**Practical problem 2**

**iv.** Maintenance interval = maintenance dose/ rate of elimination

and the maintenance dose reduced proportionately: = 546 x 8/9.75 ~ 437 mg.

For a practical loading schedule, the maintenance interval should be lowered to say 8.0 hrs

The analytical method of assaying paracetamol relies on the introduction of a nitro group into the molecule after the removal of plasma proteins through precipitation. The resultant nitrophenol compound which is formed has a deep yellow colour in an alkaline medium and

CH3 C NH

NO2

O O

OH

**i.** Describe how you would construct the standard curve for determination of parace‐

**2.** Design an experiment that would enable you to determine the t1/2 of paracetamol

OH-

CH3 C NH

O-

NO2

= 546/56

496 Drug Discovery

= 9.75 hrs

= Ctox.V

= 36.4 x 20

= 728 mg

= Css x V

= 36.4 x 10 = 364 mg

**Practical problem 1**

absorbs at 430nm Figure 12.

O

NH

OH

tamol concentration.

HNO2

**Figure 12.** Formation of a chromogenic nitro compound from an analgesic Acetaminophen

CH3 C

K=ln X1 X t1-t2

**v.** The initial loading dose

**vi.** The loading dose at steady state

Liver damage can be induced by 20% w/v carbon tetrachloride. Given 10mg/ml pentobarbitone and 10mg/ml Phenolbarbitone, design an experiment that demonstrates that the duration of action of short acting barbiturates are dependent on the integrity of the liver.
