What is claimed is
1. A package comprising a product container including at least one recess for housing a product and a composite lid, said lid comprising an inner rupturable layer, an outer, non-rupturable protective layer and an intermediate adhesive layer joining said protective and rupturable layers, said protective layer being removable from said composite lid without causing the rupture of said rupturable layer, said lid being heat sealed to said container to form an air-tight compartment for said product.
2. The package of claim 1 wherein said rupturable layer is a metal foil.
3. The package of claim 2 wherein the surface of said metal foil layer which is joined to said container is coated with a heat sealable material.
4. The package of claim 1 which includes multiple recesses in said product container.
5. The package of claim 4 wherein the protective layer of said lid is divided into sections, each section covering an area approximately equal to the area defined by a recess in said product container whereby that portion of the protective layer covering a single recess may be removed without causing the removal of an adjacent portion of said protective layer.
This invention relates to a novel packaging system for solid materials in pill or tablet form. More particularly, the present invention relates to a novel package designed to securely hold pharmaceutical pills or other potentially dangerous products so as to reduce the possibility of obtaining accidental access to the contents of such a package.
Many commercially available packages for medicinal tablets and pills are formed from a flexible plastic container which houses the pill and a rupturable lid. In such arrangements, individual pills are removed from the package by pushing the pill through the rupturable layer by applying pressure to the flexible plastic container. Such an arrangement requires that the rupturable layer be fairly weak and brittle so that it may be easily ruptured when access to the package contents is desired. While such a packaging arrangement offers a substantial convenience to the consumer, the ease with which the package may be ruptured presents a substantial danger of accidental access to the package contents. Thus, a child gaining access to such a package could, quite easily, in the course of playing with the package, cause the lid to rupture and obtain access to a potentially dangerous drug.
Accordingly, it is an object of the present invention to provide a novel package construction which is not readily subject to accidental opening, particularly by children.
Yet another object of the invention is to provide a novel pill package which has a simple construction, is relatively inexpensive and permits the user to gain access to its contents in a simple fashion.
The above and other objects of the invention are achieved by a novel pill package which, in addition to the semi-rigid or flexible container and rupturable layer which have characterized prior art pill packages also includes a film layer adhesively joined to and in intimate contact with the rupturable layer. By employing a non-rupturable film layer and an adhesive which will permit stripping of that layer without rupture of the underlying rupturable layer, two steps in proper sequence are required in order to obtain access to the package contents. Thus, even if a child gains access to the package of the invention, the package cannot be accidentally ruptured and a deliberate peeling step followed by a rupture step will be required in order to obtain access to the package contents.
The invention will be further understood by reference to the drawings wherein:
FIG. 1 is a cross section of an individual package for containing a pill in accordance with the structure of the invention.
FIG. 2 is a perspective view of a package designed to contain multiple tablets which also illustrates the manner in which a single tablet is removed from the package.
Referring to FIG. 1, there is illustrated a package 10 for containing a single pill 16 which consists of a flexible plastic layer 12 having a depression or recess 14 which houses pill 16 and a composite lid 18 which forms an air-tight closure over the depression.
The flexible plastic layer 12 may be selected from a wide variety of semi-rigid or fully flexible materials and a variety of techniques which are well known in the art may be employed to form the recess in that layer. For example, the recess may be formed by a molding technique involving the application of heat and/or pressure to a plastic material such as polystyrene, polyethylene, polypropylene, polyvinyl chloride or a similar plastic material. The size and shape of the recess or cavity and the selection of a particular material is a matter of choice which will be dictated by the size and nature of the pill, as well as other considerations which are well known to those persons skilled in the art. The thickness of the plastic material used to form the recess is also not critical. The minimum thickness will be selected such that the recess will not be subject to accidental rupture. Suitable thickness will be in the range of 1 mil to 30 mils, preferably 5 to 15 mils, e.g. 10 mils.
The composite lid 18, which forms an air-tight closure with the pill container, comprises at least three and possibly four distinct layers which together reduce the possibility of accidentally obtaining access to the package contents. The three essential layers include a rupturable layer 20 which overlies and is in intimate contact with the peripheral shoulders 22 of product container 12; a peelable adhesive layer 24 which overlies and is in intimate contact with the rupturable layer 20; and a strippable film layer 26 overlying and in intimate contact with adhesive layer 24.
