Stability and sterility of a recombinant factor VIII concentrate prepared for continuous infusion administration.
Minipumps may facilitate cost-effective and convenient continuous infusion (CI) therapy for severe hemophilia A. This study evaluated the in vitro sterility, ability to support bacterial growth, and specific activity stability of a recombinant factor VIII (FVIII; Bioclate, Centeon) delivered by simulated CI at a variety of temperatures and after the addition of heparin or antibiotic. Closed system CIs of Bioclate (89.5 IU/ml) with and without heparin were sampled and cultured over a 6 day period. Bioclate (53.7 IU/ml) with and without heparin or vancomycin was inoculated with 102-105 CFU/ml of S. aureus, S. epidermidis, Escherichia coli, E. cloacae, or Y. enterocolitica and assessed by quantitative culture after 1 and 3 days. The stability of Bioclate (50, 100, and 250 IU/ml) at three temperatures (21 degrees C, 37 degrees C, and 39 degrees C) with and without heparin or vancomycin was tested over a period of 28 days. FVIII activity was measured in triplicate by a chromogenic assay (Coamatic Factor VIII, Chromogenix) and purity evaluated by Western blot. No bacterial growth was detected during CI of FVIII for up to 6 days. Following bacterial inoculation, there was rapid growth (>3 log increase) of all tested bacterial species except S. aureus which only displayed a 1 log expansion at 3 days. The addition of heparin containing 9.45 microg/U benzyl alcohol had no effect on bacterial growth. The addition of vancomycin caused a modest suppression of S. aureus growth but not of E. coli. Diluent alone did not support bacterial growth. Neither concentration, increased temperature, nor the addition of heparin or vancomycin had a significant effect on FVIII activity stability. Samples retained >75% baseline activity for between 3 and 7 days, except the infusion of Bioclate 50 IU/ml plus heparin maintained at 21 degrees C which remained stable for 28 days. Western blot analysis supported the activity assay findings. Standard and concentrated preparations of Bioclate are suitable for CI when delivered by the MiniMed 404-SP minipump. Because of the observed nutritive capability of this FVIII concentrate for sustaining bacterial growth, any contamination could result in systemic infection.
Belgaumi
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AF
Department of Hematology/Oncology, St. Jude Children's Research Hospital, Memphis, Tennessee, USA.
Patrick
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CC
Deitcher
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SR
D001419:Bacteria / Q000254:growth & development; D004340:Drug Contamination; D004355:Drug Stability; D004356:Drug Storage; D005169:Factor VIII / Q000008:administration & dosage / Q000737:chemistry* / Q000494:pharmacology / Q000592:standards; D006493:Heparin / Q000494:pharmacology; D006801:Humans; D007262:Infusions, Intravenous / Q000295:instrumentation; D011994:Recombinant Proteins / Q000008:administration & dosage / Q000737:chemistry / Q000494:pharmacology / Q000592:standards; D012449:Safety; D013045:Species Specificity; D013696:Temperature; D014640:Vancomycin / Q000494:pharmacology
D011994:Recombinant Proteins; D014640:Vancomycin; C078147:F8 protein, human; D005169:Factor VIII; D006493:Heparin