Question

1. A new medication for treatment of ear infections is currently going through clinical trials. A placebo counterpart is needed. To make a visually similar placebo, you will combine a dye of the same color and dilute it with a suitable solvent. For the placebo, you need to have 0.6 mL of dye solution in 10 mL of compounded product. You only have a 10 mL graduated cylinder and glass vials available. Complete the sections below to describe how you would make a liquid aliquot to prepare the placebo.

Hint (helpful) proportion:

1. How many mL of dye soln are needed to form the stock solution?

(Hint:  You will use a 10-mL graduated cylinder that is calibrated 1mL increments.  It will be easiest to use a whole number that is easily divisible by 0.6 mL)

2. What size aliquot of the stock (mL of stock) would you use if you were minimizing waste?  

3. How many mL of diluent are needed for the stock solution?

(Hint: you will first need to solve for  and then solve for .)

4. How many mL of diluent are needed to form the final 10-mL placebo solution?

5. Suppose the dye soln was dye in alcohol, and you used an alcohol to prepare the aliquot. Explain how you would combine the aliquot and water, if the goal was to prepare athe placebo as a hydroalcoholic solution.

Please answer 4 and 5 in detail

Answer 1

a ) 0.6 mL dye solution needed to form the stock solution. A stock solution is a concentrated solution that will be diluted to some lower concentration for actual cost.Here, 0.6 mL of dye solution in 9.4 mL compound product is used for the preparation of placebo.

Total volume solution = 9.4 + 0.6 = 10 mL

b ) To make a dilution , add a small quantity of a concentrated stock solution to an amount of pure solvent.

Mix 1 mL of the stock solution with 9 mL of water or other diluent.(1:10) dilution is used to prepare 10 mL of diluted solution from stock solution.

C ) Here , 0.6mL of dye solution with 9.4 mL diluent are needed for the preparation of stock solution.

d ) 1 ml of stock solution is diluted with 9 ml of diluent to form final 10 mL placebo solution.