Flexible tourniquet pad

Abstract

A flexible hemostatic pad formed from a hemostatic powder compressed onto or into a velvety backing substrate, which may include a hydrophilic polymer such as a cationic ion exchange resin, is provided for controlling bleeding at a wound site.

Description

[Technical field]

[0001] The present invention relates generally to flexible hemostatic pads that are applied topically to control and / or arrest bleeding and methods for making such pads. [Background technology]

[0002] Hemostatic products are known in the prior art in both powder and tablet form. For example, hemostatic products composed of more than 80% hydrogen resin have been used in both powder and rigid tablet form to reduce and / or stop bleeding, as well as to absorb exudate. Powder forms typically conform to any wound surface regardless of shape, including curved surfaces such as fingers, but can be cumbersome to use. Furthermore, some powder forms may not adhere well to the wound site. Tablet forms are typically rigid and may disintegrate or crack when subjected to force. To overcome this tendency to disintegrate, the tablet form must be made relatively thick compared to its diameter. Furthermore, rigid compressed powder tablets are inflexible and therefore can only be used on relatively flat or small dimensional surfaces. For example, hemostatic compressed powder tablets have been known to be useful in vascular access procedures where bleeding control is required at an arterial puncture site and where the site is relatively flat or has a small surface area. However, when the wound area is located or on a body part that is rounded (such as a finger, arm, or leg), uneven, or has a larger surface area, the tablet product is less useful because it lacks mechanical flexibility.

[0003] Hemostatic tablets may also suffer from structural weaknesses that may manifest as cracks during shipping and construction. The product must arrive intact to the customer and therefore must be strong enough. Tablets are limited in size by thickness to surface area ratio to make a structurally sound tablet. To prevent cracking and provide sufficient structural strength, the tablet may become very thick and therefore aesthetically unacceptable. Larger tablets are also more susceptible to improper application to curved wound surfaces. For example, a small tablet may be applied to the wrist or finger location to stop bleeding of a small wound, but a larger tablet cannot wrap around the wrist or finger for a larger wound along the curved surface of the wrist. The same is true for nearly all tablets with respect to fingers.

[0004] One example of a powdered hemostatic product is disclosed in U.S. Pat. No. 6,187,347 to Patterson et al. ("Patterson"), which is incorporated herein by reference in its entirety, and which: (1) hydrates in the presence of blood to produce Fe +++ The present invention discloses a free-flowing powder for stopping bleeding from a wound by (1) providing a substantially anhydrous compound of ferrate that produces clotting, clots blood, and produces oxygen, and (2) applying the compound to the wound for a time sufficient to arrest blood flow, reduce microbial populations, and form a protective coating on the wound. In one embodiment, an acidic cation exchange material (in the form of a hydrogen resin) is mixed with the ferrate to provide a protective coating for protecting the wound. Combining the ferrate with the acidic cation exchange resin provides a form of Fe that allows the iron cations to covalently interact with the blood to produce clotting and to form a protective scab on the wound that has antimicrobial properties. +++ is generated.

[0005] In the manufacture of the wound sealing powder disclosed by Patterson, the cation exchange resin is prepared in a washed hydrogen form, dried at about 110° C. for 24 hours, and then pulverized in a grinder to about 100 mesh size. 100 mesh powder particles are 149 microns (or 0.149 mm) in diameter.

[0006] WoundSeal® topical powder, also commercially available from Biolife LLC, currently consists of a hydrophilic polymer (such as the hydrogen resin mentioned above) and potassium ferrate. To use WoundSeal®, the wound is first cleansed and the powder is poured into the wound after bleeding resumes. This is because blood must be present for the powder to work. The powder is then compressed onto the wound to stop the bleeding, which can be a messy application due to the powder.

[0007] WoundSeal® topical powders are typically made from a similar weight mixture of potassium ferrate and a hydrophilic polymer (hydrogen resin). Weight mixtures ranging from 1:3 to 1:12 typically inhibit bleeding, depending on the particular application. In one embodiment, the ferrate (after grinding) and resin (after drying) are mixed and then ground in a turbo mill. A turbo mill is a rotor mill type grinder that utilizes a high speed rotor contained in a grinding chamber with a screen to reduce particle size by collisions with the rotor and screen. Particle size is controlled by rotor speed and screen opening size. Based on the size of the unground beads and the size of the openings in the grinding screen, a portion of the unground (whole) beads pass through the grinding process and there is typically no post-grinding screening process.

[0008] The turbo mill has a continuous feed to the mill and a continuous flow of particles from the mill that pass through a control screen. The screen used in this embodiment is a 1 mm screen, and the mill is operated at a production rate sufficient to obtain WoundSeal® topical powder. After production, the powder is stored in a sealed container, such as a plastic tub, to prevent the powder from rehydrating until it can be packaged into a consumer package for sale.

[0009] As mentioned above, hemostatic products other than powders are also known in the art. For example, U.S. Patent No. 8,961,479, Hen et al. ("Hen"), incorporated herein by reference in its entirety, discloses a compressed hemostatic tablet form made from a hemostatic powder that may include potassium ferrate and a hydrophilic polymer (sometimes referred to as a cationic ion exchange resin-hydrogen resin). The powder is pressure-formed into a rigid tablet for delivery to a bleeding wound. The tablet improves the rate of adhesion to the bleeding wound surface and allows for significantly greater and more uniform pressure to be applied by manually compressing the tablet to the wound site compared to a thin layer of dusted hemostatic powder. Sometime after a seal is formed from the interaction of blood or exudate with the direct contact surface of the tablet, the bulk of the unused tablet peels away from the seal due to expansion from moisture absorption at the blood-tablet interface, facilitating cleanup. If the unused portion of the tablet is not removed from the wound site, the reservoir of the hemostatic dressing will stop further bleeding. The tablet can be applied in any surface orientation and can be of any possible shape and thickness. Unlike known hemostatic powders, the tablets can be applied to vertical surfaces.

[0010] Hen's compressed hemostatic tablet is a rigid, stiff product that will crack and break if bent sufficiently. A commercial form of hemostatic tablet is sold by Biolife, LLC (Sarasota, Florida) under the trademark StatSeal® Disc. While useful in many situations to arrest blood flow, especially when used in various vascular procedures, Hen's hemostatic tablet is less useful in areas of the body that are not flat or have a relatively small surface area. The maximum surface area of ​​the StatSeal® Disc can be calculated from a circular tablet with a diameter of 22 mm. To allow the StatSeal® Disc to fit around an indwelling vascular catheter, the tablet is made from two pieces and a foam mass is used to bend it open around the catheter line and then closed.

[0011] Currently, StatSeal® Discs are made with a hydrophilic polymer (the hydrogen form of an ion exchange resin) and potassium ferrate. The hydrogen resin is dried before being combined with the ferrate and compressed to prevent the resin from reacting with the ferrate.

