Determination of VIT 45 (IND#63,243 - American Regent) Removal by Closed Loop in Vitro Hemodialysis System

Abstract

Background

Intravenous iron is typically administered during the hemodialysis (HD) procedure. The extent of VIT 45, a novel intravenous iron formulation, removal by high-flux (HF) or high-efficiency (HE) dialysis membranes at various ultrafiltration rates (UFR) is unknown.

Methods

An in vitro HD system was constructed to determine the dialyzabiltiy of iron from a normal saline compartment (NSC) containing 1000 mg iron of VIT 45. The in vitro system utilized a 6-L closed-loop SBS system that was subject to 4 different HD conditions conducted over 4 hours: HE membrane + 0 ml/h UFR; HE membrane + 500 ml/h UFR; HF membrane + 0 ml/h UFR; HF membrane + 500 ml/h UFR. Blood flow and dialysate flow rates were 500 ml/min and 800 ml/min, respectively. The dialysate compartment was a 6-L closed-loop system. A volumetric HD machine controlled all blood, dialysate, and ultrafiltration rates. NSC and dialysate compartment samples were taken at various time points and iron elimination rate (k_hd) and HD clearance (Cl_hd) was determined. Iron removal from the NSC > 15% was considered clinically significant.

Results

The percent removal of iron from the NSC was < 0.5% at all time points in the study. Dialysate recovery of iron was negligible: 1.7–5.1 mg. VIT 45 removal elimination rates from NSC were less than -0.001 h ⁻¹ (range -0.0002 ± 0.0001 to -0.0001 ± 0.0002 h ⁻¹) for all study conditions.

Dialyzer type or UFR did not effect iron removal.

Conclusion

HF or HE dialysis membranes do not remove clinically significant amounts of VIT 45 over a 4-hour in vitro HD session. This effect remained constant even controlling for UFR up to 500 ml/hour. VIT 45 is not dialyzed by HE or HF dialysis membranes irrespective of UFR. (Int J Artif Organs 2006; 29: 1062–6)