Ask the Expert: [an odd but very interesting PK problem]

here is a set of data describing the conc and the dose per iv repetitive injection of an endogenous substance. Can anything be said about the relative injected dose versus the endogenous release? can any of the data be used to determine the rate of metabolism or excretion?

I have looked at the rate of change of the concentration versus the injected dose and found a kendalls / spearman correlation of about zero ( p value .o2), suggesting that the dosing has no relation to the concentration

I couldnt figure out how to post columns, so I did each separately

time conc
baseline 38.67
1 39.84
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
concentration
38.67 this corresponds to baseline
39.84
40.56
42.21
43.81
45.3
46.72
48.44
50.96
52.59
53.83
55.18
55.88
56.6
58.03
59.85
61.62
62.76
65.48
67.56
68.77
70.35
72.39
74.94
76.76
78.78

amt injected

2.461 at time 1
2.441
2.433
2.519
2.592
2.671
2.740
2.840
2.900
2.935
2.977
2.927
2.931
2.987
3.048
3.107
3.159
3.139
3.130
3.212
3.297
3.320
3.479
3.663
3.802