Abstract:
A swab applicator for containing and dispensing cyanoacrylate adhesives is disclosed. The device comprises a tube applicator with a valve to contain the cyanoacrylate until use. The valve can be a ball, a bead or a capsule, or it can be an oblong object having a channel closed at one end. The device further comprises an absorbent material which is saturated by cyanoacrylate for application upon opening of the valve. The device can be heat sterilized using dry heat sterilization without rupturing prematurely from pressure generated during the sterilization process.

Description:
BACKGROUND OF THE INVENTION  
       [0001]     1. Field of the Invention  
         [0002]     The present invention relates to a disposable device for dispensing cyanoacrylate compositions, a method for dispensing said compositions and methods for manufacturing said devices.  
         [0003]     2. Background  
         [0004]     It is known to use 2-cyanoacrylate esters as adhesives for bonding tissue in medical or surgical procedures performed upon the human or animal body. 2-cyanoacrylate esters polymerize rapidly, and often instantaneously, upon contact with tissue or body fluid. In these applications, the adhesive composition can be used to close wounds, as well as for covering and protecting surface injuries such as lacerations, abrasions, burns, sores and other open surface wounds. These are commonly applied from small tubes of the monomeric adhesive. As the small tube&#39;s contents are typically not consumed, the container must either have a re-closable cap, or else the remaining contents must be disposed of. However, the high reactivity of the cyanoacrylates requires that the tube be re-closed quickly to avoid polymerizing the entire tube. The 2-cyanoacrylate is often dispensed onto a cotton swab and then applied to the wound. As the surface of the cotton swab often has enough moisture to initiate polymerization of the cyanoacrylate monomer, it can be difficult to apply the cyanoacrylate to the swab, close the container, and pick up the swab and apply the adhesive with enough time before the adhesive starts to polymerize.  
         [0005]     U.S. Pat. No. 6,779,938 discloses a disposable device wherein the composition to be dispensed is contained in a sealed container within the device, which has a means to open the container, and an applicator end.  
         [0006]     U.S. Pat. No. 5,100,028 discloses a flexible fluid dispenser which is sealed at one end and sealed at the second end with a shaped seal which is said to focus pressure forces generated within the vessel when external pressure is applied, to open the seal in the region of the seal in which the forces are focused in a predictable fashion.  
         [0007]     Puritan Medical Products markets a swab device under the name Liquishield popule, which comprises a tubular container containing a cyanoacrylate adhesive wherein gentle squeezing pressure on the tubular container causes hydrostatic pressure to build up throughout the tube and causes a rupture at the weakest point. This weak point has been deliberately created by melting a thin spot in the wall of the tube. A foam applicator pad covers the weak spot and as the adhesive escapes it can be spread using the applicator pad. The mechanism to generate the weakness appears to be intrinsically variable, since the pressure needed to release the fluid is very variable, with some Popules™ requiring significant force to open, and others bursting in transit.  
       BRIEF SUMMARY OF THE INVENTION  
       [0008]     The present invention comprises a disposable device for dispensing cyanoacrylate compositions. In one embodiment of the invention, the device comprises a swab applicator which contains a cyanoacrylate composition. The swab applicator device of the invention is closed at one end and covered with a swab applicator with the cyanoacrylate composition contained by a valve which can be readily opened when desired. The device may be heat sterilized. The features and advantages of the device and compositions of the present invention will become apparent from the following more detailed description.  
     
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0009]     For a more complete understanding of the features and objects of the invention, reference should be made to the following detailed description of the invention and the accompanying drawings, in which:  
         [0010]      FIG. 1  is a lateral view of one embodiment of the invention prior to the swab being sealed.  
         [0011]      FIG. 2  is a lateral cutaway view of one embodiment of the invention prior to the swab being sealed.  
         [0012]      FIG. 3  is a top lateral view of one embodiment of the invention after sealing.  
         [0013]      FIG. 4  is a side lateral cutaway view of one embodiment of the invention after sealing.  