[0012] The foregoing examples of the related art and limitations associated therewith are intended to be illustrative and not exhaustive. Other limitations of the related art will become apparent to those of ordinary skill in the art upon reading this specification and studying the drawings. Summary of the Invention [Means for solving the problem]

[0013] Briefly, the present invention relates to a hemostatic product comprising, in one embodiment, a compressed hemostatic powder pad that is flexible and can bend to be applied to curved surfaces without breaking. The present invention generally relates to a topically applied flexible hemostatic pad that stops bleeding. The pad is made by compression of a hemostatic powder incorporated into a fibrous velvety backing. The resulting pad is flexible and can be conveniently applied to any wound surface, regardless of shape, compared to a rigid tablet made without a velvety material. The resulting pad can be cut to shape during manufacturing, with the size or length of the pad being limited only by the manufacturing process. The present invention also relates to a method of manufacturing a flexible wound sealing hemostatic pad. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0014] Reference will now be made in detail to the embodiments of the invention, one or more examples of which are set forth below. Each example is provided as an explanation of the invention, not a limitation of the invention. Indeed, it will be apparent to those skilled in the art that various modifications and variations can be made in the present invention without departing from the scope or spirit of the invention. For example, features illustrated or described as part of one embodiment can be used in another embodiment to yield still further embodiments. The following embodiments and aspects thereof will be described and illustrated in conjunction with systems, tools, and methods, which are intended to be exemplary and illustrative rather than limiting in scope. Various embodiments reduce or eliminate one or more of the problems discussed above, while other embodiments are directed to other improvements.

[0015] Therefore, it is intended that the present invention encompass such modifications and variations as fall within the scope of the appended claims and their equivalents. Other objects, features and aspects of the present invention are disclosed in or are apparent from the following detailed description. It should be understood by those skilled in the art that the present discussion is merely a description of exemplary embodiments and is not intended to limit the broader aspects of the present invention.

[0016] It is to be understood that the examples and embodiments described herein are for illustrative purposes only, and that various modifications or changes in light thereof will be suggested to those skilled in the art and are to be included within the spirit and scope of this application and the scope of the appended claims. Furthermore, any element or limitation of any invention or embodiment thereof disclosed herein may be combined with any and / or all other elements or limitations (individually or in any combination), or with any other invention or embodiment thereof disclosed herein, and all such combinations are contemplated within the scope of the invention, without limitation thereto.

[0017] The pads are made by compressing the hemostatic powder into a fibrous backing with vertically oriented velvet-like fibers. Velvet is typically known as a type of tufted woven fabric with short dense pile with evenly distributed cut threads that give it a unique soft feel. For example, velvet materials are often made from tightly woven silk, cotton, or nylon fabrics with a thick short pile on one side. As used herein, the term "velvet-like" is defined as any fabric material that is velvet or mimics the characteristics of velvet, is soft, has a dense pile of fibers on at least one side, and at least some of the fibers extend vertically from the material.

[0018] The resulting pads formed from the hemostatic powder compressed into the velvety material substrate are flexible and convenient to apply to any wound surface, including curved surfaces, compared to the rigid tablets made without the velvety material. The resulting pads have better mechanical integrity than tablets and can be made much larger and with a much larger surface area while using less hemostatic powder than a typical tablet. The resulting pads can also be cut to shape as needed.

[0019] The inventive flexible hemostatic pad of the present disclosure is prepared by compressing hemostatic powder onto a velvety backing having at least partially vertical fibers extending upward. The inventive flexible hemostatic pad provides improved manufacturability and improved delivery and control of application to wound sites that are not substantially flat or larger than those typically used with known rigid compressed powder hemostatic tablets. When densely packed into a flexible hemostatic pad form for topical application, the hemostatic powder adheres more firmly to a particular wound site than either known rigid forms of hemostatic powder or compressed tablets. In previously known rigid forms of hemostatic tablets, unused compressed powder peels off from the tablet / blood interface after time has allowed for fluid absorption and expansion at the interface. Unlike rigid tablets, the compressed powder from this inventive flexible hemostatic pad can be designed to peel off from the seal (as with rigid tablets) or to separate from the velvety material immediately after application leaving a powder / blood seal, or the pad can be left in place to provide a reservoir for the hemostatic dressing as a bleeding control after application. These different designs are based on the amount of compressed powder and the fiber length of the velvety material, which would not be possible without this combination of materials.

[0020] The terms "onto" and "into" when discussing fibers and hemostatic powder added thereto are used interchangeably herein. When used in such context, "unto" and "into" interchangeably mean that the powder is incorporated into the fibers before or during compression. The powder is then bonded to the fibers by compression.

[0021] The hemostatic powder may be a single homogenous powder compressed into a tablet, or the powder may be layered over an initial powder compaction layer. These layers may be fully or partially compressed before adding additional powder, or may be layered as powders with a final compaction or combination.

[0022] To form a flexible tablet, the powder and / or powder layer is compressed onto a fibrous backing having at least some fibers extending from and at least partially oriented perpendicular to the backing. Compression by any known compression method can be performed to form tablets of any size, shape, thickness and configuration. Additionally, during use of the product, various medical hemostatic compression assist devices such as balloons, compression foams, mechanical clamps, compression bandages, etc. can be used during application of the hemostatic pad to the wound.

[0023] Such flexible hemostatic pads may be used as topical dressings for bleeding control associated with small wounds, including control of minor external bleeding and exudates from sutures and / or surgical procedures. Flexible hemostatic pads may be applied to either actively bleeding wounds or to sites that may subsequently experience bleeding. Flexible hemostatic pads may also be used to seal sites oozing exudative fluids to prevent maceration, and to combine with blood or exudates to form a seal, while simultaneously preventing wound drying due to the seal formed.

[0024] The flexible hemostatic pad can be attached to a bandage, a cotton swab, a surgical or dental instrument, a vacuum device, a compression device, a fixation device, or a magnet if a suitable material such as magnetite is mixed with the powder. The tool attached to the flexible hemostatic pad may be straight or curved, rigid or flexible. The fixation device may be a wrap around the body part that includes a means to prevent the wrap from moving. The wrap may apply pressure to the wound or may simply hold the device in place. The compression device may be used to apply pressure to the bleeding wound, such compression may be mechanical, pneumatic, hydraulic, or magnetic. Examples include, but are not limited to, preventing movement by using adhesives or bandages / devices to the skin, Velcro, buttons, magnets, zippers, stitches, staples, or hooks. The fixation device may be part of the pad, the pad may be attached to the fixation device before application, or additional fixation may be added after the flexible compression hemostatic pad is placed on the wound.

