Medilol

Question No: 1:

Aphrodisia is a new drug when tested in human. It was given orally 250 mg and I/V dose of 50mg sample of blood were collected at various time intervals after administration plasma function were arranged for active analysed for active ingredient.

Find:

• MEC of Aphrodisia is 2.3 microgram per millilitre
• What is onset time?
• What is Tmax?
• What is duration of action of drug?
• What is Cmax?
• Assume that the drug is 100 percent systematically available?
• What is AUC of absorption?
• Calculate absolute bioavailability of drug?

Principle:

Plasma drug concentration profile

• Administration of drug
• Blood sampling
• Plasma extraction
• Analysis
• Dose response curve
• Graph between time and plasma concentration

Theory:

• MEC is the minimum effective concentration: It is the minimum amount of drug that shows the therapeutic effect.
• Duration of action: It is the time of which the drug concentration remains above the MEC.
• Therapeutic window: The drug concentration range between MEC is the therapeutic window.
• Tmax is the maximum time at which max plasma drug concentration is derived

Tmax: Ka. FD/Vd(Ka-K)

• Cmax: It is max plasma by concentration achieved at Tmax.
• Area under curve: It is the plasma drug concentration.

AUC = ½(t2-t1)(C2-C1)+ ½ (t3-t2)(C2)---------+ ½  (tn-tn-1)(Cn-Cn-1)

• Bioavailability:

It is the rate and extent of active drug that reaches to the systemic circulation.

F= AUC_test/AUC_ref into 100

F= {AUC_test into Dose/AUC_ref into dose} into 100

Procedure:

• Graph of plasma drug concentration versus time was plotted both oral and Intravenous route administration.
• The required parameters were determined from the graph.
• The AUC was also calculated from graph by trapezoidal method.
• Bioavailability was calculated.