Question

6. An HPLC method was developed for the separation and determination of ibuprofen in rat sampice as part of a study of thetime course of the drug in laboratory animals. Several standards were measured and produced the following data: ouproten concentration (ugmL) 0.5 1.0 2.0 3.0 6.0 8.0 10.0 15.0 Peak area 5.0 10.1 17.2 19.8 39.7 57.3 66.9 Next a 15 ugiml sample of ibuprofen was administered orally to a laboratory rat. Blood samples were drawn HPLC. The following results were obtained. 95.3 at various times after administration of the drug an analyzed with Time (hours) Peak area 0.5 1.0 2.0 3.0 4.0 6.0 8.0 91.3 80.2 52.1 38.5 24.2 21.2 18.5 15.2 Find the concentration of ibuprofen in the blood for each of the above times using the calibration data. On a percentage basis (you need to show these calculations), what half hour period (It 2nd, 3rd, etc.) is most of the ibuprofen lost? You need to turn in your spreadsheet and all calculations for this problem. (20 pts)

Answer 1

Given standard i burprofen values are

Std (ug/ml) STD peak area

0.5 . 5

1. 10.1

2 17.2

3 . 19.8

6. 39.7

8 . 57.3

10 66.9

15 95.3

Step 1 calculate slope

As slope = y2- y1 / x2-x1

We get slope m = 6.23

Step 2 calculate intercept

From above values

We get Intercept = 3.27

So equation is

Y = 6.23 X + 3.27

Sample of I burprofen 15ug/ml injected to rat and concentration after duration wise is as follows

Time (hrs) . area Concentration

0. 0 0

0.5. 91.3 13.97

1.0. 80.2 12.21

1.5 52.1 7.75

2 38.5 5.59

3. 24.2 . 3.32

4 21.2 2.85

6 18.5 2.42

8 . 15.2 1.89