[0025] The hemostatic material (i.e., powder) should have certain characteristics. It must be small enough so that it can be incorporated into the fibrous backing. The hemostatic material must have a sufficient level of absorbency to dehydrate blood at the wound site to reduce and / or stop bleeding. It should be dry enough so that it can be molded and properly bound as a pad or other solid form when processed into a flexible tablet.

[0026] There are also certain characteristics of flexible hemostatic pads that are beneficial. For example, if the hemostatic material compressed onto the backing is taller than the fibers themselves, the tablet can be removed from the wound site after a given time without causing rebleeding. The pad must be thin enough to be flexible, yet supportive enough to be cut with a die.

[0027] Generally, the hemostatic powder composition used to form the flexible hemostatic pad of the present invention may include an effective amount of an insoluble cation exchange resin material, which may be combined with an effective amount of anhydrous ferric acid compounds, other antimicrobial agents, or wound healing materials. The resin may also be used alone. In one embodiment, the powder is pressed into the flexible hemostatic pad by incorporating the hemostatic powder with a backing having a velvety material.

[0028] The hemostatic powder portion of the flexible hemostatic pad may include a mixture of the hydrogen form of a cation exchange resin (hereinafter abbreviated as "hydrogen resin") and an anhydrous ferrate compound, such as potassium ferrate.

[0029] In some cases, other materials can be incorporated into the hemostatic powder to improve performance or add useful features, such as antimicrobial agents, such as zinc oxide, vitamin C, collagen, etc.; processing aids or performance enhancers, such as binders, lubricants, and excipients, including, but not limited to, materials such as magnesium stearate; absorbent components, such as absorbent polymers, e.g., superabsorbent polymers; natural and / or synthetic rubbers, including, but not limited to, sodium carboxymethylcellulose and / or hydroxymethylcellulose; nutrients, such as vitamin C; colorants, such as titanium dioxide; polyvinylpyrrolidone; and / or fibers (in addition to the fibers extending from the backing material), such as medical grade fibers, natural and synthetic rubbers, which may add strength. Materials may be added to the hemostatic powder during formation or may be added to the flexible hemostatic pad after formation. Similarly, materials, such as, but not limited to, silver, chlorhexidine, and polyvinylpyrrolidone, can be incorporated into any portion of the backing material to provide wound benefits.

[0030] It may be necessary for the primary packaging of the pad to have moisture barrier properties. In this case, the packaging must be compatible with the energy form of sterilization. The packaging may also be designed to protect the product from damage.

[0031] The powder component of the flexible hemostatic pad of the present invention can be prepared as follows.

[0032] Ion exchange resins are typically prepared as spheres with particle sizes typically ranging from less than 10 microns for high pressure liquid chromatography, 40-250 microns for ingestible drug delivery resins, and 300-1200 microns for some industrial applications. These sizes are fully hydrated sizes since the majority of all ion exchange resins are used fully hydrated. The resins produced have an average size (diameter) with a Gaussian distribution, and the variation in bead size is based on the manufacturing process. The resins can then be further sized by grinding and / or fractional screening to obtain the appropriate size for the application. Drug delivery systems require similar sizes with a narrow Gaussian distribution to ensure consistent delivery. In industrial liquid processing applications using ion exchange resin beds, if the size distribution is too broad, bead stacking is affected, hindering the flow characteristics through the bed and creating a high pressure drop across the column of ion exchange resin. The pressure drop increases as smaller particles can fit into the spaces between the larger particles, thus hindering the flow of the liquid. Ion exchange resin bridging has the effect of moisture absorption.

[0033] When a dry strong acid cationic resin, such as that in its hydrogen form ("SACR-H"), is applied to blood, the SACR-H floats on the blood surface and rapidly absorbs liquid from the blood. The pores in the resin are small, so they cannot absorb blood solids or large proteins. This rapid absorption of liquid causes solids to pile up underneath the SACR-H while excluding blood solids. These solids continue to pile up until liquid can no longer pass through the barrier of blood cells that has formed. When this barrier is forced into contact with a surface, it adheres to the surface due to the natural glue-like properties of dried blood. If this surface is a bleeding wound, the barrier adheres to the wound site and stops further bleeding.

[0034] When dry, essentially round SACR-H beads are injected into a bleeding site, the beads that come into contact with the blood will adhere to the blood, but additional beads will simply roll off the wound site, especially if the wound site is not horizontally located but instead is on a more vertical surface such as the neck, chest, or head of a standing patient. This is also observed when the wound site is on a curved part of the body, such as the arm, fingers, or toes. A single layer of beads that may adhere to such rounded or more vertically located skin surfaces will not have sufficient absorption capacity without multiple applications and will be less capable of stopping a bleeding wound. Several layers that absorb enough liquid from the blood may be required to create a barrier strong enough to stop bleeding from the wound. As blood flows, it may remove the hemostatic effect of the powder by constantly eroding the powder.

[0035] To address this need for more powder deposition at the wound site, the resin can be milled into smaller particles, which increases the frictional contact area between the particles (i.e., cohesion between the particles), and therefore increases the angle of repose when the powder is applied. Typically, the amount of unmilled relatively round beads remaining in the powders of the present invention is 5% or less in the final powder.

[0036] This increased angle of repose allows multiple layers of powder to remain on the bleeding wound while reducing the amount of material that easily falls off the wound site during application. In addition to increasing the angle of repose, increasing the squareness also allows the product to better adhere to more sloped or curved wound surfaces.

[0037] SACR-H has a negative pKa (indicative of strong acidity) similar to that of hydrochloric acid. When applied to blood, some of the hydrogen atoms attached to the resin backbone are neutralized, but the remaining hydrogen atoms on the resin backbone have antibacterial properties. Due to the stacking properties, when the whole bead is applied and adheres to the blood barrier on the wound, there are spaces between the beads large enough for bacteria to penetrate against the dense packing created by the more finely ground SACR-H product.

[0038] The appropriate starting material is used along with appropriate milling and screening methodology to increase adhesion of the powder to all skin surfaces by increasing interparticle cohesion. Eliminating "too low" and "too high" fractions or particle sizes narrows and lowers the range of particle size distribution that is acceptable by the present invention to provide the necessary adhesion to the wound.

[0039] The SACR-H used in the hemostatic powder can be purchased from suppliers as spherical beads in the 150-1000 micron size range after drying to a moisture content of less than about 3% (although typical drying results in a moisture content of about 1% or less). The dried SACR-H resin beads are then dispersed onto the wound and ground to an appropriate particle size distribution to allow good adhesion and reduce the amount of powder that cannot adhere to the wound and simply falls off the skin surface during application.

