WO2010140169A2

WO2010140169A2 - Apparatus for pharmaceutical packaging

Info

Publication number: WO2010140169A2
Application number: PCT/IN2010/000366
Authority: WO
Inventors: Satish Gopal Rao; Atul Vilas Mane
Original assignee: Satish Gopal Rao; Atul Vilas Mane
Priority date: 2009-06-03
Filing date: 2010-06-03
Publication date: 2010-12-09
Also published as: WO2010140169A3

Abstract

An equipment and process for sealing a blister pack for packaging /encapsulating products are provided. The equipment uses a dot sealing method to seal a base sheet containing blisters to a lid sheet, and the equipment comprises sealing means consisting of a first knurling plate with a first set of knurls interspersed in accordance with a first pitch on an operative mating surface of said first knurling plate and a second knurling plate with a second set of knurls interspersed in accordance with a second pitch on an operative mating surface of said second knurling plate. The said knurls are adapted to create a bond between the base sheet and the lid sheet interposed in between the operative mating sides of said knurling plates by pressing the operative mating side of said first knurling plate on to said operative mating side of said second knurling plate.

Description

APPARATUS FOR PHARMACEUTICAL PACKAGING

Field of the Invention:

This invention relates to the field of pharmaceutical packaging.

Background of the Invention:

The expression 'product' used in this specification is deemed to include any product requiring packaging or specifically relates to pharmaceutical products which may be in the form of tablet, capsule, powder, pill, ampoules, syringes, or any product requiring protection from external environmental conditions or requiring to be stored under ambient conditions.

Pharmaceutical products, for retail sale are frequently packaged in "blister pack" packaging. A blister pack consists of a flat backing sheet called as "lid", generally of cardboard, plastic, thermoplastic, or metal foil; and a base having a formed plastic "bubble" or "blister", generally of transparent plastic, the backing sheet and blister being joined to form a sealed cavity in which the product rests.

Pharmaceutical blisters as packaging for pharmaceutical formulations serve to package tablets, capsules or other forms of pharmaceuticals; safely and protect them from external environmental influences which might in certain circumstances affect the pharmaceutical quality of the formulations. In this context, water or water vapour should be mentioned in particular. If water penetrates into the interior of a blister chamber it may cause lasting changes to the pharmaceutical quality of the drug stored therein. There is also the danger that volatile substances will diffuse out of the material contained in the blister during storage and thereby alter the pharmaceutical formulation. In addition, the blisters must be so designed that the atmospheric conditions inside them remain constant, e.g., in respect of inhalable preparations, so as not to alter their particle size distribution.

The method for packaging includes the steps, wherein:

- A base sheet, typically of aluminium or any such metal is taken;

- Blisters or recesses or protrusions are formed on each side of the joined region;

- A lid sheet, typically of aluminium or any such metal is taken;

- The lid sheet is bonded onto the base sheet by means of knurling plates, under pressure and / or heat, in order to form a thorough seal;

- Pre-defined sizes of packets are cut out for further packaging.

Typically, the, step of sealing is by means of knurling plates which may be male and female dies, and the act of knurling is performed by pressing the male and female dies together, with the sheets in between, and is temperature controlled i.e. at a temperature sufficient to soften the sheet and press them against each other to achieve sealing.

Due to overlapping of pressure points on knurling plates, the conventional dot sealing process caused dot piercing thus forming pin holes on the sealing surface and increased the possibility of moisture ingress in the blister chamber. ,

Traditionally, the sealing between the base sheet and the lid sheet was subjected to entry of moisture through capillary canals. These canals was as a result of the action of the knurling plate on the base sheet and lid sheet where sometimes pin holes occurred or micro-capillaries were formed between the impressions left by the sealing process.

