Patent Publication Number: US-2012024724-A1

Title: Medicine Disposal Container

Description:
PRIORITY 
     This application claims the benefit of priority to European Patent Application No. 10171648.8, filed Aug. 2, 2010, the entire contents of which are hereby incorporated by reference herein. 
     FIELD OF THE INVENTION 
     Embodiments of the present invention relate to a container for disposing of medicines. In particular, although not exclusively, embodiments of the invention relate to a container for capturing and disposing of liquid medicines dispensed in the form of a spray. 
     BACKGROUND 
     The safe use of medicines applies not only to their administration to patients but also to their disposal. Safe disposal of medicines is important in order to avoid unwanted exposure to drug compounds with potentially hazardous, even fatal, effects. Although such unintended exposure could be harmful to the patient, it is of particular concern if it is to individuals who are not receiving the medication, including family members or other household contacts, and especially children, and carers and pets. 
     Some liquid medicines, by which we mean a liquid in which the drug substance is dissolved or suspended, are dispensed in the form of a spray, for example for administration into the oral cavity, nose, lungs, skin or eye. 
     Dosage forms using metered dose sprays, such as nasal sprays, present a particular disposal challenge. Referring to  FIG. 1 , a typical nasal spray  100  comprises a bottle  110 , which holds liquid medication  120 , to which is attached a metered-dose spray pump  130 . The example spray  100  shown in  FIG. 1  comprises a nozzle  140  for insertion into a nasal passage of a patient, although it will be realised that other nozzle configurations may be utilised. In response to actuation of the pump  130 , liquid  120  is drawn into the pump  130  via a dip tube  150  which extends downward into the medication  120 . In order for the pump  130  to function correctly it has to be used in a substantially upright orientation, by which we mean that the dosing nozzle  140  is at an angle which does not exceed approximately 45° from vertically upward. 
     Before the spray  100  is used to administer a dose, it needs to be “primed”. In the priming process the dispensing mechanism of the pump  130  is actuated to draw liquid into the dip tube  150  and the pump  130 . As illustrated in  FIG. 2 , the pump  130  may be primed by a force  210  applied between the bottle  110  and the pump  130 . Actuating the pump draws  220  liquid from the bottle  110  up the dip tube  150  and fine droplets of the liquid are expelled  230  from the nozzle  140  as a spray. A number of actuations i.e. presses of the pump  130  may be required in order to displace all of the air in the dip tube  150  and pump  130  and to replace it with liquid  120 . When primed, the spray  100  dispenses a full dose of the medication  120  to the patient. 
     In the process of priming the spray  100 , some droplets  230  comprising liquid  120  are emitted from the spray  100  into the atmosphere. If the drug compound in question is hazardous, it is desirable to capture the liquid  230  emitted from the spray  100  during priming. Similarly, if medication  120  remains in the bottle  110  at the end of use, it may need to be emptied which may require further actuations of the spray  100 . 
     To capture the drug droplets  230  which require disposal, it is possible to use an absorbent paper material such as a tissue. However, the individual may be exposed through skin contact to the liquid  120  containing the drug when holding the paper material. Furthermore, the discarded tissue or paper itself represents a hazard, if accidentally ingested for example. 
     This invention aims to solve the problems associated with the safe capture and disposal of unwanted liquid medications, particularly medications administered from sprays. 
     It is an object of embodiments of the invention to at least mitigate one or more of the problems of the prior art. 
     SUMMARY OF THE INVENTION 
     According to a first aspect of the invention there is provided a container for liquid medicine disposal having one or more interior surfaces associated with activated carbon for capturing a drug dissolved in the liquid medicine. The invention may also be useful for capturing drug in the form of a liquid suspension, in particular in the scenario where an attempt is made to recover the drug from the container by adding a solvent for the drug. In such a scenario, when the solvent is added, the drug will dissolve and may then adsorb to the activated carbon thus rendering it unrecoverable. 
     According to a second aspect of the invention there is provided a method of making a container for disposing of liquid medicine, comprising associating activated carbon with one or more interior surfaces of the container for capturing a drug within the liquid medicine. 
     According to a further aspect of the invention there is provided a container for liquid medicine disposal, characterised by the container having one or more interior surfaces associated with an activated carbon cloth for capturing a drug dissolved in the liquid medicine and an absorbent material for absorbing a liquid component of the medicine. 
     According to a further aspect of the invention there is provided a method of making a container for disposing of liquid medicine, characterised by comprising: associating an activated carbon cloth with one or more interior surfaces of a container for capturing a drug within the liquid medicine. 
