I want to generate R code for a two-compartment pharmacokinetic model with dose intravenous administration. The two compartment model defines the differential equations governing the behavior of the two-compartment system. This system consists of a central compartment (Cc) and a peripheral compartment (Cp). 
The rate of change of concentration in the central compartment (dCc) is calculated as the sum of three terms:
-	The first term represents the linear elimination of the drug from the central compartment, where the rate of linear elimination proportional to the concentration in the central compartment (Cc), and Cl is the clearance, the amount of plasma cleared of drug per unit time.
-	The second term describes the flow between the central and peripheral compartments, where represents the flow from Cc to Cp, and Q is the flow between compartments. In this second term, we only take into account here Cc, Cp and Vc and not Vp. 
-	The third term models the non-linear elimination of the drug from the central compartment, following Michaelis-Menten kinetics, where represents the rate of non-linear elimination, with Vmax being the maximum elimination rate and Km the Michaelis-Menten constant. 
The rate of change of concentration in the peripheral compartment (dCp) is calculated as the flow from the central compartment to the peripheral compartment minus the flow from the peripheral compartment to the central compartment. This is expressed as, where Q is the flow between compartments and Vp is the volume of the peripheral compartment. Vc is not used in this differential equation. The first differential equation include Vc and not Vp, but second differential equation include Vp and not Vc.
These differential equations describe how the drug concentrations in the central and peripheral compartments change over time, considering both linear and non-linear drug elimination, as well as the flow between compartments.
Then:
-	Parameter definition
o	Volume of the central compartment (liters) = 48.58  
o	Volume of the peripheral compartment (liters) = 33.47  
o	Clearance (ml/day) = 7.05   
o	Maximum elimination rate (ug/day) = 0
o	Michaelis-Menten constant (ug/ml) = 5
o	Flow between compartments (ml/day) = 49.04
o	Dose (ug) = 10000
o	Initial concentration in the central compartment (ug/ml) = dose / Vc  
o	Initial concentration in the peripheral compartment (ug/ml) = 0

-	Function defining the differential equations of the model with library(deSolve). Differential equations should be defined with a more explicit approach.
- Integration time from 0 to 35.
- Initial conditions:  Initial concentration in the central compartment and Initial concentration in the peripheral compartment.
- Solving the differential equations with ode().
- Extracting results
- Plotting concentrations for central and peripheral compartments in the same plot with a legend size of 1. Legend position on the upper-right of the graph.

