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Cryoprecipitated Antihemophilic Factor

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

          Cryoprecipitated Factor VIII is a sterile, frozen concentrate of human antihemophilic factor1 prepared from the factor VIII-rich cryoprotein fraction of human plasma obtained from suitable whole blood donors from a single unit of plasma derived from whole blood or by plasmapheresis, collected and processed in a closed system. It contains no antimicrobial preservative.

          It meets the requirements of the test for potency by comparison with the Standard Antihemophilic Factor (Factor VIII) or with a working reference that has been calibrated with it, in having an average potency of not less than 70 IU per container, made at intervals of not more than 1 month during the dating period.

Description Yellowish frozen solid. On thawing becomes a very viscous, yellow, gummy liquid.

Strength available Not less than 70 IU of factor VIII and not less than 140 mg of fibrinogen per unit.

Dose Intravenous infusion after diluted with sterile saline solution, as prescribed by the physician.

Expiration date When stored under the prescribed condition, the expiration date is not later than 1 year from the date of collection of source materials.

Packaging and storage Cryoprecipitated Factor VIII shall be kept in tightly closed containers at a temperature of –18º or below.

Labelling Complies with the “General Information for Biological Products”, p. 177. In addition the label on the container states (1) the identification number of the donor from whom the source material was obtained; (2) a warning not to use if there is evidence of breakage or thawing; (3) instructions to thaw it before use to a temperature between 20º and 37º, and use as soon as possible; (4) that it is to be used within 4 hours after the container is entered; (5) that it is for intravenous administration; (6) that a filter is to be used in the administration equipment.

Fibrinogen Not less than 140 mg per container. Dilute 1 ml of the solution to 10 ml with saline TS. To a volume of the dilution containing 15 mg of fibrinogen add sufficient thrombin to coagulate the protein and allow to stand for 2 hours. Collect the clot, wash with saline TS and carry out the determination as described in the “Determination of Nitrogen” (Method II, Appendix 6.7).

Assay Compare the potency of cryoprecipitated factor VIII with that of an appropriate plasma or intermediatepurity standard, by measuring its ability to correct the prolonged activated partial thromboplastin time of hemophilia A plasma or by another suitable method.

¹ When cryoprecipitated factor VIII is produced from fresh-frozen plasma (frozen within 8 hours of donation), the yield should be more than 400 IU per litre of starting plasma. The average yield of factor VIII as freeze-dried cryoprecipitate is then at least 300 IU per litre of starting plasma. The acceptable yield shall be controlled by the Ministry of Public Health or by the National Blood Centre, Thai Red Cross Society.