         [0014]      FIG. 5  is a top view one embodiment of the invention illustrating where the valve can be snapped to open the valve.  
         [0015]      FIG. 6  is a lateral cutaway view of the invention after the valve has been opened.  
         [0016]      FIG. 7  is an expanded view of the circled area of  FIG. 6 .  
         [0017]      FIG. 8  is a lateral view of another embodiment of the invention prior to the swab being sealed.  
         [0018]      FIG. 9  is a lateral cutaway view of another embodiment of the invention prior to the swab being sealed.  
         [0019]      FIG. 10  is a top lateral view of another embodiment of the invention after sealing.  
         [0020]      FIG. 11  is a side lateral cutaway view of another embodiment of the invention after sealing.  
         [0021]      FIG. 12  is a top view of another embodiment of the invention illustrating where the valve can be crushed to open the valve.  
         [0022]      FIG. 13  is a lateral cutaway view of another embodiment of the invention after the valve has been opened.  
     
    
     DETAILED DESCRIPTION OF THE INVENTION  
       [0023]      FIGS. 1 and 2  are lateral and cutaway views of one embodiment of an applicator  100  in accordance with the invention. Applicator  100  comprises a hollow tube  101  with one end,  103 , being open after filing with a cyanoacrylate composition, with a second end being covered by an absorbent material,  102 . The cyanoacrylate composition,  110 , is contained within the hollow tube housing by a valve,  104 . The valve can be a cylinder which comprises a channel which runs longitudinally down the cylinder. The channel is sealed at one end.  
         [0024]     When the valve is inserted into the hollow tube, it is oriented so that the sealed end of the channel is towards the second end which is covered with the absorbent material. In order to provide a liquid tight seal, the valve is sealed to the interior wall of the hollow tube,  105 , prior to filling, at the end of the valve nearest the first end where the valve is inserted, and the device filled with cyanoacrylate composition. The method of sealing the valve to the interior wall can be either heat sealing, or via ultrasonic sealing. To form this seal, a sealing mechanism presses the wall of the hollow tube together with the valve to contact the two surfaces together. The sealing mechanism then applies to the hollow tube sufficient heat or ultrasonic energy to cause the vessel walls to melt. After the heat or ultrasonic energy is no longer applied, the walls of the tube fuse together with the valve to form the seal.  
         [0025]      FIGS. 3 and 4  are lateral and cutaway views of the applicator after the tube is sealed at the first end,  103 .  
         [0026]     To open the valve and release the contents of the swab, the valve,  104 , of the applicator is snapped or bent below the heat seal to open it at  112 , as illustrated in  FIG. 5 . The valve breaks and ruptures into two pieces. This allows the cyanoacrylate composition to flow through the longitudinal channel in the valve, through the leak path  108 , into the open space  109  between the swab body  101  and the valve  104 , and into the absorbent material covering the end of the applicator as illustrated in  FIG. 6 , and expanded view  FIG. 7 .  
         [0027]     The embodiment depicted in  FIGS. 1-7  of the present invention utilizes a cotton swab applicator with a valve manufactured and sold by Swabplus Inc. in Pomona, Calif.  
         [0028]      FIGS. 8 and 9  are lateral and cutaway views of another embodiment of an applicator  100  in accordance with the invention. Applicator  100  comprises a hollow tube  101  with one end,  103 , being open after filing with a cyanoacrylate composition, with a second end being covered by an absorbent material,  102 . The cyanoacrylate composition,  110 , is contained within the hollow tube housing by a valve,  114 , which is a ball, a bead or a capsule. In order to provide a liquid tight seal, the valve is sealed to the inner wall of the hollow tube by heat or ultrasonic means prior to filling. Alternatively, the valve may designed to be pressure fit into the hollow tube.  
         [0029]      FIGS. 10 and 11  are lateral and cutaway views of the applicator after the tube is sealed at the first end,  103 .  
