Exposure assessment of epidermal growth factor to various tissues in mice after intravenous and subcutaneous administration

Objectives This study was conducted to examine the tissue distribution of human recombinant epidermal growth factor (EGF) after multiple intravenous and subcutaneous injections in mice. Methods Male BALB/c mice were divided into (1) EGF 1 mg/kg intravenous dose, (2) EGF 5 mg/kg intravenous dose, (3) drug-free intravenous control, (4) EGF 1 mg/kg subcutaneous dose, (5) EGF 5 mg/kg subcutaneous dose and (6) drug-free subcutaneous control groups. EGF and drug-free dosing solutions were injected by intravenous and subcutaneous injections once a day for 3 days. EGF concentrations in serum and tissues of kidney, liver, lung, small intestine and tongue were determined by ELISA. Key findings As the intravenous and subcutaneous doses were increased from 1 to 5 mg/kg, serum C_max and area under the concentration-time curve (AUC) values were increased dose-proportionally. In lung, tongue and small intestine, increases in AUC were dose-proportional after intravenous injections, but greater than dose-proportional after subcutaneous injections. The fold-increases in C_max and AUC values were lowest in liver and highest in kidney. Conclusion Based on C_max and AUC data, the systemic exposure achieved by subcutaneous injections was comparable with that achieved by intravenous injections.