[0040] The hydrogen resin may be the hydrogen form of a 2% cross-linked sulfonated polystyrene resin. The hydrogen resin may be available in totally insoluble, generally circular beads having an average particle size of about 500 microns in diameter (for purposes of this specification, "diameter" and "particle size" are synonymous, with respect to one or more particles), or alternatively, the resin may be available in or ground into much finer fragments averaging a size of 80 microns to 200 microns in diameter.

[0041] One resin that may be used in the preparation of the present invention is the hydrogen resin Purolite CT122 available from Purolite Corporation (Bala Cynwyd, Pennsylvania). However, it will be understood by those skilled in the art that other hydrophilic cationic resins may be used. For example, other forms of resins may be used, including, but not limited to, sodium and calcium resins. While such resins will work, a drawback to their use is that the more tolerable pH effect seen in the hydrogen resin form may be reduced. Additionally, resins with up to 10% or more crosslinking may also be useful in the present invention.

[0042] The resins used can have a variety of particle size distributions, including but not limited to: 1) maximum 10% greater than 1400 microns; 2) maximum 5% less than 850 microns; or 3) maximum 2% less than 425 microns, with the primary particle size range being 850 microns to 1400 microns.

[0043] Ferrate may be added during powder preparation. Ferrate may be purchased or produced by cooking iron oxide with an oxidizing agent and then heating until a ferrate "cake" is produced. If ferrate cake is used, the cake is typically broken into smaller pieces by hand or using known machinery, and then a knife crusher or other known suitable device is used to break the cake. In a typical example, a knife crusher with a 2 mm screen can be used. This breaking process results in ferrate having a particle size of 2 mm or less in diameter.

[0044] One particular ferrate that has proven useful when combined with a cation exchange resin is potassium ferrate, an oxyacid salt by-product of the reaction between ferric acid (H2FeO4) and potassium hydroxide (KOH). Potassium ferrate is produced by the thermal combination of iron oxide (Fe2O3) with potassium nitrate (KNO3). Potassium ferrate readily decomposes in water to produce Fe2O3 and KOH as follows: 2K2FeO4+2H2O→Fe2O3+4KOH+1.5O 2(g)

[0045] The resin is first dried in a static dryer, such as an oven, at a temperature of about 100°C to 110°C for an average of 12.5 days depending on the ambient moisture. In one embodiment, the goal of resin drying is to achieve a moisture content of 3% or less, typically about 1%. During the drying process, the particle size of the resin is typically reduced by dehydration of water molecules from the resin. Drying the resin reduces the resin's ability to transport or exchange protons, and thus the dried resin generally becomes inactive. If the resin is mixed with another dry proton acceptor to deactivate the hydrogen transport mechanism, some drying of the resin is required, but it is expected that moisture contents of the order of 25% may also be useful in the present invention.

[0046] The dried resin may be ground alone in an attritor mill, for example at a production rate of 20-25 kg / hour. Unlike a turbo mill, an attritor mill is an agitated ball mill that uses larger, harder stainless steel balls (e.g., 9-10 mm diameter) that are agitated by rotating agitator arms to grind smaller, softer materials. The grinding action is caused by the impact of the stainless steel balls, the agitator arms, and the sides of the grinding tank. The particle size is controlled by the agitator arm speed, the size of the grinding media, and the grinding time. In one particular embodiment, an attritor mill is used to grind the dried hydrogen resin to an average particle size of about 40 microns (although one skilled in the art will understand that average particle sizes up to 70 microns are suitable for the present invention).

[0047] If ferrate is used, it is screened (typically a 2 mm screen) and then mixed with dry resin in a ratio of 1:2 ferrate:hydrogen resin in certain embodiments to obtain a mixture with a weight ratio of about 1:7 ferrate:hydrogen resin, although weight ratio mixtures in the range of 1:3 to 1:12 will adequately stop bleeding depending on the particular application. This mixture can then be subjected to milling in a turbo mill (described above) using a 0.25 mm screen, for example at a production rate of 20 kg / hr to 25 kg / hr, to obtain an intermediate product which can be processed immediately or stored in a sealed container, such as a plastic tub to prevent rehydration, until the powder can be processed into tablets.

[0048] It should be appreciated that the above milling and forming process can be utilized to form a wound sealing powder consisting solely of hydrogen resin (no ferrates or pigments) and without the 3% moisture level constraint, as described in U.S. Patent Application Serial No. 14 / 147,143, the entirety of which is incorporated herein by reference.

[0049] To form a flexible hemostatic pad, a substrate is used that receives the powder and is compressed with the powder. In particular, a backing can be selected as the substrate, and the backing can be fibrous. The backing can be a natural fir material, a woven or non-woven material, or a flocked material, but all kinds of materials can prove useful in the present invention, provided the fibrous backing has fibers that extend away from the backing itself. A fibrous backing with fibers extending from the substrate, some of the fibers extending perpendicularly from the substrate, is shown below. The following figures are not real-world examples, but are merely for demonstration purposes. [ka]

[0050] The fibrous backings designated may be referred to as "velvety" because such backings generally have fibers relatively uniformly distributed on the surface of the backing in short dense piles. For use in the present invention, it is not necessary that the elongated fibers be entirely vertical or uniformly distributed. Fibrous backings may be used in the present invention if they have at least a sufficient number of fibers with at least partial vertical fiber portions extending vertically away from the backing. For purposes of this specification, "vertical" means extending generally in a straight line away from the horizontal plane of the backing (if the backing is horizontal).

[0051] The use of such velvety materials as a backing allows for the use of a thin layer of hemostatic powder compressed into and onto the material, resulting in a tablet that is flexible enough to be applied where more rigid hemostatic tablets cannot be applied due to the possibility of cracking and breaking. In particular, flocked velvety materials can be useful as tablet backings.

[0052] The flexible hemostatic pad may be designed to be wetted from the underside of the device to facilitate removal from the wound to which it is applied. This can be accomplished in a number of ways, including but not limited to, by inclusion in certain types of porous materials.

[0053] In one embodiment, the present invention can incorporate a thin layer of hemostatic powder, composed primarily of ion exchange resin (>80%), into a velvety material and then compress these components into the final flexible pad. The pad may be used as a stand-alone device or may be incorporated into other devices, such as, but not limited to, hemostatic compression devices, adhesive strips, aesthetically appealing substrates, rigid substrates, etc.

[0054] In one embodiment, the flexible hemostatic pad formation of the present invention provides an improved manufacturing method by eliminating the use of a female mold and significantly reducing the compression force required to form the device compared to hemostatic tablets without a velvety backing. Conventional methods for manufacturing tablets require the use of both a male and female mold. The female mold is filled with powder, which confines the powder in a confined space while the mated male mold compresses the powder into a tablet.

