Suspension comprising fibrinogen, thrombin and alcohol, a method for preparing such a suspension, a method for coating a carrier with such a suspension, a method of drying a coating of a carrier, and a coated collagen sponge

A method of preparing a suspension with fibrinogen and thrombin, comprising:

• providing a fibrinogen mixture of fibrinogen and an alcohol,
• providing a thrombin mixture of thrombin and an alcohol,
• mixing the fibrinogen mixture and the thrombin mixture, so as to obtain said suspension,
• so as to obtain a suspension containing fibrinogen and thrombin particles, the Folk Ward mean diameter of the particles being 25-100 μm.

A method for coating a carrier with a suspension comprising fibrinogen and thrombin, wherein the suspension has been derived from a method comprising the steps of:

• providing a fibrinogen mixture of fibrinogen and an alcohol,
• providing a thrombin mixture of thrombin and an alcohol,
• mixing the fibrinogen mixture and the thrombin mixture, so as to obtain said suspension,
• so as to obtain a suspension containing fibrinogen and thrombin particles, the Folk Ward means diameter of the particles being 25-100 μm, the method of coating comprising:
• providing the suspension of fibrinogen, thrombin and an alcohol at a location near the carrier,
• applying said suspension to a coating surface of the carrier.

A coated collagen sponge with a coating of fibrinogen and thrombin, wherein the coated collagen sponge has been obtained by a method comprising the steps of:

• providing a collagen sponge by a method comprising:
• preparing a collagen gel,
• mixing air into the collagen gel, so as to obtain a collagen foam,
• drying the collagen foam, so as to obtain a dry block of collagen sponge having chambers therein,
• isolating, from the block of collagen sponge, parts of sponge showing at least one of:
• a chamber diameter of more than 0.75 mm and less than 4 mm, and
• a chamber with an average diagonal dimension of 3 mm,
• applying a suspension of fibrinogen, thrombin and an alcohol to a coating surface of the collagen sponge, and
• submitting the coated carrier to a pressure below 1000 mbar, so as to obtain a dried coating surface on the carrier, so as to fixate the dried coating to the coating surface,
• the coated collagen sponge having at least one of the following properties:
• the suspension is distributed evenly over a given width of the coating surface, so that the mass of fibrinogen per area unit of the coating surface varies at most 25%,
• the abrasion of the coating is less than 2.0 mg/cm2 when a sample of 1×5 cm2 of the coated material is shaken in a test-tube on a Vibrofix shaker at a frequency of 800-1200 rpm for 2 minutes.