PACKAGING FOR PATCHES

Abstract: A package (12, 14) contains a transdermal patch (1) releasably mounted on a release liner (3) larger than the patch so that a peripheral edge (1a, 1b) of the patch is spaced from the edge of the release liner (3) by a border (7). The package (12, 14) is shaped and being sufficiently rigid that said edge of the patch is maintained spaced from the package. The package comprises a container (12) and a closure (14). The container has a recess containing the patch (1) and the release liner (3), and the recess has a base (18, 22) which includes a raised portion (18) located in the base so that, with the patch (1) facing the base, the edge (1a, 1b) of the patch is maintained spaced from the base in any position of the release liner within the recess.

Description: PACKAGING FOR PATCHES TECHNICAL FIELD The present invention relates to a package containing a patch for application to the skin, particularly but not exclusively a transdermal patch. The present invention also relates to a kit for making such a package and to the use of such a package. BACKGROUND OF THE INVENTION Medical transdermal patches have many uses, for example in hormone replacement, anti-anginal, travel sickness and smoking cessation therapy. Although various types of transdermal patches have been used, it is now generally preferred to use a patch which has a backing sheet and one or more layers, including an adhesive layer which attaches the patch to the skin. The adhesive layer is typically a viscous liquid containing at least one active component. The patch is supplied on a release-liner covering the adhesive, which is peeled off immediately before applying the patch to the skin. The active component then passes through the skin. It is known to package such patches in a polymer or multi-layer laminate envelope or sachet. WO 95/00122 (published 5 January 1995, after the priority date now claimed), shows an example of this, in which a release liner carrying four patches is enclosed in a resealable bag made of plastic film or foil laminate. A modified package is known from Japanese Utility Model publication 1-155428 (accepted publication no. 4-51782) in which the patch is mounted on a release liner provided with raised dimples to minimise contact between the envelope or sachet and the patch., A similar package has been marketed, for example, by Ortho-Cilag under the name Evorel . It has been found that although the raised dimples provide a limited degree of protection, they do not prevent pressure on the patch due to handling, leading to oozing of the viscous adhesive which forms a sticky ring around the patch. This results in a tendency for the patch to stick to the envelope or sachet. It is also known to provide a blister-pack in which a patch attached to a release liner, which is the same size as the patch itself, is located in a shallow blister formed between a plastic moulding and a foil lidding. A rib is formed around the blister, to increase rigidity of the otherwise fragile pack which is susceptible to curling. Such a patch is believed to TM have been marketed under the name TRIALSAT by Beta Pharmaceuticals. Use of a release liner which is the same size as the patch means that the only sticky part of the patch is at the periphery, though adhesive can ooze around the edges of the patch. However, because the patch and release liner are the same size, it can be difficult and messy to separate the two. It may be undesirable that the active component is touched by a user, except at the intended application point. Furthermore, the need for a reinforcing rib around the blister increases the overall size of the package, so that the package occupies a much larger volume than the patch itself. SUMMARY OF THE INVENTION The present invention seeks to overcome the above problems, by providing a novel package for a patch in which the patch is substantially prevented from sticking to the package. In addition the release liner can be more readily separable from the patch and the package may be rigid enough to provide a degree of mechanical protection for the patch without the overall size of the package necessarily becoming excessive in comparison to the size of the patch. Accordingly, the present invention provides a package containing a patch for application to the skin having an adhesive layer by which the patch is releasably mounted on a release liner larger than the patch, the peripheral edge of the patch being spaced from the peripheral edge of the release liner by a border region of the release liner, the package being sufficiently rigid and being shaped so that said peripheral edge of the patch is substantially prevented from contacting any part of the package. This prevents any adhesive which may emerge at the edge of the patch, during normal storage and transport of the package, from sticking the patch to the package. Desirably, the patch and release liner can move freely as a unit both in the lateral direction (i.e. in the plane of the patch) and in the vertical direction (i.e. perpendicular to the plane of the patch) within the package. The border region of the release liner preferably extends continuously