[0055] As part of the present invention, the use of the velvety material eliminates the need for a female mold, since the fibers prevent the powder from spreading laterally as the tablet is compressed. When making an initial rigid tablet without the velvety material, the compression pressure required to produce a commercially stable and functional tablet is approximately 15,000 psi. The incorporation of the velvety material in making the flexible hemostatic pad significantly reduces the compression pressure from 15,000 psi to less than 7,500 psi (7,244 psi in some cases). The exact amount of compression pressure varies depending on a variety of factors, including the specific type of material substrate, the amount of powder, and the type of powder used. The only constraint in selecting the compression pressure is to ensure that, when used, there is enough pressure to keep the compressed powder on the substrate during application and to maintain the flexibility of the substrate.

[0056] The two-component flexible hemostatic pad of the present invention holds together and allows for the creation of a pad that can be cut to shape and wrapped around ½ inch PVC pipe to simulate use on curved body parts such as limbs. The less compression of the two components produces a lighter colored finished pad than darker rigid tablets that use higher compression pressures.

[0057] Flexible hemostatic pads may be compression molded into various shapes or machined into various shapes after molding. Machining can be performed with blades, dies, compressed air or lasers and can be used to score larger pads to cause them to break up into smaller shapes for application. Pads may be made in sheets individually or may be a continuous ribbon / roll of hemostatic pad material as any form of mechanical compression may be used. This allows the pads after compression to be stored and converted into finished products at a later date.

[0058] In another embodiment, there is a powder depth where the flexible hemostatic pad is no longer acceptable for cracking and delamination properties. The cracking or delamination properties were tested in the laboratory using the compression die / anvil method and scissors. The pads were further bent and rolled around a 1 / 2 inch PVC pipe. Small cracks are acceptable in the laboratory bend and cut test. Severe cracking and delamination when bending or cutting the formed flexible hemostatic pad is of more concern. Delamination is defined as when a portion of the compressed powder peels off from the backing material after bending or cutting. During testing, the use of powders with a height of 0.7mm and 2mm produced acceptable 50mm diameter flexible hemostatic pads. The use of a 4.3mm deep powder also produced pads, but a halo effect was observed where the outside of the tablet appears lighter than the inside due to the difference in compression force, as the powder on the outside of the pad is able to shift as the die is forced into the powder. The halo effect of the 4.3mm deep powder pad may have been overcome by using much longer fibers to prevent powder shifting during compression. Furthermore, flexible pads made with 4.3 mm deep powder cracked and peeled when bent and cut with scissors. Although the 4.3 mm deep powder product is still usable and effective in stopping bleeding, it may not be aesthetically acceptable in some markets. One skilled in the art can determine the maximum powder depth relative to fiber length to avoid undesirable levels of cracking and peeling.

[0059] Below is a photo of the product at 4.3mm depth. The product is still viable and effective, but suffers from some cosmetic defects after being wrapped around a 1 / 2" PCV pipe simulating a finger. This product would not experience cracking when wrapped around a human arm. [ka]

[0060] In another embodiment, a method for producing an optimally flexible hemostatic pad requires controlling the propensity to curl. The reason for curling is that the dry hemostatic compressed powder material absorbs moisture from the environment. This causes a difference in expansion between the top and bottom of the pad. The compressed powder expands as it gains more moisture, while the moisture-resistant velvety backing material maintains its shape, resulting in the device curling or bending towards the velvety backing material due to the longitudinal difference in expansion. One way to control curling propensity is to increase the depth of the powder initiation on the velvety material. For example, a pad made with a 2 mm deep powder will curl significantly less than one made with a 0.7 mm deep powder. Other methods for controlling curling propensity include starting with a powder that dries less easily, making geometric cuts in the hemostatic pad, or gluing multiple smaller pads to a tertiary substrate.

[0061] In yet another embodiment for controlling curl of the flexible hemostatic pad, the pad may be flattened after compression. If the powder contains less than about 20% moisture powder, the powder will absorb moisture from the surrounding atmosphere. The amount of absorption is based on the moisture level of the starting powder and the humidity of the air in which the powder is stored. For example, assume that a 20% moisture level is the equilibrium moisture (EM) of the powder. If the powder is compressed into the flexible hemostatic pad before reaching the EM or the EM balance changes, the resulting tablet will curl. This curl is the result of the powder being compressed in a fixed position and then expanding or contracting based on the change in moisture level to reach the EM. Powder that is not in the EM is compressed into the flexible hemostatic pad and then the pad is held flat to reach the EM. The flexible hemostatic pad resulting in the EM does not have a tendency to curl or the curl is not as severe as a pad that is not held in a fixed position during expansion.

[0062] This can lead to a manufacturing process where pads are made and then placed in an environment that promotes EM acquisition. These pads can be pre-cut or in sheets. This process allows rolls of intermediate product to be made and then cut to shape (final shape, or converting sheets) for "flattening" before packaging. If larger rolls of product are stored during manufacturing, the straightness and radius of the rolls are important to prevent cracking of the intermediate product.

[0063] In another embodiment, a pattern incorporating open spaces between the flexible pads can be used to prevent the flexible hemostatic pad from curling. This pattern allows the expanding compressed powder spaces to expand within and mitigate or reduce the tendency to curl. This pattern can be created, by way of one non-limiting example, during application of the powder to the velvet-like cloth, during compression using a patterned compression tool, by creating a pattern on the surface of the compressed powder after compression without damaging the velvet-like cloth backing, or by gluing separate strips or small tablets to the backing.

[0064] Another embodiment includes making the velvety material from a material that expands more freely longitudinally. Such a material should be a four-way stretch material. Examples include, but are not limited to, elastic, spandex, rubber, latex, neoprene, nitrile, vinyl, or blends of materials.

[0065] Another embodiment uses a velvety material that has sufficient stiffness to prevent curling or adhesion of the flexible pad to a more rigid substrate.

[0066] In another embodiment, the backing can be flocked into an irregular shape and the powder pressed directly onto the shape. The shape can be flexible or rigid, but the solid layer itself remains flexible. Such shapes include, for example, finger debridement cups, surgical gloves, hemostatic compression devices, hemostatic balloons, etc. This may require a compression tool to better fit the shape.

[0067] In another embodiment, the two components can be used to create a stronger, thinner flexible hemostatic pad. The thinner pad can be beneficial in the medical industry to conform around a vascular catheter line to lie nearly flat against the body and prevent "kinking" of the line. This type of product may require a more rigid support to improve application and prevent curling of the flexible pad.

[0068] In another embodiment, the flexible hemostatic pad can allow for manipulation around a patient's vascular catheter or other line or tubing using a simple slit and / or hole through the pad. The flexibility of the pad allows the slit to open and form a flap that seals the hemostatic agent around the line or tubing. This is not possible using traditional rigid tablets that must be designed in two halves with a complete hole through them.