         [0030]      FIGS. 12 and 13  illustrate how the valve,  114 , of the applicator is compressed or crushed to open the valve and release the contents of the applicator. The valve  114  is hollow, and is constructed of a non-rubber material. Thus when the valve is compressed or deformed at  118  in  FIG. 12 , it does not recover, but rather permanently deforms or ruptures,  117 . This allows the cyanoacrylate composition to flow through the tube and into the absorbent material as illustrated in  FIG. 13 .  
         [0031]     It is important that the cyanoacrylate composition contained within the hollow tube of the applicator be protected from moisture, so that polymerization of the cyanoacrylate is not initiated prior to use. Suitable materials of construction for the hollow tube of the applicator should be capable of being a barrier to the diffusion of moisture into the device prior to use. Suitable materials for the hollow tube  101  and valves  104  and  114  include polyolefins such as high density polyethylene (HDPE), polyethylene, polypropylene and the like. High density polyethylene (HDPE) and polypropylene are preferred. High density polyethylene (HDPE) is most preferred. The term high density polyethylene (HDPE) as used herein refers to high density homopolymers of ethylene, and high density copolymers of ethylene with alpha olefins. The term polypropylene as used herein refers to homopolymers of propylene, as well as copolymers of propylene with ethylene and other alpha olefins. The polyolefin may also be fluorinated to prevent the entry of moisture and improve product stability.  
         [0032]     The cyanoacrylate composition  110 , comprises a cyanoacrylate monomer or monomers which can be selected from the group consisting of alkyl 2-cyanoacrylate, alkenyl 2-cyanoacrylate, alkoxyalkyl 2-cyanoacrylate, or carbalkoxyalkyl 2-cyanoacrylate. The alkyl group of the cyanoacrylate monomer or monomers preferably has 1 to 16 carbon atoms, and includes cycloalkyl functionality. Suitable cyanoacrylates include for example methyl 2-cyanoacrylate, ethyl 2-cyanoacrylate, n-propyl 2-cyanoacrylate, iso-propyl 2-cyanoacrylate, n-butyl 2-cyanoacrylate, iso-butyl 2-cyanoacrylate, hexyl 2-cyanoacrylate, n-octyl 2-cyanoacrylate, 2-octyl 2-cyanoacrylate, 2-methoxyethyl 2-cyanoacrylate, 2-ethoxyethyl 2-cyanoacrylate and 2-propoxyethyl 2-cyanoacrylate. Preferred cyanoacrylates include n-butyl 2-cyanoacrylate, n-octyl 2-cyanoacrylate and mixtures thereof.  
         [0033]     The cyanoacrylate compositions of the present invention can be stabilized against premature polymerization with anionic and free-radical polymerization inhibitors. Anionic polymerization inhibitors, known in the art include soluble acidic gases (for example sulfur dioxide), and phosphoric, carboxylic and organic sulphonic acids. Free-radical polymerization inhibitors include hydroquinone, t-butyl catechol, hydroxyanisole, butylated hydroxyanisole and butylated hydroxytoluene. Preferred polymerization inhibitors include butylated hydroxyanisole, hydroxyanisole, butylated hydroxytoluene, and mixtures thereof. Free-radical polymerization inhibitors can be used at levels from about 10 ppm to about 200 ppm, depending on the particular polymerization inhibitor. Typical amounts of free-radical polymerization inhibitors can be from about 20 to about 100 ppm.  
         [0034]     The applicators of the device can be filled using commonly available filling equipment. Cyanoacrylate monomers are very sensitive to moisture and other contaminants. Accordingly, filling equipment must be kept scrupulously clean and free of contaminants. Any pressurized air used to drive pumps or pressurize liquid reservoirs must be scrupulously dried and filtered to remove contamination. In addition to air pressure driven filing equipment, positive displacement pumps may also be utilized. Positive displacement pumps are preferred.  
