Enhanced oral bioavailability and tissue distribution of ferric citrate through liposomal encapsulation

Our previous study found that ferric citrate-loaded liposome (FAC-LIP) exhibited stable physical characteristics and have better efficacy to treat anemia of inflammation (AI) than free ferric citrate (FAC). This study was aimed at oral pharmacokinetics of both FAC-LIP and FAC in Sprague Dawley (SD) rats. Results showed that the main pharmacokinetic parameters of FAC-LIP in vivo were as follows: Cmax of 445.89 ± 23.56 μg/mL, Tmax of 4 h, t1/2 of 13.01 ± 2.04 h, MRT of 20.54 ± 2.06 h and AUC0-24 h of 6446.1 ± 516.58 hμg/mL. The relative bioavailability of FAC-LIP formulation was 215.7%, nearly 2-fold in comparison with free FAC formulation. FAC-LIP showed a sustained-release effect, a wide absorption and a complete elimination. These results support the fact that FAC-LIP has the potential of improving oral bioavailability and reducing iron accumulation in liver, which could influence the available iron level in the blood system. FAC-LIP could be used as an effective iron supplement.