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Factor VIII Concentrate; Antihemophilic Factor; Dried Human Antihemophilic Fraction; Human Coagulation Factor VIII.

Category Human blood and blood products (coagulant; antihemorrhagic agent).

          Dried Factor VIII Fraction is a freeze-dried plasma protein fraction that contains the glycoprotein coagulation factor VIII together with varying amount of von Willebrand factor, depending on the method of preparation. It is obtained from human plasma that complies with the requirements stated under Plasma for Fractionation, p. 193. Auxiliary substances such as a stabilizer may be added. It contains no antimicrobial preservative.

          The specific activity is not less than 1 IU of factor VIII:C per mg of total protein before the addition of any protein stabilizer. The potency of the preparation, reconstituted as stated on the label, is not less than 20 IU¹ of factor VIII:C per ml.

Description White or pale yellow powder or friable solid.

Strengths available 250, 500, 1000, and 1500 IU.

Dose Intravenous infusion, as prescribed by the physician. The dosage of factor VIII should be determined for each patient and will vary with the circumstances involving bleeding or type of surgery.

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¹ The potency of Antihemophilic Factor (Factor VIII) is expressed in terms of antihemophilic factor units (AFU) or International Units (IU) of antihemophilic activity. One AFU is equivalent to one IU as defined by the World Health Organization Standard for Blood Coagulation Factor VIII, human, and is approximately equal to that quantity of antihemophilic factor present in 1 ml of fresh pooled human plasma. Since the activity standard is not a specifically defined value, the actual factor concentration per unit may vary. 

Warning

1. Fever, chills, urticaria, stinging at the infusion site, and mild allergic reactions may occur.

2. Hypersensitivity, allergic reactions, severe anaphylaxis (including shock) may occur.

Expiration date When stored under the prescribed condition, the expiration date is not later than 2 years from the date of the last satisfactory test for potency.

Packaging and storage Dried Factor VIII Fraction shall be kept in tightly closed containers, protected from light and stored at a temperature of 2º to 8º.

Labelling Complies with the “General Information for Biological Products”, p. 177. In addition, the label on the container states (1) the number of IU of factor VIII:C in the container; (2) the concentration of protein in g per litre of the solution constituted as directed; (3) the maximum fibrinogen content; (4) the name and amount of any added substance; (5) the name and volume of solvent to be used for reconstitution; (6) that if solution is not complete or if a gel forms on reconstitution, the preparation shall not be used; (7) that the solution should be used as soon as possible and in any case within a stated time, not exceeding 3 hours, of constitution and any unused solution discarded; (8) whether the preparation is suitable for the treatment of von Willebrand’s disease; (9) that a filter is to be used in the administration set.

Before carrying out the identification, the tests (except those for constituted solution and water) and the assay, immediately reconstitute the   preparation to be examined as stated on the label.​

 

Identification

          A. Using an antiserum specific to human plasma proteins and a range of antisera specific to the plasma proteins of each species of domestic animal commonly used in the preparation of materials of biological origin, carry out precipitation tests on the preparation being examined. The preparation contains proteins of human origin and gives negative results with antisera specific to plasma proteins of the other species.

          B. The assay for factor VIII:C contributes to the identification of the preparation.

pH 6.5 to 7.5 (Appendix 4.11).

Osmolality Not less than 240 mOsmol/kg (Appendix 4.35).

Solubility test Reconstitute the solution as stated on the label. The preparation dissolves completely under gentle swirling within 10 minutes, giving a clear or slightly opalescent, colourless or slightly yellow solution.

Water Not more than 3.0 per cent w/w (Karl Fischer Method, Appendix 4.12). Add a suitable volume of anhydrous methanol to the container of the preparation to be examined, shake, allow to stand and carry out the determination on a known volume of the supernatant liquid.

Total protein (Note For some products, especially those without a protein stabilizer such as albumin, this method may not be applicable and another validated method for protein determination must therefore be performed.) If necessary, dilute the solution with saline TS to produce a solution containing about 15 mg of protein in 2 ml. To 2.0 ml of the resulting solution in a round-bottomed centrifuge tube add 2 ml of a 7.5 per cent w/v solution of sodium molybdate and 2 ml of a solution containing 1 volume of nitrogen-free sulfuric acid in 30 volumes of water. Shake, centrifuge for 5 minutes, decant the supernatant liquid, and allow the inverted tube to drain on filter paper. Using the residue thus obtained carry out the determination as described in the “Determination of Nitrogen” (Method II, Appendix 6.7), calculate the content of protein by multiplying the result by 6.25.

Hemagglutinins, anti-A and anti-B Dilute the constituted solution with saline TS to produce a solution containing 3 IU of factor VIII:C per ml. Carry out the test for hemagglutinins, anti-A and anti-B using a suitable indirect method such as that described below.

The 1 in 64 dilutions do not show agglutination.

          Prepare in duplicates serial dilutions of the preparation being examined in saline TS. To each dilution of one series add an equal volume of a 5 per cent v/v suspension of group A₁ red blood cells previously washed three times with saline TS. To each dilution of the other series add an equal volume of a 5 per cent v/v suspension of group B red blood cells previously washed three times with saline TS. Incubate the suspensions at 37º for 30 minutes and then wash the cells three times with saline TS. Leave the cells in contact with a polyvalent anti-human globulin reagent for 30 minutes. Without centrifuging, examine each suspension for agglutination under a microscope.

Pyrogens or Bacterial endotoxins Complies with the “Pyrogen Test” (Appendix 8.2) or, preferably and where justified and authorized, with a validated in vitro test such as the “Test for Bacterial Endotoxins” (Appendix 8.5).

          For the pyrogen test, use a volume of the solution containing not less than 50 IU of factor VIII:C per kg of the rabbit’s weight.

          Where the bacterial endotoxin test is used, it contains less than 0.035 Endotoxin Unit per IU of factor VIII:C.

Sterility Complies with the “Sterility Test” (Appendix 10.1).

Assay

          FACTOR VIII Carry out the “Biological Assay of Human Coagulation Factor VIII” (Appendix 15.1.3). The estimated potency is not less than 80 per cent and not more than 120 per cent of the stated potency. The confidence limits (P = 0.95) are not less than 80 per cent and not more than 120 per cent of the estimated potency.

          VON WILLEBRAND FACTOR For preparation intended for the treatment of von Willebrand’s disease, carry out the “Biological Assay of Human von Willebrand Factor” (Appendix 15.1.9). The estimated potency is not less than 60 per cent and not more than 140 per cent of the stated potency.

(Note Pending the availability of an International Standard for von Willebrand factor concentrate calibrated for use in the collagen-binding assay, only the ristocetin cofactor assay may be used.)