Prior Art:

US Granted Patent No. 4,776,150 discloses an apparatus for sealing medication blister cards including a unit dose of medication in at least one, if not all, of the blisters comprising card. The apparatus for sealing medication blister cards includes a card holder for receiving the filled medication card and a heated sealing head movable into juxtaposition with a top surface of the filled card so as to apply both heat and pressure to the card as it is held between the card holder and the heated sealing head. The card holder includes first and second ridges. The heated sealing head includes a contacting surface that is in contact with the top surface of the filled card, wherein the contacting surface is knurled and the knurled surface is adapted to contact the medication blister card. The knurled surface is defined by a plurality of grooves, each one of said grooves intersecting at least one of the grooves. More specifically, the blister card is effectively sandwiched between the knurled surface of the sealing head means and the first and second ridges of the card-holder means.

US Granted Patent No. 4617781 discloses a polypropylene wrap end seals and process for making same. More specifically, disclosed is a process for sealing ends of voided polypropylene film tampon wrap by mechanical crimping. Each end of the voided polypropylene film wrap in is sealed by a pair of horizontal teeth knurled wheels each wheel having a pitch of 50 teeth per inch, one of which is heated to a temperature of 125 DEG.+-.15 DEG Fahrenheit, with the sealing force applied to seal each end of the voided polypropylene film wrap by the pair of knurled wheels being approximately between 800 to 4050 lbs/inch of the knurl width.

In case of the apparatus for sealing planar sheets together as disclosed in the '781 US Granted Patent the pair of horizontal teeth knurled wheels is used and each wheel is having a pitch of 50 teeth per inch (i.e. same pitch). Further, the apparatus for sealing planar sheets together as disclosed in the '781 US Granted Patent is not used for manufacturing an air-tight sealed blister packages.

US Granted Patent No. 7017324 discloses a machine used for automatic packaging of or hermetically sealing products, in particular tablets, pills, capsules and the like. The machine includes welding rolls provided with a plurality of radial recesses, regularly spaced apart axially and angularly, which face corresponding radial recesses of the adjacent welding roll during the synchronous movement of the welding rolls to form a series of cavities that are adapted to hold the products. The outer surface of the welding rolls is suitable knurled to create knurled impression along peripheral edges of the cavities and to form hermetic sealed pockets. Further, peripheral edges provided at the recesses of each welding roll are heated by a group of electric heating elements suitably distributed on the welding roll. The machine further includes a cutting means, which pre-cuts the continuous strip between adjacent transversal rows of welded pockets.

US Granted Patent No. 3759011 discloses a packaging machine for packaging of articles of uniform size, such as pharmaceutical tablets. The blister packages formed in accordance to method and machine disclosed in the 'Oi l US Granted Patent involves passing a pair of webs of indefinite length of usually transparent, thin material between a pair of laminating rolls. The laminating rolls contain die cavities which come into register as they pass through the nip of the laminating rolls, and an article feed is directed to the nip of the rolls to feed articles by gravity one at a time in synchronism with the closing of the die cavities, such that, as the die cavities pass through the nip, the two webs of material have the article positioned between them. In this type of machine the two webs of material are caused to adhere, for example by application of heat where a thermoplastic material is used, at the location of the nip of the rolls by heating one or both of the rolls, wherein one of the rolls is knurled. More specifically, the web with the pocket containing the tablet or other article is immediately positioned against the other web at the nip of the laminating rolls and the two webs are caused to adhere by pressure and heat. The surface of roll is knurled in order to improve the appearance of the product by eliminating wrinkles in foil. In case of the apparatus for packaging or hermetically sealing articles as disclosed in the 'Oi l US Granted Patent, the surface of only one roll is knurled in order to eliminate wrinkles in foil.

US Granted . Patent No. 4790118 discloses a machine for packaging medications in unit dosage form and labeling them specific to the patient. The method for packaging medications in unit dosage form includes two strips of packaging material that are merged and sealed by a pull and seal assembly which is mounted to the front housing wall and that includes a pair of beatable cylindrical roller platens, which bring the two strips of packaging material together and seal them around a medication unit. The cylindrical roller platens are very similar in some respects, each of them being comprised of three arcuate sectors bolted together onto the drive tube. The platens .are heatable. There are three equally spaced anvil pieces in the platen assembly. Similarly, there are three equally spaced serrating blades in the serrating platen assembly. The peripheral surfaces of the three sectors in each of the two platens are lightly knurled. There are sector at the top in the platen assembly and the location of the adjacent sector. The counterpart knurled cylindrical surface portions of the platen assemblies are urged into engagement with each other by the Belville spring stacks. Drive for the tubes is provided so that the platens move in synchronism and the blades of platen engage the anvils of platen for serrating the packaging strips after sealing.

