GB2357435A

GB2357435A - Absorbent medicinal articles

Info

Publication number: GB2357435A
Application number: GB9930563A
Authority: GB
Inventors: Deborah Addison
Original assignee: Johnson and Johnson Medical Ltd
Current assignee: Johnson and Johnson Medical Ltd
Priority date: 1999-12-23
Filing date: 1999-12-23
Publication date: 2001-06-27
Also published as: GB9930563D0; AU5442401A; WO2001047459A1

Abstract

The invention provides medicinal articles comprising a plurality of elongate absorbent flexible filaments 2 radiating from a core region. Preferably, at least 50 filaments radiate from the core region in angularly offset planes to provide space filling as well as absorbency. The invention also provides the use of such articles for the treatment of deep wounds and for soft tissue cavity filling.

Description

2357435 ABSORBENT MEDICINAL ARTICLES The present invention relates to

absorbent medicinal articles, and to the use thereof for the treatment of deep wounds.

There is a need in clinical practice for absorbent wound dressings that can be inserted into deep wounds to absorb wound exudate and provide cavity filling. Such dressings should be highly absorbent, conformable to the shape of the wound, and inexpensive.

There is also a need in clinical practice for soft tissue cavity filling. The materials used for such fillings should preferably be highly conformable and biocompatible. Furthermore, such soft tissue filling materials may be bioresorbable, whereby the cavities are filled by new soft tissue over a period of time by natural healing processes.

It is known to provide textile or foam-based absorbent structures for dressing deep wounds. Those structures are insufficiently conformable to fit every deep wound, unless they are cut into shape. Furthermore, such absorbent structures can be relatively difficult to remove from a deep wound after use without causing further trauma. US-A-4837285 describes the use for soft tissue cavity filling of resorbable collagen sponge beads having diameters of from 0.1 to 4.0 mm. The beads have 25 pore sizes of from 50 to 350 micrometers. Such beads can be difficult to handle, and are not suitable for use as a removable, absorbent dressing for deep wounds. DE-A-4037931 describes a deep wound dressing structure consisting of a cavity filling plug of resorbable collagen foam containing an array of hollow resorbable filaments. The filaments are bundled together at one end, and connected to a drain for wound fluid, whereby the wound fluid is continuously drained from the wound cavity through the hollow filaments. Such a structure is 2 relatively expensive to construct, and insufficiently conformable to a wide range of wound cavity shapes.

Accordingly, it is objective of the present invention to provide a highly 5 conformable absorbent dressing for a deep wound.

It is a further object of the present invention to provide such a dressing for a deep wound that is inexpensive and simple to construct.

It is a further object of the present invention to provide such a dressing for the deep wound that is easy to remove after use.

It is a further object of the present invention to provide structures for soft tissue cavity filling that are highly conformable, inexpensive and may be bioabsorbable.

The present invention provides a medicinal article comprising a plurality of elongate absorbent flexible filaments radiating from a core region.

Preferably, at least ten filaments radiate from the core region, more preferably at least 50 such filaments and still more preferably at least 100 such filaments.

Preferably, the filaments radiate from the core region in plural angularly offset planes. This provides the article with space filling properties in addition to absorbency.

The filaments should be flexible to provide the article with excellent conformability. The filaments should be absorbent, that is to say they are hydrophilic and can absorb a substantial amount of physiological saline at ambient temperature. Finally, the filaments should be biologically compatible in vivo. That is to say, the filaments should be non-toxic, non-antigenic and not shed particles 3 into the wound. Preferably, the filaments are formed from microporous sponge materials, textile fibres, or hollow tubes.

Suitable materials for the manufacture of the filaments include hydrophilic polyurethane foams such as those described in EP-A-0541391. Other suitable materials include textile threads made up of multiple hydrophilic textile fibers such as viscose, and filaments of insoluble alginates such as calcium alginate.

Preferably, short (staple) textile fibers are avoided because they may shed from the article into the wound. The textile filaments may be melt bonded to increase their integrity in use. The filaments may be coated with a hydrogel or other hydrophilic and wound-compatible coating.

