# Pharmacokinetics of Marine-Derived Drugs
## 3 Pharmacokinetics Studies in Animals
### Absorption
#### 3.1.1 Algal-Derived Compounds
\begin{table}
\begin{tabular}{c c c c c c c c} \hline \hline
**Compounds** & \begin{tabular}{c} **Animals/Dose** \\ **(mg/kg/vehicle)** \\ \end{tabular} & **Administration** & **T\({}_{\rm max}\) (h)** & **T\({}_{\rm 1/2}\) (h)** & \begin{tabular}{c} **C\({}_{\rm max}\)** \\ **(ug/mL)** \\ \end{tabular} & **AUC\({}_{\rm 0+1}\)** & **Reference** \\ \hline Lipid extract of gonads & Rabbits/15/starch & & & & & & \\  & slime & & & & & \\  & \multirow{2}{*}{\begin{tabular}{} \end{tabular} } & \multirow{2}{*}{peroral} & \multirow{2}{*}{3.0} & \multirow{2}{*}{8.8} & 107 & 313 & [29] \\  & & Rats(0.7/EOH, & & & & & \\  & cremophor EL 10\% & & & & & & \\  & in saline & & & & & & \\  & Mice/0.278/ & & & & & & \\  & dimethylformamide/ & & & & & & \\  & sterile saline 10:90 & & & & & & \\  & \multirow{2}{*}{\begin{tabular}{} \end{tabular} } & \multirow{2}{*}{i/v} & \multirow{2}{*}{N.d.} & 0.26 & \multirow{2}{*}{0.001} & \multirow{2}{*}{N.d.} & [57] \\  & & & & & & & \\  & \multirow{2}{*}{\begin{tabular}{} \end{tabular} } & \multirow{2}{*}{i/v} & \multirow{2}{*}{N.d.} & 5.6 & 0.28 & 0.067 & \multirow{2}{*}{[58]} \\  & Mice/0.24/water & & & & & N.d. & N.d. & 0.011 & \\  & Mice/0.32/water & & & & & & 3.7 & 0.011 & 0.058 \\  & & & & & & & \\  & \multirow{2}{*}{\begin{tabular}{} \end{tabular} } & \multirow{2}{*}{i/v} & \multirow{2}{*}{N.d.} & 0.04 & \multirow{2}{*}{N.d.} & 0.33 & \multirow{2}{*}{[59]} \\  & & & & & & & \\  & & & & & & & \\  & \multirow{2}{*}{\
\begin{tabular}{} \end{tabular} } & \multirow{2}{*}{i/v} & \multirow{2}{*}{N.d.} & 0.09 & \multirow{2}{*}{N.d.} & 0.21 & \multirow{2}{*}{[60]} \\  & Mice/0.04/phosphate & & & & & & & \\  & buffer containing & & & & & & \\  & 30\% DMSO & \(\upmu\)g & & & & & & \\  & \multirow{2}{*}{
\begin{tabular}{} \end{tabular} } & \multirow{2}{*}{N.d.} & 28.76 & \multirow{2}{*}{0.013} & \multirow{2}{*}{0.62} & \multirow{2}{*}{[59]} \\ \hline \hline \end{tabular} Note: i/v, intravenous; i/p, intraperitoneal; s/c, subcutaneous; i/n, intranasal; T\({}_{1/2}\), apparent half-life of elimination; AUC\({}_{0+1}\), the area under the curve; C\({}_{\rm max}\), maximum concentration (\(\upmu\)g/mL) for plasma; T\({}_{\rm max}\), time at which C\({}_{\rm max}\) is observed. MRT, mean residence time; the results are expressed as the mean \(\pm\) SD; \(t_{1/2~{}\alpha}\), distribution half-life; \(t_{1/2~{}\beta}\), elimination half-life. * mean values (\(n\) = 5); **\(\frac{t_{1/2~{}\alpha}}{t_{1/2~{}\beta}}\)** (for two-compartment model); N.d., no data; MW, molecular weight.  
\end{table} 
Table 2: _Cont._(MW = 56 kDa) penetrates across the Caco-2 cell monolayer by active transport with maximal activity at one hour, followed by a rapid decrease. Later, the clathrin endocytic pathway was established to be involved in the absorption and transport of fucoidan [32]. All these results proved that fucoidan rapidly absorbs after different routes of administration. Figure 1: _Cont._  
Griffithsin (GRFT) is a homodimeric lectin containing 121 amino acids, with a total of six oligosaccharidesoharding binding sites, and with terminal oligomanose residues on asparagine (N)-linked Man5-9-GlcNAc2 structures. It has been isolated from the red algae _Griffithsia_ spp. [67]. GRFT shows promising anti-viral activity [67; 68; 69]. GRFT was administered to rats i/v (10-20 mg/kg), perorally (10 mg/mL), and subcutaneously (s/c; 10 or 20 mg/kg). Additionally, the pharmacokinetics of GRDT was studied after 10 days peroral administration at the dose of 20 or 40 mg/kg. The concentration of GRFT in serum after i/v injection was dose dependent, with mean concentrations of 74 and 141 ug/mL at 10 and 20 mg/kg, respectively, and then rapidly decreased. The plasma concentration-time function was two-exponential with mean t\({}_{1/2\alpha}\) of 0.5 h and t\({}_{1/2\beta}\) of 1.9 h, without statistically significant dose dependence. After s/c injection, GRFT appeared in serum at 15 min and gradually increased up to T\({}_{\text{max}}\) of 4 h, which suggests its slow absorption.