Porcine factor VIII (Hyate: C®): in vitro stability, microbiological safety and effect of heparin[Note 1. This material was presented in part as a poster ...]

The in vitro stability of porcine factor VIII (PF VIII) was evaluated when it was reconstituted with sterile water (PF VIII SW ) to ≈ 30 U PFVIII mL −1 , as per the manufacturer’s recommendations, and stored in plastic syringes at room temperature, with and without heparin and at four different dilutions. PF VIII was prepared antiseptically without laminar airflow and remained sterile at room temperature for 1 week. PF VIII SW retained at least 88% of baseline activity for 48 h and 74–86% for 72 h. Addition of heparin 1 unit mL −1 solution resulted in a decrease in the stability of PF VIII SW to 72–74 % of baseline values by 24 h. Reconstituted PF VIII SW , further diluted with normal saline to 10–24 U PF VIII mL −1 , retained 98% of baseline activity for 48 h and 84% of baseline for 72 h. PF VIII diluted to 6 U mL −1 , however, retained 100% baseline activity for only 24 h, and declined to 71% and 64 % of baseline by 48 and 72 h, respectively. PF VIII reconstituted with normal saline, instead of sterile water, retained 90% or more of baseline activity for a minimum of 4 days. Once reconstituted, PF VIII appeared to be more stable at room temperature than when stored in the refrigerator. These in vitro stability studies confirm that PF VIII (30 U mL −1 ) can be given effectively by prolonged continuous infusion, since it retains 88% baseline activity at room temperature in a plastic syringe for a minimum of 48 h, remains sterile and will maintain baseline PF VIII levels when further diluted with saline.