In certain preferred embodiments, the filaments may be bioabsorbable in vivo. Such filaments include collagen filaments, spun polylactidelpolyglycolide filaments, and filaments of oxidised regenerated cellulose (ORC). For example, threads of ORC formed by oxidation of viscose rayon threads with dinitrogen tetroxide may be used.

Preferably, the flexible filaments are free to flex outside the core region.

That is to say, the filaments are not tied or embedded in a matrix outside the core region. This allows the filaments to bend freely to assume the shape of any cavity into which the article is inserted. It also enables the threads to swell as necessary to absorb wound fluid. It also makes it easy to remove the article once it is saturated with wound fluid, by grasping a free end of any thread. Furthermore, the article is adaptable to any size of wound cavity, since is straightforward to insert and remove more than one article into larger cavities.

Preferably, the filaments radiate a distance of 1 mm to 50mm from the core. More preferably, substantially all of the filaments radiate a substantially equal distance from the core, whereby the article has a substantially spherical appearance in the absence of external forces. Preferably, the the dry crosssectional are of said filaments is in the range of from 0.1 to 4MM2, and more preferably it is in the range of from 0.2 to 1.00 MM2. Preferably, the ratio of length 4 to maximum diameter of the filaments outside the core is in the range of from 10: 1 to 100:1. Preferably, the filaments have a liquid absorbency for pysiological saline of at least 2 g/g at 37 C, more preferably at least 5 glg.

Preferably, the core has a maximum dimension of from 2 to 20mm. Preferably, the core comprises a bundle or knot of the filaments that radiate therefrom.

In certain preferred embodiments the core region comprises a reservoir of 10 therapeutic, absorbent or superabsorbent material.

Preferably, the medicinal article according to the present invention is sterile, and preferably it is packaged in a microorganism-impermeable container.

Preferably, the medicinal article according to the present invention further comprises a therapeutic substance selected from the group consisting of antiseptics, antibiotics, hormones, analgesics, growth factors, antifungal agents or spermicidal agents.

It will be appreciated that the medicinal articles according to the present invention have many uses, not only for soft tissue cavity filling and treatment of deep wounds, but also for insertion into and removal from other body cavithes such as the mouth, gastrointestinal tract and vagina for therapeutic and prophylactic purposes.

Preferably, the medicinal articles according to the present invention are suitable for use as a wound dressing for a deep wound, or for filling soft tissue cavities.

Accordingly, the present invention further provides a medicinal article according to the present invention for the preparation of a medicament for use in the treatment of wounds.

Particular embodiments of the invention will now be described further, by way of example, with reference to the accompanying drawings, in which:

Figure -1 shows a side view (from any direction) of an absorbent medicinal 5 article according to the present invention; Figure 2(a)-(b) shows schematic perspective views of steps in one method for the manufacture of an article according to the present invention; and Figure 3(a)-(c) shows schematic longitudinal cross-sectional views of steps in a second method of making a article according to the present invention.

Referring to Figure 1, the article 1 is formed with a large number of elongate, highly flexible (floppy) textile filaments 2 radiating from a central core (not visible in the drawing). The filaments 2 are formed from non-staple viscose rayon textile fibers of the type used in N-A textile wound dressings supplied by Johnson & Johnson Medical Ltd. The textile filaments have a dry basis weight of about 1 g/m and an uncompressed diameter of about 1 mm.

The overall appearance of the article 1 is generally spherical, but its conformability is such that it tends to collapse slightly under its own weight, for example when resting on a flat surface. The article 1 resembles a floppy elastomeric catching toy of the kind described for example in EP-A- 0295114, but differs therefrom in that the filaments are absorbent and compatible with deep wounds. Furthermore, the dimensions of the article according to the present invention are generally smaller, typically in the overall diameter range 1-5cm. The filaments 2 are preferably not elastomeric.

The core of the article has a relatively small diameter compared to the overall diameter of the article. The core is made up of a bundle or knot of the filaments bound together by a knot, suture or tie.

