Lymphatic transport of puerarin occurs after oral administration of different lipid-based formulations to unconscious lymph duct-cannulated rats

This study investigated the potential of targeted intestinal lymphatic transport of puerarin via a lipid formulation approach. Three formulations of PEG nanoemulsion, nanosuspension and an oil suspension containing puerarin were examined with the lymph-cannulated anaesthetized rat model. Plasma and lymph samples were analyzed by HPLC. Lymph triglyceride was measured using an enzymatic colorimetric technique. After 8 h, the total administered dose accumulated in the thoracic lymph duct was analyze. Nanoemulsion, nanosuspension and oil suspension was 0.065 ± 0.006%, 0.137 ± 0.018%, 0.021 ± 0.002% of the administered dose, respectively. In nanoemulsion, nanosuspension and oil suspension group, the systemic bioavailability of oral puerarin was 11%, 16% and 11% for lymph-cannulated rats, 41%, 67% and 18% for control rats. Absorption into the intestinal lymph should thus contribute to ∼30%, 51% and 7% of the systemic bioavailable puerarin. This data indicated that lipid-based nano drug formulation produced higher lymph concentrations of puerarin than oil suspension. The nanosuspension formulation may be considerable in terms of increased local concentrations in lymphoid tissue.