around the patch, but the edge of the patch may coincide with the edge of the release liner at one or more zones, provided that the condition is met that the edge of the patch cannot contact the package. The present invention also provides a kit of parts for use in making such a package. Preferably the package comprises a container closed by a closure, the container having a central portion at a first depth from the closure joined to an outer portion at a second depth from the closure deeper than the first depth, the outer portion being provided with an outer wall to which the closure is attached. the dimensions being such that with the patch supported on the central portion with the release liner uppermost towards the closure, the edge of the patch lies above said deeper outer portion. In one preferred form, the patch is mounted on a release liner larger in area than the patch so that the periphery of the patch is spaced inwardly from the periphery of the release liner and the package comprises a container in the form of a moulded sheet and a closure sheet, the container having a flange region surrounding a recess containing the patch and release liner, the recess having a base which includes at least one raised portion located in the base so that, with the patch facing towards the base, the periphery of the patch is maintained spaced from the base in any position of the release liner within the recess, the closure sheet being secured to the flange region. Preferably the raised portion or portions are spaced from the periphery of the recess, and may take the form of a single raised central region smaller than the patch, or a plurality of raised regions, such as ribs, dispersed over a central area smaller than the patch. The invention is particularly suitable for a package containing a single patch, but may also for example be used for a package containing a plurality of patches mounted on a single release liner. DESCRIPTION OF SPECIFIC EMBODIMENT An embodiment of the invention will now be described by way of example with reference to the following drawings in which: Fig. 1 is a perspective view from underneath of a package containing a patch which is an embodiment of the invention; Fig. 2 is an underneath plan view of the package of Fig. 1; Fig. 3 is a partially cut-away top plan view of the package of Fig. 1; Fig. 4 is an exploded side view of the package of Fig. 1; and Fig. 5 is a section along X-X in Fig. 1. Referring to Figs. 1-3, a self-adhesive transdermal patch 1 consists of a backing and a thin adhesive layer (not separately shown) of viscous liquid containing an active component, such as a pharmaceutical, to be transported across the skin. This patch 1 is releasably mounted on a release liner 3 by the adhesive layer, with the adhesive layer interposed between the backing and the liner 3. The release liner 3, which may be e.g. a metallized plastics sheet, is larger than the patch 1 which is mounted on a central patch-carrying portion of one surface 6 of the release liner 3 surrounded all around by a border 7. The whole length of the peripheral edge of the patch 1 is inwardly spaced from the edge of the release liner 3. The border 7 is sufficiently wide to facilitate removal of the patch 1 from the release liner 3 by the user and to retain any adhesive escaping from under the patch on the surface 6 substantially to prevent adhesive reaching the edge of the release liner 3. The release liner 3 is divided into two parts about two-thirds along its length by a slit 9 across its entire width, the two parts being held together by the patch 1. To remove the patch 1 from the release liner 3, the patch 1 is folded back on itself at the slit 9 and a first (e.g. smaller) part of the release liner 3 may be removed. The thus exposed drug-in¬ adhesive layer of the patch 1 may be applied to the intended site of application on the skin and the second part of the release liner 3 removed, application of the patch 1 being completed by applying pressure to the backing of the patch 1. Thus, in this way, the patch 1 may be applied without any handling of the adhesive surface. In this specific embodiment, the patch 1 is substantially rectangular, with rounded corners, about 5cm wide by 6cm long and the border 7 is uniformly approximately 4mm wide all around the patch 1, with the slit in the release liner 3 about 22 mm from a short side. Of course a variety of shapes and sizes of patch 1 and release liner 3 may be used depending on the particular application. The patch 1 mounted on the release liner 3 is stored in a package 10 comprising a container 12 to which a closure 14 is adhesively sealed. In this embodiment the interior of the package 10 is hermetically sealed by the seal of the closure 14, and may be filled with an inert gas, such as nitrogen. The gas pressure helps to prevent the package 10 being compressed. The package 10 is sufficiently rigid to retain its shape and resist deformation under pressures and loads normally encountered in transport and storage. In this embodiment the container is made of transparent moulded plastics material sheet, and the closure 14 is flat, made from flexible metal (aluminium) foil, the package being constructed in the manner of a so-called blister pack with a recess containing the patch and release liner. As can best be seen from Figs. 4 and 5, the closure 14 and container 12 can be separated simply by peeling them apart, starting at a tab portion 16 where they are not sealed together. Other typical examples of alternative flexible materials which may provide a peelable closure are plastics sheet, or a laminate comprising aluminium and/or plastics material and/or paper, the closure in this case being flexible and sealed by a suitable adhesive or heat-sealable layer. However, as will be understood, a variety of materials may be used depending on the degree of rigidity or opacity required; for example the container 12 may be made of metal. Opacity may be desirable, to exclude light. The container 12 has a substantially flat horizontal central portion 18 typically occupying a major part of the area of the container 12. This is joined by a first wall 20 to a surrounding outer portion 22 of greater depth from the closure 14. The outer portion 22 is closed by an outer wall 24, the top of which joins a flange 26 to which the closure 14 is sealed. The tab portion 16 described above is at a part of the flange 26. In this embodiment, the top regions of the first, inner, wall 20, and the outer wall 24 are substantially vertical to provide clearly defined boundaries to the outer portion 22, whereas the bottoms of the first, inner, wall 20 and outer wall 24 curve smoothly to form the bottom 28 of the outer portion 22. With this construction, the outer portion 22 together with the inner and outer walls 20,24 serve to increase the overall rigidity of the package 10. Increased rigidity is provided by a shallow upstand 28a in the outer portion 22. When the package is in its normal rest position with the closure sheet 14 upwards, the centre of the patch 1 rests on the platform provided by the central portion 18, with the release liner 3 uppermost towards the closure 14. The border 7, described above, prevents the edge of the patch 1 itself contacting the outer wall 24. The central portion 18 is smaller than the patch 1 so that the whole length of the edge of the patch must lie above the trough formed by the outer portion 22. The depth of the central portion 18 from the closure 14 is greater than the combined thickness of the patch 1 and release liner 3 by an amount sufficient to allow the patch and liner to move freely between contact with the closure 14 and contact with the central portion 18, thus preventing the patch 1 being pinched or compressed between the closure 14 and the central portion 18 in normal conditions, thereby reducing the tendency for the adhesive to be squeezed out from under the patch 1. In particular, the package should withstand the weight of several (e.g. at least a dozen) such packages to enable stacking for transport. Typical pressures which the container should withstand without the patch being compressed are 100 grams spread over 1 square centimetre, and 200 grams spread over the entire patch. The depth of the outer portion 22 from the closure 14 is greater than that of the central portion 18 by an amount sufficient to prevent the edges la, lb of the patch 1, or adhesive escaping outwardly therefrom, contacting the bottom 28. In this embodiment, the central portion 18 is about 2.5mm deep from the closure 14 and the outer portion 22 is about 6.5mm deep from the closure 14 so the difference is about 4mm. If the release liner 3 and package 10 are sufficiently rigid, the difference in depths and/or the overall depth may be reduced without the edges la, lb of the patch contacting the bottom 28. As can be seen from the section shown in Fig. 5, the sum of the width a of the outer portion 22a at a first side and the width b of the central portion 18 is less than the sum of the width c of the border 7a of the release liner at the first side and the width d of the patch 1. Thus the edge lb of the patch 1, where adhesive may escape, is made to remain within the second outer portion 22b of the container, away from the inner wall portion 20b, by the edge of the first border portion 7a abutting the first outer wall portion 24a or by the edge of the opposite border portion 7b contacting the wall portion 24b. This is true for any cross-section, and for all locations and orientations to which the patch 1 can move within the package 10, so that no part of the peripheral edge of the patch 1 can contact the inner wall 20. In this embodiment, with a patch of the dimensions given above, the container 12 has a central portion 18 38mm wide, bordered by the outer portion 22 which is 13mm wide to give a total overall width of 64mm. The central portions 44mm long, bordered by outer portion 22 which is 15mm long to give an overall length of 74mm. The bottom 28 of the outer portion 22 curves smoothly into the inner wall 20 and outer wall 24 via arcuate sections respectively having radii of curvature of approximately 4mm. The same package 10 can accommodate alternative sizes and shapes of patches if desired, provided the edges of the patch are prevented from contacting the walls of the