The Concentration Of Gentamicin Discussion Paper

To calculate the amount of gentamicin used, we need to know the volume of the solution in each drop. Typically, one drop of ophthalmic solution is around 0.05 mL.

Explanation-

The concentration of gentamicin is 0.3% w/v, which means that there are 0.3 grams of gentamicin in 100 mL of solution.

So here we have to convert this to milligrams in 0.05 mL (one drop) of solution:

0.3% w/v = 0.3 g/100 mL 1% w/v = 1 g/100 mL 0.05% w/v = 0.05 g/1000 mL (multiply both numerator and denominator by 0.5) 0.05% w/v = 0.00005 g/mL

Therefore, there are 0.00005 g of gentamicin in each 0.05 mL drop of solution.

Step 1)

Now we can calculate the total amount of gentamicin used over the course of the treatment: The Concentration Of Gentamicin Discussion Paper

For the first 5 days: 12 drops per day (one drop every 2 hours) x 5 days = 60 drops per eye.

Step 2)

For the next 2 days: 4 drops per day x 2 days = 8 drops per eye.

Total drops per eye: 60 + 8 = 68 drops.

Total amount of gentamicin per drop: 0.00005 g

Total amount of gentamicin used per eye: 68 drops x 0.00005 g/drop = 0.0034 g.

Step 3)

Since we are treating both eyes, the total amount of gentamicin used is:

0.0034 g/eye x 2 eyes = 0.0068 g

Final answer-

The total amount of gentamicin used in the prescribed course of treatment of 0.3% w/v gentamicin drops, one drop every 2 hours for 5 days, then one drop four times daily for 48 hours in both eyes, is 6.8 milligrams The Concentration Of Gentamicin Discussion Paper