[0069] In another embodiment, much larger flexible tourniquet pads can be manufactured. Such products may have advantages in military or EMS environments, or as floor coverings, against blood spills until they can be properly cleaned.

[0070] In another embodiment, the flexible hemostatic pad can be designed to allow localized tablet migration immediately after application. In this embodiment, when the flexible pad is applied to a wound, only the portion of the compressed powder in contact with the blood migrates from the velvety material and forms a seal on the wound. This migration can occur as soon as hemostasis is achieved. This ability of the pad contrasts with the rigid StatSeal® tablet of compressed powder. If migration occurs too quickly, tablet delamination will remove the seal and cause the wound to rebleed.

[0071] Typically, the hemostatic powder is applied in a uniform layer to a fibrous, velvety substrate and then compressed into the substrate with sufficient compressive force to create a unitary shape for the hemostatic pad as described below. [ka]

[0072] Uniform layers can be created by direct control dispersion, leveling mechanisms or vibration leveling. During each step of the lamination process, there may be a single layer or multiple layers that are uncompressed, partially compressed, or fully compressed. An example manufacturing flow chart is shown below: [ka]

[0073] In the process outlined above, the pre-height will be higher than the post-height for each component. The height of the fibers and hemostatic material will change as a result of compression, although the overall and relative heights of the fibers and powder may vary depending on the material and the desired removal effect. After compression, the fibers and hemostatic material are locked together.

[0074] The powder or multiple powder layers can be applied uniformly to the fibrous substrate to allow for even distribution of compression forces during the manufacturing process. Single or multiple pressure compression processes may be used. In multiple compression manufacturing processes, the compression forces of the previous compressions may be the same or different from the subsequent compressions.

[0075] A variety of compaction devices can be used, including, but not limited to, mechanical and hydraulic presses, or rolling presses utilizing compaction rollers.

[0076] The orientation of the material during production may be a backing at the bottom, then a powder layer, with compression from a die pressing downwards. Another method of production is to fill the cavity with powder to the appropriate depth, then apply a backing over the cavity / powder and compress the ingredients together. When applying powder to a flexible velvety material, it may prove difficult to form a uniform layer. Therefore, the second method may be preferred, as it may result in a more uniform powder layer. This second method may also be more conducive to continuous production using rolls of backing.

[0077] In manufacturing processes, it is often necessary to control or regulate the temperature of the tool. Controlling the temperature can help prevent pad formation or adhesion of either the contacting material to the tool.

[0078] The fiber length should be designed with the desired end product and its use in mind. For example, longer fiber lengths are typically desired for semi-flexible products and shorter fiber lengths are desired for more flexible products. Additionally, the fiber length and adhesive strength of the adhesive holding the fiber to the backing can have a correlated effect on the force required to remove the pad from the bleeding site and how much of the compressed powder remains at the bleeding site.

[0079] The following schematics are intended to illustrate the removal behavior of variously designed pads based on the manipulation of powder depth, fiber length, and fiber adhesion to the velvety substrate.

[0080] The products shown below are designed to leave a compressed powder layer on the wound, offering advantages over regular Rx or OTC use. [ka]

[0081] This product, shown below, is designed to remove most of the compacted powder when the pad is removed, leaving less powder behind in the wound. This can result in the wound rebleeding. This would be an advantage in military, EMT, triage type settings. [ka]

[0082] In another embodiment, the flexible hemostatic pad may use a double-sided velvety material compression product instead of a single-sided product. This makes application easier in limited lighting environments since both sides of the product are equally effective in stasis. A double-sided product may also help limit curling tendencies.

[0083] example In the first test, a thin layer of the hydrogen form of ground strong acid cationic resin was utilized at 19% moisture and spread onto a velvety material. Two pads were successfully made by compressing the hemostatic powder and fibrous backing to form a flexible hemostatic pad.

[0084] Additional testing revealed that pads made using backings with various fiber lengths and using various powder heights were acceptable in terms of flexibility and strength as shown below in Table 1. Note that "powder height" refers to the height of the powder before compression. [Table 1]

[0085] The products were also tested for hemostatic material stripping. All products were easily removed with the addition of water. All pads left a layer of powder on the wound after removal.

[0086] The pictures below show longer fibers with and without powder, which are woven into a textile material. [ka]

[0087] The pictures below show shorter fibers with and without powder. These fibers have been flocked / glued onto a woven material. [ka]

[0088] The photograph below shows a flexible hemostatic pad formed on / in a velvety backing. [ka]

[0089] Below are the results of compressing the powder into a velvety material at various pounds per square inch (psi). [Table 2]

[0090] Below is a picture of the curling effect of the pad using the dry powder. Ruler measurements are in millimeters. [Table 3]

[0091] Heat can be used to drive moisture from the polymer to reverse the curling effect. Below is a photo showing an example where a curled pad was heated in a small toaster oven to demonstrate the uncurling of the pad. [ka]

[0092] The flexible hemostatic pads demonstrated very strong hemostatic properties in in vitro testing, well above the human mean arterial pressure (MAP) of 70-100mmHg. Using various velvet backings in forming the flexible hemostatic pads, pressures ranging from at least 400mmHg to over 700mmHg, well above the MAP, were achieved. Hemostatic strength was tested with application of the pads to porcine blood. Pads were produced with a powder depth of 0.7mm to 2mm.

[0093] An acrylic block was used as the test fixture, with a horizontal hole drilled 1 / 4 inch halfway through the block and intersected by a 1 / 8 inch vertical hole from the surface to the 1 / 4 inch hole. EDTA stabilized porcine whole blood was applied around the 1 / 8 inch surface hole. A pad was then applied and held in place for 2 minutes. After 2 minutes, a syringe containing air was used to pressurize the system through the horizontal 1 / 4 inch inlet hole. The air pressure was recorded via data acquisition, with the end point being when the seal failed or the maximum output of the pressure transducer was reached. No mass was used to hold the pad in place during the air pressurization process. This test measured the burst strength of the blood / powder seal that was formed. Any additional mass on the pad would contribute to the hemostatic ability of the pad.

[0094] The results of tests using resins with various moisture levels (up to 20%), various velvety materials, and various powder heights before compression are shown below. All test samples retained pressure significantly above the MAP of 70-100mmHg. [ka]

[0095] In another example, the strength of removing the backing from a powder / blood seal formed between porcine blood and a flexible hemostatic pad was measured. The pulling force required to remove the pad from the simulated wound ranged from 0.1 kg to over 1.1 kg. In general, pads made from velvety backings with very short fibers were easily removed with a removal force of 0.1 kg, leaving the entirety of the compressed powder behind as the compressed powder separated from the velvety material. Pads made from velvety backings with long fibers required a much greater pulling force of over 1.1 kg. The units in the chart below are in kg. [ka] [Table 4]

[0096] There is concern that the fibers will interact with the wound during the healing process. If there is a full layer of compressed powder over the fibers (no exposed fibers), the mechanism of action of the resin-based hemostatic product to form a nearly instantaneous seal will not result in fiber contact with the wound. Therefore, there is no interference with healing. Upon removal of the backing, there may be visible fibers, but these fibers do not penetrate the depth of the powder to the wound. While not a medical concern, exposed fibers may present aesthetic issues and concerns to the end user.