In each of the above mentioned patents, control relating to ingress of moistur.e is not absolute under certain conditions of pressure. There is therefore a need to improve the blister packaging by reducing the the occurrence of microchannels and pin holes between the sealed surfaces / sheets to obtain less ingress of moisture into the blister chamber. Also, the lid sheet is coarse in its appearance and texture. Thus, the printed matter, if any, on the lid sheet, becomes illegible. In many cases of prior art, the sealing is sensitive to alignment of the sealing plates in order to achieve a complementary mesh. There is a need to eliminate this need of alignment, thus increasing the output rate of sealing.

Objects of the Invention:

An object of the invention is to provide an improved packaging for tablets and capsules, with increased adhesion between substrates used for forming the package. Another object of the invention is to have enhanced barrier protection i.e. to hinder the entrance of moisture, through the sealing bond into the blister chamber.

Yet another object of the invention is to provide a packaging process wherein the package is insensitive to misalignment of the top and bottom sealing plates (used for the sealing process).

Still another object of the invention is to provide a packaging process which can be used to form a package, said packaging process allowing for sealing the packages at lower temperatures.

An additional embodiment of this invention is to provide a packaging process which results in elimination of capillary formation in the formed package and also in reduction of pin holes in lid sheet which is observed in traditional top sealing plates.

Yet an additional embodiment of this invention is to provide an aesthetically better pharmaceutical package.

Still an additional embodiment of this invention is to provide improved readability of printed matter on the reverse side of the pharmaceutical package.

Summary of the Invention: According to this invention, there is provided an equipment for sealing a blister pack for packaging / encapsulating products, using a dot sealing method for sealing a base sheet containing blisters to a lid sheet, said equipment comprises sealing means consisting of a first knurling plate with a first set of knurls interspersed in accordance with a first pitch on an operative mating surface of said first knurling plate and a second knurling plate with a second set of knurls interspersed in accordance with a second pitch on an operative mating surface of said second knurling plate, said knurls being adapted to create a bond between a base packaging sheet and a lid sheet interposed in between said operative mating sides of said knurling plates to create a fine pattern of sealing points (dots) on said lid sheet, with a reduced pitch there between, by pressing said operative mating side of said first knurling plate on to said operative mating side on said second knurling plate.

Typically, said first knurling plate includes grooves adapted to receive said blisters of said base sheet.

Typically, said pitch of said first knurling plate is in the range of about 0.5mm to about 1.0mm.

Typically, said pitch of said first knurling plate, particularly is 0.8mm

Typically, said pitch of said second knurling plate is in the range of about 0.5mm to about 1.0mm.

Typically, said pitch of said second knurling plate, particularly is o.6mm. Typically, said first knurling plate is a metal plate.

Typically, said second knurling plate is a metal plate.

According to this invention, there is provided a process for sealing a blister pack for packaging / encapsulating products, using a dot sealing method for sealing a base sheet containing blisters to a lid sheet, said process comprise the steps of:

- placing a base sheet with blisters onto a first knurling plate with said first set of knurls interspersed in accordance with a first pitch on an operative inner side of said first knurling plate;

- placing a lid sheet onto a second knurling plate with a second set of knurls interspersed in accordance with a second pitch on an operative inner side of said second knurling plate; and

- pressing said base sheet and said lid sheet against each other between said first knurling plate and said second knurling plate to create a bond between said base sheet and said lid sheet with a fine, reduced-pitch pattern of dot bonding to reduce ingress of moisture from periphery of said sheets to said blisters.

Typically, said step of placing a base sheet with blisters onto said first knurling plate includes the step of positioning said blisters within predefined grooves of said first knurling plate.

