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AssigneesCeskoslovenska akademie ved of Praha, Akademie der Wissenschaften der DDR
InventorsFritz Loth, Horst Dautzenberg, Jiri Stamberg, Jan Peska, Dieter Bertram, Herbert Lettau
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The invention pertains to the absorbing dressing for wounds, which consists of spherical particles of regenerated cellulose of the size 0.05-0.5 mm (preferably 0.05-0.3 mm) and a macroporous structure characterized by the cyclohexane regain of the dry material at least 0.2 ml/g. The dressing is prepared from the regenerated cellulose swollen with water by replacement with organic solvents and the subsequent drying of the product swollen with the said solvent. The porous structure of the dressing warrants that it can absorb excretions of the wound in the amount 1.5 to 5 g water per g of solids; the grainy macrostructure remains preserved during the absorption so that the material applied on the wound in the form of a powder in the layer 2-5 mm thick, in particular 2-3 mm thick, can be without difficulties and almost without pain rinsed away with water.
A powder dressing for wounds comprising spherical particles of water swollen regenerated cellulose beads wherein the water had first been replaced by an organic solvent, the solvent sequentially removed and the beads dried, said particles having a diameter of between 0.05 to 0.5 mm and a macroporous structure characterized by a porosity in the dry state corresponding to the cyclohexane regain of at least 0.2 ml/g of the dry material.
A method for forming a powder dressing for wounds which consists of the sequence of steps of water swelling a mass of regenerated cellulose beads, contacting said water swollen beads with one of an organic solvent solution selected from the group consisting of (a) a water miscible, (b) a partly water miscible, or (c) a mixture of a water miscible and a water immisible organic solvent, and capable of absorbing at least 5% water to form a mixture of solvent and water, removing the water from said mixture until all the water in said mixture and said beads is replaced with solvent and said solvent maintains said beads swollen, removing said solvent and drying said beads, and separating from said dried beads those particles having a diameter of at least 0.05 mm and a macroporous structure characterized by a porosity in the dry state corresponding to the cyclohexane regain of at least 0.2 ml/g of the dry material.
Dependencies are inferred from the claim text.