[0097] In another embodiment, a sheet of the pad product can be made and then appropriately sized and shaped into the final product flexible pad that is cut from the sheet, as described below. [ka]

[0098] This can be done in a batch or continuous manner. For example, square shapes bonded to a flexible adhesive strip can be created to create a self-adhesive flexible bandage to stop bleeding. Examples of these cutting actions include, but are not limited to, scissoring, punch cutting, slicing, tearing, chopping, high velocity impact, laser cutting, and high pressure air cutting.

[0099] In another embodiment, the shape may be a section designed to fit around a medical line of tube that is inserted into the human body. [ka]

[0100] Examples of these cutting actions include, but are not limited to, a scissoring action, a punch cut action, a slicing action, a tearing action, a chopping action, a high velocity impact action, laser cutting, and high pressure air cutting. Below is a photo of a 1.5 inch die cut circular tablet. The edges are clean and there are no visible breaks. This cutting action is not possible with rigid compressed powder tablets. [ka]

[0101] Below are photos of example die cut designs. [ka]

[0102] Both are designed to fit around an indwelling vascular catheter. Note how the flexibility of the pads allows for a good fit around the catheter. These are flexible pads glued to a white foam cap.

[0103] In another test, tablets were made on a sheet of paper using similar conditions (50 mm die, 20k kg compression). Compared to paper, the leveling process of the powder on the velvety material was easier as the friction between the velvety material and the powder was increased, which prevented the powder from being dragged away and leaving powder-free areas on the backing. The resulting tablets (powder on paper) were more brittle and peeled off easily from the paper. The peeling was evident both when cutting the flexible pad structure and when wrapping it around a 1 / 2 inch PVC pipe. Below is a photo of the tablet after cutting and wrapping it around a 1 / 2 inch PVC pipe. The edges of the tablet cracked and peeled off from the paper backing. [ka]

[0104] Below are photographs of the longer and shorter fiber soft products removed from a piece of velvety material. [ka]

[0105] In the test above, several drops of whole bovine blood were applied to the unfinished side of a piece of leather. A flexible pad was placed on top of the blood and held in place for two minutes, then removed. The test on the left had a velvety material with longer fibers, leaving more fibers behind on top of the compressed powder left behind. The test on the right used a velvety material with shorter fibers, leaving fewer fibers behind.

[0106] Flexible hemostatic pads can be attached to a rigid or semi-rigid backing. An example of such a product is a flexible pad glued to a rod-shaped device to produce an applicator to stop a nosebleed. Another example is a flexible pad attached to a hard foam material to allow for treatment around vascular catheter lines, yet still maintain a very thin profile. Another example is a hand-held plastic compression device that applies pressure to the groin area to stop hemostasis after arterial catheter placement. Another example is a dental application after tooth extraction.

[0107] In another example, 2% cross-linked gel ion exchange resin gained approximately 20% moisture when left exposed to room temperature conditions in ambient air conditions. A flexible pad was made with the dry resin and the pad was placed on a piece of wood. A flat weight was placed on top of the pad. After 3 days, the resulting pad was at near equilibrium moisture with the room and did not curl when the weight was removed. As the resin absorbed moisture, it was able to expand under the weight, but the hemostatic pad did not curl.

[0108] In another example, a drop of blood was applied to a leather strip and a hemostatic compressed powder pad was applied to hold it in place. The area of ​​the compressed powder was much larger than the area of ​​the blood drop. The entire flexible hemostatic pad was expected to move from the velvety material, but only the portion in contact with the blood separated. This unexpected result of the flexible hemostatic pad allows the pad to be adhered to the compression device and removed as desired after hemostasis without causing rebleeding.

[0109] Compression devices that can be used to apply pressure to the wound include circumferential, mechanical, pneumatic, or hydraulic devices, tourniquet-like devices, or standard military compression bandages, which also allow the flexible tourniquet pad to be applied to any wound bandage.

[0110] Additional examples relate to pad thicknesses ranging from 20 to 30 microns, including, but not limited to, pads that are 25 microns thick.

[0111] Other examples include the following:

[0112] A flexible hemostatic pad device comprising: a hemostatic powder compressed into a velvety backing at a minimum of 7,244 psi; a powder comprised primarily of a hydrophilic polymer; a velvety material having a flexible surface and fibers extending perpendicularly from the backing; a fiber length of less than 5 mm; a powder layer prior to compression that is greater than the fiber length; and a resulting compressed product of 3 mm or less, wherein the polymer is an ion exchange resin.

[0113] A semi-flexible hemostatic pad device comprising: a powder compressed into a velvety material at a minimum of 7,244 psi; a powder comprised primarily of a hydrophilic polymer; a velvety material having a flexible surface and fibers extending perpendicularly from a backing; a layer of powder prior to compression that is greater than the fiber length; and a resulting compressed product of 3 mm or greater, wherein the polymer is an ion exchange resin.

[0114] A pad designed to remove a majority of the product when removed from a bleeding patient or soldier for triage, the pad comprising: a powder compressed into a velvety material at a minimum of 7,244 psi; a powder comprised primarily of a hydrophilic polymer; a velvety material having a flexible surface and fibers extending perpendicularly from a backing; a velvety material having fibers with an adhesion strength of the fibers greater than the adhesion strength of the pad to the wound; a layer of powder prior to compression having a height equal to or less than the length of the fibers; a resulting compressed product less than 10 mm; the resulting compressed product leaving less than 25% of the original hydrophilic powder on the wound upon removal of the product from the wound to facilitate wound cleansing, the polymer being an ion exchange resin.

[0115] A hemostatic pad having an irregular shape or hard surface, comprising: a powder compressed into a substrate at a minimum of 7,244 psi; a powder comprised primarily of a hydrophilic polymer; an irregularly shaped substrate having a surface with vertically extending fibers; and a layer of pre-compressed powder having a height equal to or greater than the length of the fibers, wherein the compression apparatus is designed to conform to the irregular shape of the device to be converted into a hemostatic device, and wherein the polymer is an ion exchange resin.