Typically, sealing temperature for effective sealing is in the range of 140 degree centigrade to 210 degree centigrade. Brief Description of the Accompanying Drawings:

The invention will now be disclosed in relation to the accompanying drawings, in which:

Figure 1 illustrates a schematic of the process used for pharmaceutical packaging;

Figure 2a illustrates a view of the lid sheet of the pharmaceutical package in accordance with the prior art; and

Figure 2b illustrates a view of the lid sheet of the pharmaceutical package in accordance with this invention.

Detailed Description of the Accompanying Drawings:

According to this invention, there is provided a process for packaging and forming a pack for encapsulating capsules and tablets.

In accordance with an embodiment of this invention, there is provided a system and method for improved packaging, especially in pharmaceutical industries.

In accordance with an embodiment of this invention, there is provided a step of forming effected by a forming means (F) adapted to formulate sheets of metal / thermoplastics from rolls in accordance with pre-defined thickness or patterns for forming a base sheet and a lid sheet. Typically, said base sheet, and said lid sheet may have different characteristics. The process of forming also includes the step of provisioning sockets or holes on the base plate to accommodate the tablets or capsules for encapsulation.

In accordance with another embodiment of this invention, there is provided a step of sealing effected by a sealing means (S). Sealing is effectively actuated by a process called knurling which is performed by knurling means (KnP) or by knurling plates. Typically, this act of knurling, seals the lid sheet to the formed base sheet. Typically, the sealing method used is dot sealing. According to one embodiment of this invention, there is provided a first set of knurls on a first knurling plate, said first set of knurls disposed uniformly across an operative side of the first knurling plate, said knurls interspersed in confirmation with a first pitch. According to another embodiment of this invention, there is provided a second set of knurls on a second knurling plate, said second set of knurls disposed uniformly across an operative side of the second knurling plate, said knurls interspersed in confirmation with a second pitch. The operative side of the first knurling plate faces the operative side of the second knurling plate. Typically, said first set of knurls and said second set of knurls are disposed such that when the two knurling plates engage with each other, with sheets in between, the knurls act onto the sheets on either side to create an adhesion between the sheets. The disposition of the knurls, in accordance with this invention is such that, a criss-cross pattern of dots (sealing points) (as seen in Figure 2b), effected by the knurls is obtained, on the sheet. This pattern eliminates entry of moisture, and creates barrier in its path, thus obfuscating the ingress of moisture from the edges of a pack to the locations where capsules or tablets are kept. The knurls of the knurling plates provide the dotted embedding to press the lid sheet against the base sheet at pre-defined intervals, specifically by creating an adhesion at the dots due to compression. By reducing the pitch on the knurling plates, and using a pair of knurling plates with different pitches relative to one another, the dots are formed relatively close to each other. The pattern is as shown in the accompanying drawings (Figure 2b) and also, the coarseness is reduced, thus forming a fine surface at the lid sheet. Thus, sealing that is achieved consists of a combination of sealing points arranged in arrays having different pitches, thereby increasing the density of the sealing points.

Typically, the mating surface of lid sheet is provided with an adhesive layer.

In accordance with yet another embodiment of this invention, there is provided a step of punching effected by a punching means (P) adapted to punch out pre-defined measurements of the formed and knurled package to provide a specific number of products per package.

Thus, in accordance with the embodiments of the invention, and the improved process used, the formed package is envisaged to have a relatively fine surface of the lid sheet when it is fitted onto the base sheet. The coarseness (as seen in Figure 2a) is replaced by a finer texture (as seen in Figure 2b).

The technical advancement of this invention relates to the step of knurling, in that, the. knurling plates having a first set of knurls having a first pitch, and a second set of knurls having a second pitch (different from the first pitch), are envisaged, thus facilitating the formation of an improved packaging. By means of using this assembly of knurling plates with different pitches, the sealing assembly becomes insensitive to alignment (which was required by the prior art).

The technical advancement lies in:

1) providing an alignment free sealing stage, for forming a package for pharmaceutical packaging;

2) eliminating capillary formation and pin holes within the sealed package for ingression of moisture;

3) providing a fine texture on the exposed surface of the lid sheet which increases resolution of printed matter from its surface;

4) achieving the package formation by means of sealing, at lower temperatures.

