thereby obtain distortion free capsule.
BRIEF DESCRIPTION OF DRAWINGS
To complement the invention that is being given and in order to promote a better understanding of the characteristics of the invention in accordance with a practical embodiment of the same and as an integral part of the said description a set of drawings accompany it in which in an illustrative and non-restrictive way the following are represented:
Fig 1 is the front of the assembly comprising the rotation generation means in accordance with the present invention.

Fig 2 is the sectional side view of the assembly comprising the rotation generation means in accordance with the present invention.
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Fig 3 is an exploded view of the section of the assembly as seen from A of Fig 2.
Fig 4A is a sectional side view of the rail assembly having a circular capsule contact lining in accordance with one embodiment of the present invention.
Fig 4B is a sectional side view of the rail assembly having a rectangular capsule contact lining in accordance with another embodiment of the present invention.
Fig 4C is a sectional side view of the rail assembly having a square capsule contact lining in accordance with yet another embodiment of the present invention
DISCLOSURE OF THE INVENTION:
The band sealing method as disclosed by the present invention involves the following sequence of operations.
Initially, hard gelatin capsules are aligned within cavities provided in multiples in a slat conveyor (1). The capsules are then passed through a sealing station, by driving the conveyor, with the capsules allowed to freely rotate within the said cavities.
Preferably, the sealing station is configured with one or more circular rotary disks mounted partially immersed in a gelatin container. The profile of the rotary disks along with its mechanism and is so designed

to pick up the required amount of gelatin solution from the said container and transfer it to the capsule surface.
A band of gelatin either in liquid or semisolid form is applied over the circumferential area of the joint portion of the cap and the body of the capsule. The application of the gelatin is such that uniform distribution of the applied gelatin is effected covering the- cap and the body portions around the cut line of the cap end in a uniform manner.
Preferably two sealing rollers are used to apply gelatin band around the capsule (not illustrated). The second sealing is effected to eliminate the unevenness and/or air bubble generation that might have occurred during the first sealing. The second band is applied while the first band is still in wet state.
Most preferably, a stronger sealing is formed by application of two thin bands over the cap and body portion around the cut end of the cap of the capsule.
From the sealing station, the capsules are then passed onto a cold wind zone (The setting zone).
Referring to Fig1 to Fig 3, in the setting zone, the capsules (2) are subjected to a blast of cold air which is blown directly from the bottom of the slat conveyor (1) and simultaneously in the same zone, the capsules (2) are axially rotated using a rotation generation means. The cold air is blown such that the air stream is directed substantially on the applied wet gelatin band around the capsules (2) in the rotating condition.

The apparatus for band sealing of hard capsules comprises a rotation generation means provided just above the surface of the conveyor, in the cold wind zone.
In one embodiment, the rotation generation means is an arrangement of one or more parallely aligned rails (3) whose longitudinal end comes into physical contact with the surface of the capsules (1) as the capsules (2) are freely held within the cavities (4) of the slat conveyor
(1)-
The contact of the longitudinal end of the rails (3) and the surface of the capsule (2) which is kept moving, result in substantially a number of axial rotations of the capsules (2), by 360 degrees or more within the cavities of the band conveyor. The speed and number of rotations may be c ontrolled t o s et t he a pplied w et g elatin uniformly a round t he cut end of the cap and body portion of the cap adjoining the cut end of the cap of the capsule.
Due to the foregoing arrangement of the rotations generation means in combination with the said band conveyor, the capsules (2) which are applied with a wet band of gelatin, are rotated and thereby simultaneously exposed uniformly to the blast of cold air.
Due to continuous rotation of the capsule (2), under cold air, the wet gelatin band is set uniformly.
In one embodiment, the rail (3) is lined with a capsule contact lining made of a material such as elastomer or rubber. The lining is

preferably in the form of a cord has a circular cross section as shown in Fig 4A.
In another embodiment, the capsule contact lining has a flat cross section as shown in Fig 4B.
In yet another embodiment, the capsule contact lining has a square cross section as shown in Fig 4c.
The capsules (2) are then passed on to a drying chamber where the band is completely dried under appropriate conditions. The uniform application and then uniform setting of gelatin band prevent the distortion of capsule during drying operation. The enclosed table 1 gives the data generated.
The capsules obtained by the above process, are free from any defects like bending or distortion.
Table 1: Bending measurement of various liquid filled band sealed capsule.
S. No. Trial No. Bending beyond 0.2 mm
1. Cold air and rotator Nil
2. No cold air, only rotator Nil
3. No cold air, No rotator 3nos.
4. cold air, No rotator 1no. Procedure
Capsules were filled with liquid and band sealed with gelatin solution with different parameters as shown in the table. 25 capsules were

taken at random and bending was measured using digital vernier caliper.
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Thus, while there have been shown and described and pointed out fundamental novel features of the present invention as applied to preferred embodiments thereof, it will be understood that various omissions and substitutions and changes in the form and details of the device described may be made by those skilled in the art without departing from the spirit of the present invention. For example, it is expressly intended that all combinations of those elements which perform substantially the same function in substantially the same way to achieve the same results are within the scope of the invention. Substitutions of elements from one described embodiment to another are also fully intended and contemplated. It is possible to introduce variations, in the whole or its parts, in the shape, materials and disposal, provided that said variations do not substantially alter the characteristics of the invention that are indicated by claims appended hereto.

WE CLAIM
1. An improved method for forming a band seal on a capsule, such
capsule having a body and a cap telescopically joined together,
comprising the steps of:
(i). applying gelatin in liquid or semisolid form substantially
over the circumferential area of the joint portion of the cap and the capsule, for forming a wet gelatin band thereon;
(ii). axially rotating the capsule after formation of wet gelatin band;and
(iii). blowing air at predetermined low temperature for setting whereby the gelatin band is uniform and free from distortion.
2. The method as claimed in claim 1, wherein the axial rotation of the capsules is carried out by 360 degrees or more.
3. An apparatus for forming a band seal on a capsule by the method as claimed in claim 1 comprising :
(i). atleast a pair of sealing rollers for applying gelatin band
substantially over the circumferential area of the joint portion of the cap and the capsule.
(ii). a rotation generation means for axially rotation the capsule subsequent to application of gelatin band; and

(iii). a cold air generating means to generate and blow air at predetermined low temperature over the capsule.
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4. The apparatus as claimed in claim 3, wherein the rotation generation means comprises one or more rails aligned substantially in parallel in contact with the surface of the capsules wherein the capsules are freely held within cavities of a slat converyor.
5. The apparatus as claimed in claim 3 or 4, wherein the rotation generation means rotates the capsule by about 360 or more degrees.
6. The apparatus as claimed in claim 4, wherein the rails have a capsu-le lining made of a material such as elastomer, rubber.
7. The apparatus as claimed in claim 6, wherein the lining is in the form of a cord having a circular cross section.
8. The apparatus as claimed in claim 4, wherein the lining is in the form of a cord having a flat cross section.
9. The apparatus as claimed in claim 4, wherein the lining is in the form of a cord having a square cross section.
Dated this 2nd day of December, 2002.
FOR SCITECH CENTRE By/their Agent

KRISHNA & ^AURASTRI