In a preferred embodiment, the rupturable layer is formed from a frangible material such as paper, selected plastics or metal foil. Since such materials are not readily heat sealable to the plastic container layer 12 to form an air-tight sealed package, it is necessary, with such materials, to provide a coating layer 28 of a heat sealable material on the surface of the rupturable layer which faces the plastic container. Such coatings are well known in the art and may be selected from such materials as vinyls, acrylics or polyolefins which are applied by spraying, dipping or similar techniques. In lieu of a rupturable metal foil, other rupturable materials such as cellophane, polyethylene, polypropylene and the like may be employed and in those instances where a heat sealable rupturable material is utilized, the heat seal coating 28 may be omitted. The thickness of the rupturable layer is not critical, and ordinarily will be maintained within a range which provides adequate protection for the package contents while still being capable of rupture without the application of undue force.
The nature of the added protective layer 26 is not critical and a wide variety of plastic or other materials may be employed. Among the materials which may be used are polyester, polyolefin, polyamide, polycarbonate and polysulfone films, or combinations thereof. Non-plastic protective layers such as paper or cardboard may also be employed and such materials offer the additional advantage of providing a suitable surface for printing instructions with respect to the use of the contents of the package. It will readily occur to those persons skilled in the art that a paper or carboard layer may be combined, if desired, with an underlying plastic film protective layer in order to provide a suitable printing surface. The thickness of the protective layer is not critical, although it should have sufficient thickness to avoid accidental rupture. Such thickness will vary with the selection of a particular material and can readily be determined by those persons skilled in the art. Typically, the protective layer may have a thickness in the range of 0.5 to 4 mils, preferably 0.5 to 1.5 mils, e.g., 0.75 mils.
The nature of the adhesive layer 24 which joins protective layer 26 to rupturable layer 20 is an important feature of the invention. While the exact nature of the adhesive employed will depend upon the materials used in forming the rupturable layer and the protective layer, the adhesive, in all cases, must be of such a nature that it permits the protective layer to be peeled away without causing rupture of the underlying rupturable layer. Accordingly, the adhesive employed must either have high adherence to the protective layer and relatively low adherence to the rupturable layer, or vice versa. Typical adhesives which exhibit this quality include rubber, vinyl, and acrylic cements. In a preferred embodiment where a metallic foil is employed as the rupturable layer and a polyester is employed as a protective layer, an adhesive comprising rubber or acrylic cement is suitable.
FIG. 2 illustrates a package structure including multiple recesses for housing multiple pills, or tablets and also illustrates the manner in which an individual pill may be dispensed. In this arrangement, a package 30 having multiple pill recesses 32 and 33 is formed from a single semi-rigid plastic layer 34 by conventional vacuum or thermo-forming techniques as previously described and a lid 36 of suitable size to cover all of the pill recesses is heat sealed over the entire container layer to form an air-tight package. By providing perforations or areas of weakness 38 completely surrounding each individual recess 32 in the multiple container structure the capability of removing a single pill at a time from the package is provided. Specifically, the perforations 38 serve to limit the amount of protective layer 40 which can be removed in a single stripping operation such that only the protective layer covering a single pill can be removed in a single stripping step. For example, as illustrated, if it is desired to remove a single pill 42 from recess 32, the stripping of protective layer 40 will be limited to the area defined by perforations 38a and 38b. Thereafter, only the portion of the rupturable layer 44 immediately above recess 32 will be ruptured by the application of pressure from the finger of the consumer on recess 32. By this technique, a series of individual pill containers substantially identical to that described in connection with FIG. 1 are created from larger integral layers of materials.
It will be readily understood by those persons skilled in the art that the package structure described herein may be used to package a wide variety of materials and is not limited to the packaging of any particular type of material. However, the package is particularly suited for housing dangerous drugs or other hazardous materials since the system requires two deliberate steps, in particular sequence, in order to achieve access to the package contents, thereby substantially reducing the possibility of accidental opening.
Having thus described the general nature as well as specific embodiments of the invention, the true scope will now be pointed out in the appended claims.