Patent Publication Number: US-5894930-A

Title: Directional push and peel easy to open child resistant blister package

Description:
This application claims the benefit of U.S. Provisional Application No. 60/027,305, filed Oct. 10, 1996. 
    
    
     FIELD OF THE INVENTION 
     The present invention relates to a blister card package for the packaging and delivery of solid medicaments such as tablets or capsules that is both child resistant and easy to use by adults and seniors. 
     BACKGROUND OF THE INVENTION 
     Blister card packages are one form of container commonly used for the packaging of medicaments, particularly for unit-dose packaging where the delivery of individually packaged dosage units to the consumer or patient is desirable. A suitable blister card package provides a container for the delivery of solid medicaments that is tamperproof, airtight, uses conventional materials and equipment to produce and is thus economical. 
     Generally, a conventional blister card package provides a container for individual dosages of the medicament separately packaged for delivery of the individual dosage to a patient. Typically, a blister card package contains a number (usually about 6-8) of individual dosages on a card where each dosage is separately contained and can be separated by perforations such that it can be readily detached. The blister card package is usually constructed of several layers. The top layer is a container sheet or container formstock constructed of a rigid material having integrally formed cavities or wells designed to hold the dosage form. The container sheet is sealed to a closure sheet (or lidstock) generally constructed of a foil and paper laminate. The blister package can be designed for removal of the dosage form from the container in a variety of ways. In some packages, the dosage is removed by pressing it through the closure sheet, where the closure sheet is made from a rupturable material. In other designs, the closure sheet is designed to be peeled off from the container sheet to remove the dosage form. Alternatively, the blister is scored to form a weakened area enabling the user to tear the blister and expose the cavity containing the tablet. 
     In designing a suitable blister card package, it is desirable that the package be tamper resistant and airtight but be easily opened by adults. At the same time, it is often desirable that the package be child-resistant and not easily opened by children. A problem with many conventional blister packages is that they are difficult to open, particularly by seniors or others with impaired dexterity but even by a healthy adult. In a rupturable package, the tablet or capsule may be damaged during opening. In a peel-apart package, the layers can be difficult to manipulate and separate because the layers are thin and tightly sealed. Thus, there is a need for a blister card package design which allows easy access by adults, including seniors, yet passes child resistant testing. There is also a need for a blister card package which meets these requirements and which utilizes conventional materials and can be manufactured using conventional equipment. U.S. Pat. No. 4,294,361 discloses a blister strip package having two cavities; a first cavity for containing the dosage form, and a second cavity laterally aligned with the first cavity which is covered by an unsealed area in the closure sheet having scored lines for disruption of the closure sheet. In operation, the second cavity is completely inverted to bear upon the covering sheet to disrupt it at the scored lines forming a pull tab to peel the closure sheet from the container sheet. 
     SUMMARY OF THE INVENTION 
     The invention is a child resistant and easy to use blister package for containing a solid medicament that utilizes a push and peel mechanism as an opening feature. The multi-section blister card package comprises a rigid container sheet with cavities for containing the product such as a solid dosage form medicament, and a backing closure sheet sealed to the container sheet and covering the product cavities. The opening feature is accomplished using a preformed second cavity in the blister container sheet which is adjacent to the cavity containing the product and a corresponding full score or cut in both the backing closure sheet and the container sheet. A land area or notch of material that is not cut through is maintained in the score area to add break away resistance for hindering child access. An unsealed area in the closure sheet encompasses the preformed second cavity and score area allowing for easy separation of materials. The blister is opened by pushing on the pre-formed cavity and score area to easily break the land area and free the backing closure sheet at the score forming a pull allowing for easy access to separate and pull the backing material towards the product cavity and thus exposing the product cavity. 
     The pre-formed second cavity is preferably configured differently from the product cavity so as not to be mistaken as a product cavity. The blister card package is multi-sectional having perforations between the product cavities which permits separation of one product unit at a time. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     The invention described herein will be better understood from the attached drawings which include: 
     FIG. 1 is a top plan view of a typical embodiment of a blister package of the present invention; 
     FIG. 2 is a cross sectional view of a blister package of the present invention. 
    
    
     DETAILED DESCRIPTION 
     The invention described herein can be seen in FIGS. 1 and 2. There is contained a blister package 10 separated into individual dosage sections 11 which are separable from the remainder of the package 10 via score lines or perforations. Each individual section is provided with a raised product cavity 13 to accommodate a product such as a tablet, capsule or the like. As shown in FIG. 1, in this package 10 there are typically six sections on the blister pack, although other alternate configurations are possible. For example, a blister card may be configured to contain eight or twelve sections. Each of the sections may be detached from the blister package 10 by bending and tearing along the lines of perforations, as known in the art. 
     The blister package 10 has at least two layers as shown in FIG. 2. The first layer is a container sheet 14 made of a rigid, heat sealable material from which the product cavities 13 may be formed. The second layer is a closure sheet 15 which is heat sealed to the container sheet as indicated in FIG.2. The closure sheet 15 completely overlays the cavity bearing container sheet 14 and is heat sealed or glued to the container sheet 14 to provide an airtight seal. Both the container sheet layer 14 and the closure sheet layer 15 are formed from conventional materials. 
     The container sheet 14 is preferably formed of a strong, rigid polymeric material, such as transparent polyvinyl chloride, polyvinyl dichloride, polyethylene or polypropylene. The container sheet has a substantial thickness of up to about 25 mils, more preferably about 10 mils, to provide the needed rigidity and to protect the contents of the blisters form damage during shipping. The container sheet should have the required strength to prevent access by a child. The product cavities 13 are integrally formed in the container sheet and have the desired configuration to contain the product. 
     The closure sheet 15 is preferably a laminate of thin metal foil such as aluminum foil and paper. The foil side of the laminate faces the product contained in the cavity and the paper side provides the bottom layer of the blister card package. The paper layer typically serves as the label for the blister card package. 
     The container sheet 14 a nd the closure sheet 15 are typically sealed together by means of heat sealing or adhesives an known in the art. 
     Adjacent to, and laterally aligned with the product cavity 13 of the container sheet 14 is a corresponding unsealed area 16 in the closure sheet 15. Underlying the unsealed area is a second raised cavity 17 in the container sheet 14. The second raised cavity 17 and the corresponding closure sheet 15 in the unsealed area 16 have a score or cut 18 which runs completely through the container sheet and the closure sheet. A land area or notch 18 of material that is not cut through is maintained in the score area to add break away resistance for hindering child access. The blister is opened by pushing on the second raised cavity 17 at the score area to easily break the land area 18 and free the backing closure sheet at the a score area. The pre-formed second cavity 17 and unsealed area 16 assist in forming a pull tab by providing an unsealed area where the container sheet 14 and closure sheet 15 have a visible spatial separation, allowing one to easily separate and pull the closure sheet 15 towards the product cavity 13 and exposing the product for removal from the blister package. 
     In the preferred embodiment shown, the unsealed area 16 and the corresponding raised second cavity 17 have a &#34;D&#34; configuration which is large enough to accommodate a thumb used to apply pressure on the upper surface of the raised second cavity 17 at the score line 18. This exposes a pull tab formed by the unsealed area which can be used to peel back the closure sheet from the container sheet to expose the product cavity 13. 
     Child resistance is provided by the present invention since one must obviously understand the procedure required to apply pressure at the score line to form the pull tab for peeling back the closure sheet.