     According to a further aspect of the invention there is provided a method of disposing of a liquid medicine, comprising placing the liquid medicine in a container having one or more interior surfaces associated with activated carbon cloth, such that the activated carbon cloth at least partly adsorbs a drug present in the medicine. Optionally, the method comprises substantially sealing the container. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       Embodiments of the invention will now be described by way of example only, with reference to the accompanying figures, in which: 
         FIG. 1  shows an example of a spray for use with embodiments of the invention; 
         FIG. 2  illustrates the operation of the spray; 
         FIG. 3  shows a first embodiment of the invention; 
         FIG. 4  shows a second embodiment of the invention; 
         FIG. 5  shows three embodiments of the invention; 
         FIG. 6  illustrates a method of manufacturing an embodiment of the invention; 
         FIG. 7  illustrates an embodiment of the invention; 
         FIG. 8  illustrates another embodiment of the invention; and 
         FIG. 9  illustrates a further embodiment of the invention. 
     
    
    
     DETAILED DESCRIPTION OF EMBODIMENTS OF THE INVENTION 
     Embodiments of the present invention provide a drug capture device in the form of a container having one or more interior walls which are associated with activated carbon cloth to adsorb drugs. In some embodiments, the container may further comprise a material to absorb a liquid in which the drug is dissolved or suspended. 
     A container  300  according to a first embodiment of the invention is shown in  FIG. 3 . In the first embodiment of the invention, the container  300  is in the form of a pouch  300 , which is illustrated particularly in  FIG. 3(   a ). 
     In some embodiments, the pouch  300  comprises first  310  and second  320  substantially planar sheets forming a front and back of the pouch  300 , respectively. The front and back sheets  310 ,  320  may be bonded together around three peripheral edges, i.e. along bottom and opposing side edges of the pouch  300 . The bonding may be achieved using adhesive or by heating the sheets  310 ,  320 .  FIG. 3(   b ) shows a cross section through the pouch  300  when formed by affixing peripheral edges of the sheets  310 ,  320 . Alternatively, as shown in  FIG. 3(   c ), concertinaed side portions  330  may interpose the first and second sheets  310 ,  320  at opposing sides of the pouch  300  to separate and allow relative movement of the sheets  310 ,  320  toward and away from each other. It will be realised that other constructions of the pouch  300  may be envisaged, such as the pouch  300  being formed by a single sheet of material folded over and bonded along a side and a bottom edge. 
     A top edge of the pouch is left open, i.e. the sheets  310 ,  320  are separate to form an opening  325  into the pouch  300  to allow the nozzle  140  of the spray  100  to be inserted into the pouch  300  during priming of the pump  130 . 
     In some embodiments, the second sheet  320  forming the back of the pouch  300  may include a flap portion  340  which extends upward beyond the upper edge of the first sheet  310 . The flap portion  340  may be formed from the second sheet  320  and be divided there-from by a fold, indicated with a dotted line in  FIG. 3 , which encourages folding of the flap portion  340  along the upper edge of the pouch  300  over the first sheet  310  so as to substantially seal the pouch  300 . An interior face of the flap portion  340 , i.e. facing the first sheet  310  when folded over, may include an adhesive layer for sealing the flap portion  340  to an outer surface of the first sheet  310  when folded over. To prevent accidental attachment of the flap portion  340  to the front sheet, a strip of material may be removeably attached to the adhesive layer for removal before sealing the pouch  300 . A double-sided tape with a peel-off paper on the outer surface, also known as a finger-lift tape, is an example of a means for adhesion of the flap portion to the front sheet. As will be appreciated, when formed from planar sheets of material, the pouch  300  is substantially flat which aids packing of a plurality of pouches in a compact manner. 
       FIG. 4  illustrates a container  400  according to a further embodiment of the invention. The container of this embodiment is a bottle  400  having an open end  405  for receiving the nozzle  140  of the pump  100 . In some embodiments, a lid  410  is provided to form a sealed enclosure with the bottle  410 . The bottle  400  may be formed by, for example, an injection moulding process. The lid  410  may fasten to the bottle by means of a press or screw fit, as will be appreciated. Alternatively, the lid  410  may be moveable affixed to the bottle  400  by means of a hinge such that the lid  410  is moveable between an open position and a closed position. 
