1) To simulated a one compartment pharmacokinetic model with first-order elimination and multiple IV. bolus dosing.
BACKGROUND:
By an arrangement of beakers and a constant head water reservoir, it is possible to simulate a one compartment pharmacokinetic model. The constant-head water reservoir produces a constant clearance of drug from the plasma beaker and a single elimination pathway is represented by a single siphon from the plasma beaker.
The constant flow of water through the system, causes a first order dilution of the marker, potassium permanganate. You will sample the marker concentrations periodically and analyze the data using the pharmacokinetic methods appropriate to measure the parameters of the system.
METHOD:
Identify the plasma component to the set-up. Make sure that the water reservoir is full. Turn on the stirrer in the plasma beaker and adjust for gentle mixing. Establish an elimination flow rate of 25 ml/min.
You will be collecting plasma samples at every five minutes for 80
minutes with a bolus doses of 10 drops 'injected' at 0, 15, 30, 45, and 60 minutes. Arrange and label test-tubes to accommodate the samples.
Plasma samples. Collect the 5 ml sample at the times designated, quickly by pipette. Don't rinse the pipette between samples.
Each sample will be analyzed spectrophotometrically at 540 nm.
A standard curve will be provided. Some of the later samples may need to be diluted to give absorbance readings below 1. Remember to apply this dilution factor in your analysis of the results.
Calibration of the Turner 330 model spectrophotometer
WRITE-UP:
Describe the apparatus, the working differential, and working integrated equation. Plot Cp versus time on semi-log graph paper. Calculate kel from the slope after the first and last dose, calculate t1/2.
Time (min) | Dilution Factor | Absorbance | Concentration (from Standard Curve) |
0 | |||
5 | |||
10 | |||
15 | |||
20 | |||
25 | |||
30 | |||
35 | |||
40 | |||
45 | |||
50 | |||
55 | |||
60 | |||
65 | |||
70 | |||
75 | |||
80 |
Copyright 2001 David W.A. Bourne