         [0035]     After filing the device with a cyanoacrylate composition, the end  103  is closed by one of several closing means. These include heat sealing to press the end of the tube together into a flat surface and then fuse them through application of sufficient heat to fuse the polyolefin, and ultrasonic welding wherein the end of the tube is pressed flat and then fused through application of sufficient ultrasonic energy to melt the walls of the tube. After the heat or ultrasonic energy is removed, the surfaces fuse together.  
         [0036]     The applicator device of the invention may be sterilized. Cyanoacrylate compositions can be sterilized either by exposure to gamma irradiation, or by dry-heat sterilization. U.S. Pat. 6,136,326 and U.S. patent application Ser. No. 10/944,635 disclose dry-heat sterilization of cyanoacrylate adhesive compositions and their disclosures are herein incorporated by reference. Applicator devices of the invention are capable of withstanding the pressures generated during the sterilization process without rupturing or leaking.  
         [0037]     The following examples are offered to illustrate embodiments of the invention, and should not be viewed as limiting the scope of the invention.  
       EXAMPLE 1  
       [0038]     Polypropylene swabs from Swabplus Inc., located at 9669 Hermosa Avenue Rancho Cucamonga, Calif. 91730 USA, having an oblong valve were filled by hand through a syringe with 0.20 g of a medical cyanoacrylate (FlexAid) available from Chemence Medical Inc., 185 Bluegrass Valley Parkway, Alpharetta, Ga. The open end of the swab was pressed together and heat-sealed with a pair of pliers and a flame. The closed end was fitted with a polyurethane foam tip.  
         [0039]     The swap was striped with a magic marker one inch from the closed foam tip. The liquid contents were dispensed from the applicator by bending at the stripe to one side until it snapped. The foam capped tip, filled with the formulated liquid cyanoacrylate was easily dispensed onto the skin surface. In this way a low viscosity formulation could be applied without spillage or dripping of the adhesive onto unwanted areas.  
       EXAMPLE 2  
       [0040]     Polypropylene swabs as above were filled with formulated liquid bandage, manufactured by Closure Medical Corporation (Lot 092106), sold by Johnson and Johnson as Band-Aid® liquid bandage using a 1 ml pipette. Swabs were filled within a range of 0.153-0.204 g. The open end was pressed together and heat-sealed using a Uline  8 ″ Impulse Sealer set at 8 for 15-20 seconds. The swabs were then fitted with an activated foam tip obtained from the Band-Aid liquid bandage kit. The liquid bandage was applied to a minor abrasion by squeezing four drops onto the end of the foam end of the activator and compared to the application on a similar wound with the swabplus device by applying as described in example one. Applying the liquid bandage as directed presents an opportunity to spill the liquid. The swab plus applicator permits a controlled application with little chance of spillage. A fill between 0.08-0.10 g is sufficient to saturate the foam tip and cover a minor wound like a paper cut.  
       EXAMPLE 3  
       [0041]     Polypropylene swabs from Swabplus Inc., located at 9669 Hermosa Avenue, Rancho Cucamonga, Calif. 91730 USA, were dis-assembled to extract the brittle polypropylene valve. These were inserted into LDPE (Ablex 201) and HDPE (Alblex 503) tubes (0.146×0.168×6.0 inch) obtained from Action Technology located at Route 10 East, P.O. Box 111, Clinton, Ill. 61727. The valves were fixed in the device using a soldering iron to seal the outside wall of the valve to the inside wall of the tube. The polyethylene swabs, prepared as above, were filled with a formulated FlexAid liquid adhesive (RCM-11-034), manufactured by Chemence Medical, Inc. using a 1 ml pipette. Swabs were filled in a range of 0.17-0.19 g. The open ends of the swabs were cut to an approximate 3″ length, and the opening pressed together and heat-sealed with a heated pair of pliers. The closed end was fitted with a polyurethane foam tip. The liquid contents were dispensed from the applicator by bending the tube at the valve end to one side until it snapped. The foam capped tip, filled with the formulated liquid cyanoacrylate was easily applied onto the skin surface. In this manner a low viscosity formulation was applied without spillage or dripping of the adhesive onto unwanted areas.