The invention will now be determined in relation to its characteristics by means of tests performed vis-a-vis the prior art. Same material (Aluminium Alloys or SS304) were used in preparing the package by the process of the prior art as well in preparing the package by the process of this invention. In the prior art the sealing plates used contained knurls with the same pitch. In the art of the current invention, a first sealing plate with a set of knurls having a first pitch, and a second sealing plate with a set of knurl having a second pitch (different from a first pitch) was used. Sealing temperatures were observed at both instances. In the first instance, where sealing plates were same (in accordance with the prior art), the sealing occurs at temperatures ranging from 180 Deg. C to 220 Deg. C were recorded for effective sealing. In the second instance, where sealing plates were different (in accordance with this invention), temperatures ranging from 140 Deg. C to 210 Deg. C were recorded for effective sealing. Thus, the reduction in temperature is achieved, by means of the system of this invention. Further, it was found that, by using the system of the prior art, leakage was observed beyond 300 mm of Hg, after withstanding the pressure for 1 minute. By using the system of the current art, no leakage was observed even at 500 mm of Hg, after withstanding the pressure for 2 minutes. It was also observed that alignment of the two plates was necessary to achieve the package through the system of the prior art, and no alignment of the two plates was necessary to achieve the package through the system of the current art. Tests relating to Water Vapour Transmission Rates were conducted on both packages. The parameters of the test were temperatures of 27 +/- I⁰C and at Relative humidity of 65 +/= 2%. In the sealing pattern of the prior art, 0.0006 gms increase/Blister was observed, while in the sealing pattern of the current art, 0.0004 gms increase/Blister was observed. Thus, ingression of moisture was curbed.

While considerable emphasis has been placed herein on the particular features of this invention, it will be appreciated that various modifications can be made, and that many changes can be made in the preferred embodiments without departing from the principles of the invention. These and other modifications in the nature of the invention or the preferred embodiments will be apparent to those skilled in the art from the disclosure herein, - whereby it is to be distinctly understood that the foregoing descriptive matter is to be interpreted merely as illustrative of the invention and not as a limitation.

Claims

Claims:

1. An equipment for sealing a blister pack for packaging / encapsulating products, using a dot sealing method for sealing a base sheet containing blisters to a lid sheet, said equipment comprising sealing means consisting of a first knurling plate with a first set of knurls interspersed in accordance with a first pitch on an operative mating surface of said first knurling plate and a second knurling plate with a second set of knurls interspersed in accordance with a second pitch on an operative mating surface of .said second knurling plate, said knurls being adapted to create a bond between a base packaging sheet and a lid sheet interposed in between said operative mating sides of said knurling plates to create a fine pattern of sealing points (dots) on said lid sheet, with a reduced pitch there between, by pressing said operative mating side of said first knurling plate on to said operative mating side on said second knurling plate.

2. An equipment as claimed in claim 1 wherein, said first knurling plate includes grooves adapted to receive said blisters of said base sheet.

3. An equipment as claimed in claim 1 wherein, said pitch of said first knurling plate is in the range of about 0.5mm to about 1.0mm.

4. An equipment as claimed in claim 1 wherein, said pitch of said first knurling plate, particularly is 0.8mm.

5. An equipment as claimed in claim 1 wherein, said pitch of said second knurling plate is in the range of 0.5mm to about 1.0mm..

6. An equipment as claimed in claim 1 wherein, said pitch of said second knurling plate, particularly is 0.6mm.

7. An equipment as claimed in claim 1 wherein, said first knurling plate is a metal plate.

8. An equipment as claimed in claim 1 wherein, said second knurling plate is a metal plate.

9. A process for sealing a blister pack for packaging / encapsulating products, using a dot sealing method for sealing a base sheet containing blisters to a lid sheet, said process comprising the steps of:

10. A process as claimed in claim 9 wherein, said step of placing a base sheet with blisters onto said first knurling plate includes the step of positioning said blisters within pre-defined grooves of said first knurling plate.

l l .A process as claimed in claim 9 wherein, sealing temperature for effective sealing is in the range of 140 degree centigrade to 210 degree centigrade.