     The container  300 ,  400  of either the first or second embodiment may be formed of a material suitable to form a substantially impermeable enclosure, such that a liquid placed within the enclosure i.e. the medication  120  does not leak or permeate through the walls of the container  300 ,  400 . The container  300 ,  400  may be made from relatively rigid or flexible material. Rigid materials may include metals such as aluminium or steel, glass, or plastics such as polyethylene, polypropylene, polycarbonate, cyclic olefin polymers/copolymers, polyvinyl chloride and polymethylmethacrylate. Flexible materials may include plastics such as cellophane, polyolefins, including polyethylene, polymethylpentene and polypropylene, polyvinyl chloride, polyethylene terephthalate (PET), and fluoropolymers, although other materials may be envisaged. A preferred material for a flexible container is polyethylene terephthalate. Furthermore, the container  300 ,  400  may be made from a flexible metal foil, such as aluminium foil, alone or laminated to or coated with one or more flexible plastic materials and/or paper. 
     In order to capture particularly the drug substance of the liquid medication  120 , one or more interior surfaces of the container  300 ,  400  are associated with activated carbon cloth. Preferably, the one or more surfaces are major interior surfaces of the container  300 ,  400 , such as interior surfaces of the first and/or second sheets  310 ,  320  of the pouch  300  or walls of the bottle  400 . 
     Activated carbon (or activated charcoal) is a highly porous form of carbon with a very high surface area available for adsorption of a range of different molecules. It is produced in several forms including powders and granules. It is also possible to make fabrics of activated carbon (“activated carbon cloth”). Such activated carbon cloth may be a cloth formed from activated carbon (“pure activated carbon cloth”) or may be a fabric which is impregnated with activated carbon, such as in the form of fibres, strands, granules or powder. In the latter scenario, the fabric may also contain components to provide other properties such as liquid absorbency. 
     The activated carbon is associated with the one or more walls of the container  300 ,  400  by affixing, impregnating or otherwise attaching an activated carbon cloth to the one or more walls. By associating one or more interior surfaces of the container  300 ,  400  with the activated carbon cloth, when the container  300 ,  400  is inverted during use i.e. it is held with its open end facing downward to allow upright insertion of the spray  100  into the container  300 ,  400 , the activated carbon cloth is retained therein. Furthermore, the properties of the activated carbon cloth, such as surface density, adsorptive surface area and, in some embodiments the form of pure activated carbon cloth, may be selected appropriately for adsorbing drugs intended to be disposed in the container. 
     The activated carbon cloth may be affixed, either directly or indirectly, as will be explained, to the interior surface(s) of the container  300 ,  400 . The activated carbon cloth may be affixed to the one or more interior surfaces of the container  300 ,  400  by an adhesive. The adhesive may be applied, for example, by spray, to the interior surface(s) of the container  300 ,  400  and the activated carbon cloth brought into contact with the adhesive whilst still wet so as to bond the activated carbon cloth to the surface(s). 
     The inner surface(s) of the container  300 ,  400  may be pure activated carbon cloth or a fabric including activated carbon, as described above. Preferably pure activated carbon in the form of carbon cloth is associated with the one or more interior surfaces of the container  300 ,  400 . Pure activated carbon cloth may be obtained from a number of suppliers including Chemviron Carbon (Zorflex (®)), Taiwan Carbon Technology Company (KOTHmex (R®)), MAST Carbon International (C-Tex) and Freudenberg. 
     The adsorptive properties of pure activated carbon cloth can be expressed in terms of parameters such as surface area and surface density of the material. 
     The pure activated carbon cloth for use in embodiments of the invention preferably has a surface density of at least 50 g/m 2 , more preferably at least 70 g/m 2 , and most preferably at least 100 g/m 2 . Embodiments of the invention may also utilise pure activated carbon cloth having an adsorptive surface area of at least 500 m 2 /g, more preferably at least 700 g/m 2 , and most preferably at least 900 g/m 2 . 
     Pure activated carbon cloth is typically available in non-woven, woven or knitted forms. It has been found that the knitted form is preferable for use in embodiments of the invention since it has higher strength and reduced shedding of fibres and dust compared to other forms, such attributes aiding the fabrication into a container. 
     In some embodiments, one or more interior surfaces of the container  300 ,  400  contain one or more other absorbent materials for absorbing liquids, especially water. Absorbent materials include natural materials such as cellulose fibres (e.g. “fluff pulp”) and cotton fibres, and synthetic materials such as rayon and superabsorbent polymers such as cross-linked polyacrylic acids. A preferred absorbent material is airlaid cellulose, in which cellulose fibres are bonded together to form a textile-like material. The airlaid cellulose for use in embodiments of the invention may optionally contain a superabsorbent polymer, such as sodium polyacrylate, to provide additional capacity to absorb liquids. The absorbent material may be directly bonded to the interior surface of the container  300 ,  400  using an adhesive. 