[0116] A bi-layer or multi-layer pad pressing comprising: a powder pressed into a substrate; a powder composed primarily of a hydrophilic polymer; a substrate consisting of a surface having vertically extending fibers; an initial layer of powder before pressing that is integrally mixed with the fibers; an additional layer of the same or different powder applied before or after an initial pressing force to press the fibers and powder together with the extending fibers onto the pressed powder; a final pressing force of at least 7,244 psi to produce a final product, wherein the polymer is an ion exchange resin.

[0117] A die cut hemostatic pad comprising a sheet or roll of powder compressed into a velvet-like material which is cut into a usable shape; powder compressed into the velvet-like material at a minimum of 7,244 psi; powder comprised primarily of a hydrophilic polymer; velvet-like material having a flexible surface and vertically extending fibers; fiber length less than 5 mm; a pre-compressed powder layer greater than the fiber length, said polymer being an ion exchange resin.

[0118] A fixation, compression, or adhesive device comprising a cover for attaching a flexible pad to a compression device or adhesive strip, the cover being designed to hold the hemostatic pad in contact with a bleeding wound; a powder compressed into a velvety material at a minimum of 7,244 psi to form a flexible hemostatic pad; a flexible hemostatic pad shaped to fit the fixation device or compression device; a hemostatic pad attached to the fixation device or compression device; a powder composed primarily of a hydrophilic polymer; a velvety material having a flexible surface and fibers extending perpendicularly from the backing; a fiber length of less than 5 mm; and a pre-compressed powder layer of a height comparable to the fiber length (within 3 mm), the polymer being an ion exchange resin.

[0119] A cover for attaching a flexible pad to a rigid or semi-rigid surface, comprising: a rigid or semi-rigid carrier; a powder compressed into a velvety material at a minimum of 7,244 psi to form a flexible hemostatic pad; a flexible hemostatic pad shaped to conform to the rigid or semi-rigid carrier; a hemostatic pad attached to the rigid or semi-rigid carrier; a powder composed primarily of a hydrophilic polymer; a flexible surface, a velvety material having fibers extending perpendicularly from a backing; a fiber length of less than 5 mm; and a pre-compressed powder layer of a height comparable to the fiber length (within 3 mm), wherein the polymer is an ion exchange resin.

[0120] A flexible hemostatic pad package packaged in a moisture-regulating package to prevent curling, comprising: a hemostatic powder compressed into a velvety backing at a minimum of 7,244 psi; a powder comprised primarily of a hydrophilic polymer; a velvety material having a flexible surface and fibers extending perpendicularly from the backing; said flexible hemostatic pad package within a moisture barrier comprising a primary package to prevent curling, said polymer being an ion exchange resin.

[0121] A flexible hemostatic pad device comprising: a hemostatic powder compressed into a velvety backing at a minimum of 7,244 psi; a powder comprised primarily of a hydrophilic polymer; a velvety material having a flexible surface and fibers extending perpendicularly from the backing; said velvety material comprised of a four-way stretch material; a fiber length less than 5 mm; a powder layer prior to compression greater than the fiber length; and a resulting compressed product of 3 mm or less, wherein said polymer is an ion exchange resin.

[0122] A double sided flexible hemostatic pad comprising: a powder compressed into a velvety material at a minimum of 7,244 psi to form a flexible hemostatic pad; a powder comprised primarily of a hydrophilic polymer; a velvety material having a flexible surface and fibers extending perpendicularly from a backing; a fiber length less than 5 mm; a layer of powder before compression of a height comparable to the fiber length; and a resulting compressed product less than 5 mm, wherein the polymer is an ion exchange resin, the double sided flexible hemostatic pad being made either by gluing two single sided pads together, by folding a single pad upon itself, or by using a double sided velvety fiber that holds the compressed powder on both sides of a relatively flat pad.

[0123] A flexible hemostatic pad device that maintains flatness while reaching moisture equilibrium, comprising: a hemostatic powder compressed into a velvety backing at a minimum of 7,244 psi; a powder comprised primarily of a hydrophilic polymer; a velvety material having a flexible surface and fibers extending perpendicularly from the backing; a fiber length of less than 5 mm; a powder layer prior to compression that is greater than the fiber length; and a resulting compressed product of 3 mm or less, wherein the polymer is an ion exchange resin, and the flexible hemostatic pad is capable of reaching moisture equilibrium depending on the environment, but remains flat after final compression during manufacture, resulting in a product that has less tendency to curl when exposed to the atmosphere.

[0124] A flexible hemostatic pad containing additional materials, comprising: a hemostatic powder compressed into a velvety backing at a minimum of 7,244 psi; a powder composed primarily of a hydrophilic polymer; a powder containing additional ingredients; a velvety material having a flexible surface and fibers extending perpendicularly from the backing; a fiber length less than 5 mm; a powder layer before compression greater than the fiber length; and a resulting compressed product of 3 mm or less, wherein the polymer is an ion exchange resin, and the additional ingredients may consist of, but are not limited to, a solid flocculant for flocculating blood solids, a solid antimicrobial agent, a solid antibacterial agent, a liquid antimicrobial or antibacterial agent absorbed into the polymer, a manufacturing processing aid, a colorant, or a combination of such materials.

[0125] All references cited herein, including, but not limited to, all articles, publications, patents, patent applications, provisional patent applications, presentations, texts, reports, manuscripts, pamphlets, books, internet posts, journal articles, and / or periodicals, are incorporated herein by reference in their entirety, including all figures and tables, unless they contradict the explicit teachings of this specification. The discussion of references herein is intended merely to summarize the assertions made by their authors and is not an admission that any reference constitutes prior art. Applicants reserve the right to challenge the accuracy and pertinence of the cited references.

Claims

1. 1. A flexible hemostatic pad, comprising: a velvety base material and a hemostatic powder compressed into the velvety base material, the compressed hemostatic powder maintaining flexibility; A flexible hemostatic pad, wherein said hemostatic powder comprises an insoluble cation exchange material.

2. 10. The flexible hemostatic pad of claim 1, wherein said hemostatic powder is compressed into said velvety substrate with a compressive force of between 7,244 and 10,000 psi.

3. The flexible hemostatic pad of claim 2, wherein said compressive force is between 7,500 and 10,000 psi.

4. 3. The flexible hemostatic pad of claim 2, wherein said compressive force is 7,500 psi.

5. 3. The flexible hemostatic pad of claim 2, wherein said compressive force is 7,244 psi.

6. 10. The flexible hemostatic pad of claim 1, wherein said hemostatic powder is compressed into said velvety substrate with a compressive force of 6,000 to 8,000 psi.

7. 10. The flexible hemostatic pad of claim 1, wherein the fibers of said velvety substrate are compressed a minimum of 2 mm.

8. 10. The flexible hemostatic pad of claim 1, wherein the hemostatic powder further comprises a ferrate salt.

9. 9. The flexible hemostatic pad of claim 8, wherein said ferrate is potassium ferrate.

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