6 The article 1 may be made by the process described in EP-A-0295114 and shown schematically in Figure 2. Briefly, three continuous lengths of the absorbent textile filaments are each wound in a pattern of reverse bend loops, and are then stretched as loops. Three such loops 5,6,7 are then stretched orthogonally as shown in Figure 2(a). A nylon tie 8 is used to secure the loops together as shown schematically in Figure 2(b), and the six ends of the loops 5,6,7 are then cut, and the loops released to form the article 1.

An alternative method of forming the article 1 is shown in Figure 3. The process starts with two annular sheets of card 9,10 placed in face to face relationship. A continuous long filament of the textile is wound around the annulus in toroidal fashion as shown in section in Figure 3(b). The outer half of the resulting torus 11 of wound filaments is cut circumferentially along the line AA shown in Figure 3(b). A nylon suture or the like 12 is then wound around the bundle of filaments by insertion between the sheets of card, and knotted tightly to produce the structure shown in section in Figure 3(c). The sheets of card 9,10 are then cut away to leave the article as shown in Figure 1.

The above embodiments have been described by way of example only.

Many other embodiments failing with the scope of the accompanying claims will be apparent to the skilled reader.

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Claims

1 A medicinal article comprising a plurality of elongate absorbent flexible filaments radiating from a core region.

2. A medicinal article according to claim 1, wherein at least ten of said filaments radiate from said core region.

3. A medicinal article according to claim 2, wherein at least 50 of said 10 filaments radiate from said core region.

4. A medicinal article according to claim 3, wherein at least 100 of said filaments radiate from said core region.

5. A medicinal article according to any preceding claim, wherein said filaments radiate from said core region in plural angularly offset planes.

6. A medicinal article according to any preceding claim, wherein said filaments comprise hydrophilic sponge materials, multifiber textile threads, or hollow tubes.

7. A medicinal article according to any preceding claim, wherein said filaments comprise a polyurethane, hydrophilic textile fibers, an alginate, or a bioabsorbable polymer.

8. A medicinal article according to any preceding claim, wherein said filaments comprise collagen, polytactidelpolyglycolide, or oxidised regenerated cellulose.

9. A medicinal article according to any preceding claim, wherein said core region comprises a reservoir of absorbent or superabsorbent material.

10. A medicinal article according to any preceding claim, where is sterile and packaged in a microorganism-impermeable container.

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11. A medicinal article according to any preceding claim, wherein the dry uncompressed cross-sectional area of said filaments is in the range of from 0.1 to 4MM2.

12. A medicinal article material according to claim 11, wherein the dry uncompressed cross-sectional area of said filaments is in the range of from 0.2 to 1.00 MM2.

13. A medicinal article according to any preceding claim, wherein the ratio of length to maximum uncompressed diameter of said filaments is in the range of from 10: 1 to 100: 1.

14. A medicinal article for medical use according to any preceding claim, wherein substantially all of said filaments radiate a substantially equal distance from said core in the absence of external forces.

15. A medicinal article according to any preceding claim, wherein said filaments comprise a hydrogel.

16. A medicinal article according to any preceding claim, wherein the filaments radiate a distance of 1 mm to 50mm from said core.

17. A medicinal article according to any preceding claim, wherein the core has a maximum dimension of from 2 to 20mm.

18. A medicinal article according to any preceding claim, wherein the core comprises a bundle or knot of the filaments radiating therefrom.

19. A medicinal article according to any preceding claim, wherein the liquid absorbency of the filaments for physiological saline at 370C is at least 2g/g.

20. A medicinal article according to any preceding claim, wherein the filaments are free to flex outside said core region.

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21. A medicinal article according to any preceding claim, further comprising a therapeutic substance selected from the group consisting of antiseptics, antibiotics, hormones, analgesics, growth factors, antifungal agents or spermicidal 5 agents.

22. A medicinal article according to any preceding claim for use as a wound dressing for a deep wound.

23. A medicinal article according to any one of claims 1 to 21 for use as in soft tissue cavity filling.

24. Use of a medicinal article according to any one of claims 1 to 21 for the preparation of a medicament for use in the treatment of deep wounds. 15

25. Use of a medicinal article according to any one of claims 1 to 21 for the preparation of a medicament for use in soft tissue cavity filling.

26. Use according to claim 24 of 25, wherein the article is fully bioresorbable in 20 the mammalian body.