       FIG. 5  illustrates various arrangements of materials within the container  300 ,  400 . A first arrangement is shown in  FIG. 5(   a ) whereby  510  is a wall of the container  300 ,  400  and the activated carbon cloth  520  is affixed to an interior surface of the wall  510 . For example, the activated carbon cloth  520  may be attached to the interior surface of the wall  510  such as by means of an adhesive. A second arrangement is shown in  FIG. 5(   b ) where an absorbent material  530  is affixed to the interior surface of the wall  510  and the activated carbon cloth  520  is affixed to an inwardly facing surface of the absorbent material  530 . For example, the absorbent material  530  may be a sheet of synthetic material having a sheet of activated carbon cloth  520  bonded to the inner surface of the synthetic material.  FIG. 5(   c ) shows a third arrangement whereby the activated carbon and absorbent materials are mixed into a single layer  540  which is affixed to the interior surface of the wall  510 . The layer  540  may be activated carbon which is woven or otherwise incorporated into the absorbent material. It will also be realised that whilst not specifically illustrated one or more of the inner surfaces of the container  300 ,  400  may be associated with the activated carbon cloth, whilst one or more other, different, interior surfaces are associated with the absorbent material. 
     Adhesives suitable for bonding the layers of materials include those which are active at room temperature and atmospheric pressure and those which are activated by the application of heat and/or pressure and/or the uptake of moisture. 
     An example method of constructing an embodiment of the invention will now be explained with reference to  FIG. 6 . 
     Firstly, as shown in  FIG. 6(   a ) a layer of polyethylene terephthalate (PET)  610  is bonded, using a moisture-curing polyurethane adhesive, to one face of a strip of absorbent material  620  comprising an airlaid cellulose containing sodium polyacrylate and polyester/polyethylene bicomponent fibre (binding agent). This forms a PET/absorbent laminate. The width of the laminate is approximately 50 mm, although it will be realised that other widths are envisaged. 
     As shown in  FIG. 6(   b ), to the other, opposing, face of the absorbent material  620  a heat-sealing emulsion coating  630  (styrene acrylic copolymer) is applied and allowed to dry. 
     A strip of knitted pure activated carbon cloth  640  with a width of slightly less than the PET, i.e. approximately 40 mm, is placed centrally onto the absorbent face of the PET/absorbent laminate  61 ,  620  such that an approximately 5 mm wide section of absorbent material  620  is left exposed to either side of the activated carbon cloth  640  as shown in  FIG. 6(   c ). Heat  650  is applied to the activated carbon cloth  640  in order to activate the styrene acrylic copolymer adhesive  630  and thereby bond the activated carbon cloth  640  to the absorbent layer  620 . 
     The resulting strip of PET/absorbent/activated carbon cloth laminate  610 ,  620 ,  640  is subsequently cut into desired lengths to form a container of approximately half of the length. For example, the laminate may be cut into lengths of approximately 60 mm. A fold is made approximately 45 mm from the end of each cut piece of material with the PET  610  facing outwards and the activated carbon cloth  640  facing inwards. Heat is applied to the edges of material  610 , where no activated carbon cloth  640  is present; the heat activates the styrene acrylic copolymer adhesive  630  and bonds the edges to form a pouch as shown in  FIG. 6(   d ). 
     A strip of finger-lift tape  660  is applied to a flap formed at a top of the pouch, under which is a layer of adhesive to allow the flap to be sealed to the pouch body on removal of the tape, as shown in  FIG. 6(   e ). 
     It is envisaged that a preferred means for disposal of the container according to embodiments of the invention is in waste disposal i.e. domestic waste disposal. Embodiments of the invention may be envisaged which are suitable for disposal in a fluid flowing conduit, such as a drain. In other words, embodiments of the invention may be envisaged which are suitable for disposal by flushing down a toilet. 
     An embodiment of the invention relates to a container, for example a flexible pouch as described with reference to  FIGS. 5 and 6 , with enhanced flushability. As embodiments of the present invention are suitable for use with liquid medicines, it may be assumed that a water-tight container should be utilised i.e. formed by the PET layer  610  shown in  FIG. 6 . However, problems have been noted with the efficient disposal of such water-tight containers down liquid flowing conduits, such as drains, wherein the container may float and be resistant to being readily carried away with the liquid flow, for example down the toilet. In these situations, the container may require a number of flushes to be expelled from the bowl of a toilet. It has been surprisingly found that this problem may be overcome by causing embodiments of the invention to be susceptible to liquid ingress i.e. by allowing water to penetrate into the container and to allow escape of air, for example entrapped within the absorbent material. In this way, the ease and speed of flushing can be enhanced by increasing the rate of water uptake into the container. 
