Drug – bio-affecting and body treating compositions – Preparations characterized by special physical form – Web – sheet or filament bases; compositions of bandages; or...
Patent
1989-11-09
1991-11-12
Page, Thurman K.
Drug, bio-affecting and body treating compositions
Preparations characterized by special physical form
Web, sheet or filament bases; compositions of bandages; or...
424 81, 424487, 514944, A61L 1500, A61K 3736
Patent
active
050646524
DESCRIPTION:
BRIEF SUMMARY
The present invention relates to a package comprising a wound dressing packed in a sterile container, and a process for producing sterile packages of this type.
U.S. Pat. No. 3,428,043 describes a bandage of water-swellable hydrophilic polymer with a co-extensive fabric reinforcement, that is supplied dry and contains therapeutically active ingredients. There is no disclosure of any process of sterilisation of the bandage. One problem with the product described is that it is brittle when it is dry so that even with the reinforcement the polymer foil may crack and become discontinous. The reinforcement, necessary because the gel is insufficiently strong when swollen, renders the bandage opaque preventing observation of the underlying wound. Furthermore the most serious problem is that to be used wet the bandage has to be swollen before application to the wound which is inconvenient for the nurse or doctor. The incorporation of fabric reinforcement during manufacture is inconvenient.
U.S. Pat. No. 3,520,949 describes a water-free polymerisation to make water-swellable hydrophilic articles for various uses. It is stated that the articles themselves can be sterilised by boiling. One of the uses is as a bandage reinforced with Dacron fabric and containing medication for slow release to a wound. The bandage is presented in its dry form and must be pre-swollen before use. This bandage has all the disadvantages of that described in U.S. Pat. No. 3,428,403. Although sterilisation by boiling is possible for small articles which are fairly sturdy, it is liable to cause damage to thin sheet materials. Sheets are particularly difficult to handle when they are large.
In U.S. Pat. No. 3,419,006 cross-linked poly(alkylene glycol) gels are used as wound dressings. The polymer is highly swellable, and a gel swollen with pure water may contain about 1-20% polymer. The gels may be autoclaved in a petri dish apparently containing water, the dish being sealed in a plastic bag. According to the description the gel appears to be chopped in a blender with the water and the dispersion autoclaved after bubbling with nitrogen. The gel sheets are insufficiently strong to be used unsupported and in practice must always be strengthened by embedded mesh or gauze and often also a polymeric sheet backing.
In DE-A-2725261 a transparent sheet of a hydrophilic polymer gel is swollen with water and, usually, therapeutically active substances. All the products exemplified are made by polymerisation of water-soluble ethylenically unsaturated monomer in the presence of a gellable high molecular weight substance, e.g. a carbohydrate or a protein. The swollen dressings can be supplied packed in pouches of, e.g. metal or plastics foil, in its swollen condition. It is stated that the packed bandages should be sterile but there is no disclosure of how this is achieved.
In a patent of addition, DE-A-2849570 and U.S. Pat. No. 4,556,056 the gels are dried before storage. When presented in this form the material has the problems discussed above.
In a further improvement of the product described in DE2849570 the polymer is provided in dry powder form as described in U.S. Pat. No. 4,554,156. The powder may be applied direct to a wound or is applied mixed with a little water to form a paste. It is stated that the paste may be supplied in a sterile syringe but there is no disclosure as to how sterility is achieved. According to the specification, on use the particles join to form a coherent film. One of the reasons that the polymer is provided in particle form is that this makes removal of excess monomer from the polymer product easier. Use of this product is highly inconvenient, application of a powder is inconvenient, premixing of the powder with the water is also an undesirable extra step for a nurse or a doctor and application of a paste from a syringe can be messy. All the methods make it difficult or impossible to provide a smooth film of uniform thickness for optimum healing. Furthermore particulate mixtures may not always form a coherent film and any
REFERENCES:
patent: Re27401 (1972-06-01), Wichterle et al.
patent: 3419006 (1968-12-01), King
patent: 3963685 (1976-06-01), Abrahams
patent: 4060678 (1977-11-01), Steckler
patent: 4267295 (1981-05-01), Gallop et al.
patent: 4857334 (1989-08-01), Korol et al.
Page Thurman K.
Webman E. J.
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