package as described above. As described above, the inner and outer walls 20,24 in this embodiment are smooth and continuous, and the boundaries of the outer portion 22 are clearly defined. However, as will be appreciated, the outer wall 24 (for example) may be interrupted by ribs or the like which obstruct movement of the release liner, the central portion 18 need not be flat, and the transition between the central portion 18 and the outer portion 22 need not be so abrupt. The central portion 18 may be a continuous upstanding rib or a plurality of upstanding areas. The important requirement in these embodiments is that the central portion supports the patch, preferably over a major part of the area of the patch, so that the edges of the patch cannot contact the central portion, or other parts of the container. The width a of the outer portion is then measured from a point (e.g. a rib) 24a (corresponding to the outer wall 24) which obstructs movement of the release liner 3 to the first point 20a where the depth is such that the central portion can contact the patch 1, and the effective width b of the central portion is measured therefrom to the furthest point 20b at which the depth is such that the central portion 18 can contact the patch 1. In all cases, the effective width b of the central portion 18 along any given section is less than the corresponding width d of the patch 1. Furthermore, if, as in the above described embodiment, the release liner 3 is not circular, the dimensions of the package 10 are usually chosen so that the release liner 3 cannot rotate within the package 10; the central portion 18 should be unable to contact the edges la, lb of the patch 1 in any location or orientation of the patch 1 possible within the package 10 . The invention is applicable to the packaging of medical, veterinary and non-medical and non-veterinary patches for application to human or animal skin.

Claims: CLAIMS 1. A package (12,14) containing a patch (1) for application to the skin, the patch having an adhesive layer by which the patch (1 ) is releasably mounted on a release liner (3 ) larger than the patch so that a peripheral edge (la, lb) of the patch is spaced from the edge of the release liner (3) by a border (7), the package (12,14) being shaped and being sufficiently rigid so that said edge of the patch is maintained spaced from the package. 2. A package according to claim 1 wherein the package comprises a container (12) and a closure (14), the container having a recess containing the patch ( 1 ) and the release liner (3), the recess having a base (18,22) which includes a raised portion (18) located in the base so that, with the patch (1) facing the base, the edge (la, lb) of the patch is maintained spaced from the base in any position of the release liner within the recess. 3. A package according to claim 2 wherein the container is in the form of a moulded sheet having a flange region (26) surrounding said recess, the closure being in the form of a sheet ( 14 ) and being secured to said flange region. 4. A package according to claim 2 or claim 3 wherein said raised portion (18) is central and is formed by at least one raised area at a first depth from the closure (14) surrounded by an outer portion (22) of said base at a second depth from the closure (14) deeper than the first depth, the outer portion (22) having an outer wall (24) joined to the closure, the dimensions being such that with the patch supported on said central raised portion (18) with the release liner (3) uppermost towards the closure (14), the edge (la, lb) of the patch lies above said deeper outer portion. 5. A package according to claim 4 wherein along any section from a first side of the package to a second side of the package, the section including respectively a first outer portion (22a), a central portion (18), and a second outer portion (22b) of said base of said container and respectively a first border portion (7a) , a portion carrying the patch ( 1 ) , and a second border portion (7b) of said release liner (3), the combined width of said first outer portion (22a) and said central portion (18) of the base is less than the combined width of the first border portion (7a) and the patch-carrying portion of the release liner (3) so that the edge (lb) of the patch adjacent said second border portion (7b) of said release liner overhangs the second outer portion (22b) of said base. 6. A package according to any one of the preceding claims wherein said adhesive layer includes a pharmaceutical or beneficial agent, and/or wherein said patch is a medicated transdermal patch. 7. A kit for making a package according to any one of the preceding claims comprising a container (12) having a recess whose base has a raised portion (18) and a closure (14) for sealing to the container (12) to retain the patch in the recess. 8. Use of a package according to any one of claims 1 to 6 for packaging a medicated transdermal patch.

Inventors: TRIGGER DAVID, TRIGGER, DAVID
Applicants: ETHICAL PHARMA LTD, TRIGGER DAVID, ETHICAL PHARMACEUTICALS LIMITED, TRIGGER, DAVID
Application year: 1995
Main classification: B65D75
IPC codes: A61J1, A61K9, B65D75