     In some embodiments of the invention, liquid ingress is achieved by using a lower density of absorbent layer, which is less prone to entrap air, and/or by adding features to facilitate liquid entry into the container. In this way an outer wall of the container is formed to be at least partly liquid permeable. 
     Referring to  FIG. 7 , one such feature which permits liquid ingress is the inclusion of one or more holes  710  or other perforations into an outer wall of the container. Such perforations  710  may be uniformly distributed across the surface of the container wall or, preferably, located in specific areas, for example adjacent to the seams or flap in the case of a pouch, such shown in  FIG. 7 . These latter locations minimise a possibility of liquid held within the absorbent layer of the container coming into contact with the fingers of any individual handling the container. Alternatively, or in addition, one or more apertures  810  may be included in a seam of a pouch to permit or enhance the rate of liquid uptake into the pouch, such as illustrated in  FIG. 8 . The apertures  910  permit liquid flow into the pouch via the seams. 
     Enhanced flushability may also be achieved by including features which permit the container to be conveniently broken i.e. torn into two or more pieces, such as by adding one or more notches  910  into one or more of the seams of the pouch, such as illustrated in  FIG. 9 . Optionally a series of perforations may be provided adjacent to said notches  910  in order to aid tearing of the pouch across its width. 
     To determine whether a particular drug compound is suitable for disposal using this invention, its adsorption to activated carbon in water or any other suitable vehicle may be measured using the following procedure: 
     i) A solution of the drug compound is prepared, preferably in water or another aqueous medium. A sample of the solution is analysed for drug content using a suitable technique, such as high performance liquid chromatography (HPLC).
 
ii) The drug solution is added to activated carbon cloth.
 
iii) The drug solution and activated carbon cloth are mixed together in a vial, preferably with gentle mixing or agitation.
 
iv) After a suitable period of time, for example 10 minutes, a sample of solution is removed from the vial and analysed for drug content. If there has been a significant reduction in drug content, this will signify that the drug has adsorbed to the activated carbon cloth and will be suitable for use with this invention.
 
     This invention is suitable for use with any drug which adsorbs to and is retained by activated carbon cloth. Drugs which are especially preferred for use with this invention are opioid analgesics, including fentanyl, sufentanil, alfentanil, morphine, diamorphine, etorphine, codeine, oxycodone, oxymorphone, hydromorphone, hydrocodone, buprenorphine, pethidine, butorphanol, levorphanol and methadone. 
     In use, the user, such as the patient intending to administer the medication  120  inserts the nozzle  140  of the spray  100  into the opening of the container  300 ,  400 . The user then actuates the pump  130 , for example by applying a force between the bottle  110  and the pump  130 , such that a spray of liquid is emitted from the nozzle into the container  300 ,  400 . The activated carbon cloth associated with the one or more interior surfaces of the container  300 ,  400  captures at least some of the one or more drugs present in the liquid, thereby aiding safe disposal of the medicine. In some embodiments, the liquid in which the drug is dissolved is also at least partially absorbed by the absorbent material present within the container  300 ,  400 . Furthermore, in some embodiments, the container  300 ,  400  may also be sealed to physically contain the medicine for safe disposal. Advantageously, embodiments of the invention allow the capture and safe containment of medicines, particularly dispensed in the form of a spray. 
     All of the features disclosed in this specification (including any accompanying claims, abstract and drawings), and/or all of the steps of any method or process so disclosed, may be combined in any combination, except combinations where at least some of such features and/or steps are mutually exclusive. 
     Each feature disclosed in this specification (including any accompanying claims, abstract and drawings), may be replaced by alternative features serving the same, equivalent or similar purpose, unless expressly stated otherwise. Thus, unless expressly stated otherwise, each feature disclosed is one example only of a generic series of equivalent or similar features. 
     The invention is not restricted to the details of any foregoing embodiments. The invention extends to any novel one, or any novel combination, of the features disclosed in this specification (including any accompanying claims, abstract and drawings), or to any novel one, or any novel combination, of the steps of any method or process so disclosed. The claims should not be construed to cover merely the foregoing embodiments, but also any embodiments which fall within the scope of the claims.