Pharmacokinetic Study of Bioactive Glycopeptide from Strongylocentrotus droebachiensis After Intranasal Administration to Rats Using Biomarker Approach

A glycopeptide fraction (GPF) from internal organs of green sea urchins (Strongylocentrotus droebachiensis Müller, Strongylocentrotidae) has been reported to be an effective bronchitis treatment. In this study, we evaluated the pharmacokinetic and tissue distribution of GPF, following single and repeated intranasal (i/n) administration over the course of seven days in rats. The method measuring lactate dehydrogenase as biomarker was used to analyse the plasma and tissue concentrations of GPF. GPF appears in the plasma 15 min after single i/n administration (100 µg/kg) and reaches its maximum at 45 min. The area under the curve (AUC)(0–24) and C(max) were similar using both i/n and intravenous administration, while mean residence time (MRT) and T(1/2) after i/n administration were significantly higher compared with intravenous (i/v) administration. The absolute bioavailability of GPF after i/n administration was 89%. The values of tissue availability (f(t)) provided evidence about the highest concentration of GPF in the nose mucosa (ft = 34.9), followed by spleen (ft = 4.1), adrenal glands (ft = 3.8), striated muscle (ft = 1.8), kidneys (ft = 0.5), and liver (ft = 0.3). After repeated dose administration, GPF exhibited significantly higher AUC(0–24) and MRT, indicating its accumulation in the plasma.