# Pharmacokinetics of Marine-Derived Drugs
## 2 Analytical Methods Used in Pharmacokine Studies  
Different analytical methods are implemented for the evaluation of pharmacokinetic parameters. The methods most commonly used for the analysis of marine-derived compounds in biomaterials are presented in the Table 1. For the direct analysis of active molecules, these methods include fluorescein labeling, radioactive labeling (total radioactivity analysis (TRA) and radioimmunoassay (RIA)), matrix-assisted laser desorption/ionization (MALDI), MALDI imaging mass spectrometry (IMS), high- performance liquid chromatography (HPLC) or liquid chromatography (LC) with evaporative light- scattering detection (ELSD), fluorescent detection, different mass spectrometry (MS), electrospray ionization (ESI), or UV detection. The other group of methods is based on the enzyme-linked immunosorbent assay (ELISA) and the biomarker approach. The analysis of active compounds in biomaterials requires high sensitivity. The sensitivity depends on the nature of the active compound and the biomaterial. The pharmacokinetics of some compounds, such as fucoidan or aplidine, has been studied using different methods, showing that biomarker-based assays provide high sensitivity and broad linearity (Table 1).  
\begin{table}
\begin{tabular}{c c c c c c c} \hline \hline \multirow{2}{*}{**Method**} & **Recovery** & **Linearity** & \multirow{2}{*}{**Compound**} & \multirow{2}{*}{**Source**} & \multirow{2}{*}{**Biomaterial**} & \multirow{2}{*}{**Reference**} \\  & **(\%)** & **Range (\(\mu\)g/mL)** & & & & \\ \hline Biomarker assay & & & & & & \\ Anti-Xa activity & - & 0.027–0.217 & \multirow{2}{*}{Fucoidan} & Brown algae _Fucus_ & Plasma, & \\ Biomarker assay & & & & & & \\ Anti-Xa activity & - & 0.014–1.13 * & \multirow{2}{*}{Fucoidan} & Brown algae _Fucus_ & & \\ Biomarker assay & & & & & & \\ Dypeptidyltypetidase & - & 1.9–710 & \multirow{2}{*}{Lipid extract of gonads} & \multirow{2}{*}{_Strongylocentrotus_ & Plasma & [29] \\ IV inhibition & & & & & _dreuchiensis_ & \\ Biomarker assay & & & & & & \\ Lactate & - & 0.01–7.05 & \multirow{2}{*}{Glycopeptide} & Sea urchins & \multirow{2}{*}{Plasma} & \multirow{2}{*}{[30]} \\ dehydrogenase & & & & & & \\ activity & & & & & & \\ Competitive ELISA & - & 0.078–80 & \multirow{2}{*}{Fucoidan} & Brown algae _Fucus_ & & \\ Fluorescent labeling & - & - & \multirow{2}{*}{Fucoidan} & Brown algae _Fucus_ & Plasma & [31] \\  & & & & & _vesticolosus_ & \\ Gas chromatography & 82–87 & 0.3–10 & \multirow{2}{*}{Halomon} & Brown algae _Fucus_ & Plasma & \\ HPLC with & & & & & _vesticolosus_ & \\ derivatization & 96.6–106.4 & 0–80 *** & \multirow{2}{*}{Fucoidan} & \multirow{2}{*}{_Laminaria japonica_} & Plasma & [34] \\ HPLC with & & & & & & \\ fluorescence & 93.3–96.5 & 0.5–100 & \multirow{2}{*}{Fucoidan} & Laminaria & \multirow{2}{*}{Plasma} & \multirow{2}{*}{[35]} \\ detection & & & & & & \\ HPLC with & & & & & & \\ postcolumn & 95.5–99.2 & 0.5–150 & \multirow{2}{*}{Fucoidan} & Laminaria & \multirow{2}{*}{Serum} & \multirow{2}{*}{[36]} \\ fluorescence derivatization & & & & & & \\ HPLC with UV & & & & & \\ detection & 86.2–100.1 & 0.5–500 & \multirow{2}{*}{Dindolionnepyrane (2,5-BHPA)} & Marine fungi & \multirow{2}{*}{Plasma} & \multirow{2}{*}{[37]} \\  & & & (2,5-BHPA) & & & \\ \hline \hline \end{tabular}
\end{table}
Table 1: Analytical methods used for the analysis of marine-derived compounds in biomaterials.