Rx351 Lab – Module 4 Assignment (40pts)
Name __________________________________________________________________
Complete and submit on Canvas. You must show all work to receive full credit. Do not leave off units and make sure to use leading zeros. Dropping units in your answer or failure to use a leading zero in an answer will result in no credit for that answer, even if the number itself is co
ect.
1. (6pts) It is not uncommon for an ingredient used in non-sterile compounding to have the concentration of its solute (API or chemical being dissolved) expressed as a w/w% (instead of a w/v%). If that is the case, you will typically need to use the density or specific gravity (SG) of the solution to convert between grams of solution and milliliters of solution.
Pay close attention to whether you are provided the density/SG of the solution or the density of the solute (what is being dissolved in the solution).
a. The density of so
itol 70% w/w solution is 1.285g/ml. What is the concentration of so
itol in the solution, expressed as a w/v% concentration?
. Try the same calculation, but instead of using the SG of the so
itol solution, use the density of so
itol powder (1.49g/ml) to convert so
itol 70% w/w to a w/v% concentration. Do the calculation without using the density of the solution given to you in Question 1. (You should get pretty close to the same answer as in part a!)
2. (4pts) Complete the missing information in this formulation to prepare 1 fluid ounce of 10% w/v hydrochloric acid solution. Recall that concentrated acids are typically expressed as w/w% concentrations and dilute acids as w/v% concentrations.
Rx for 10% Hydrochloric Acid Solution
Concentrated Hydrochloric Acid
_____ml (37.5% w/w; SG=1.18)
Purified Wate
qs 30ml
3. (4pts) The following is a formulation for a fever blister ointment.
Rx Tannic Acid 6%
Camphor 9%
Phenol 3%
Benzocaine 2%
Alcohol USP 3ml
Aquaphor® Ointment Base qs 100g
Your source of phenol is pictured here. The specific gravity of the solution is 1.07. How many milliliters of the phenol solution would you need to prepare 60g of the ointment?
4. (4pts) A local dermatologist would like you to prepare 1 pint of a potassium permanganate solution to be used as a wet soak for a patient’s abscess. The solution will be used to soak gauze that will be applied to the area for 20-30 minutes at a time. Calculate how many milligrams of potassium permanganate crystals you would need to prepare 1 pint of this solution.
Rx
Potassium Permanganate
1:10,000
Purified Water
qs 1 gallon
Weigh _____________ KMnO4 crystals on a torsion balance. (Round appropriately based on readability.)
qs to _____________________ml with purified water
Refer to your textbook Contemporary Pharmacy Practice & Compounding Chapter 15 Section V to answer the following questions.
5. (2pts) What is one example of a time that using a syringe to measure a liquid for nonsterile compounding is more convenient that using a graduated cylinder. Explain your answer.
6. (2pts) Explain why beakers are not recommended for volumetric measurement for nonsterile compounding.
7. (2pts) What is meant by “cali
ating” a beaker (a process that will allow the beaker to be a more accurate measuring device that if it were not cali
ated)?
8. (2pts) What is the author’s recommendation for measuring or qs’ing in a graduated prescription bottle (or oval)?
9. (3pts) What is the general rule of thumb for minimum measurable quantity in a graduated cylinder? Complete the following table using this rule.
Type of Device
Size
Cali
ation
(values must be rounded to the nearest)
Min Volume
Max Volume
Graduated Cylinders
5ml
0.1ml
5ml
10ml
1ml
10ml
50ml
1ml
50ml
100ml
1ml
100ml
250ml
1ml
250ml
10. (8pts) Calculate how many milliliters of each ingredient you would need to prepare 10 nystatin popsicles and indicate what size of graduated cylinder you would use to measure each ingredient, and what size of graduated cylinder you would use to qs to your final volume (with purified water). Round appropriately, if necessary (see table in previous question for cali
ation markings.)
Rx Nystatin 250,000 units frozen popsicles
For 30 popsicles
Nystatin 100,000 units/ml oral suspension
75ml
So
itol 70% w/w Oral Solution
60ml
Banana flavoring
5ml
Purified Water
qs 900ml
11. (3pts) In the previous formulation for nystatin popsicles, what is the w/v% concentration of the sweetener, so
itol? (SG of 70% w/w So
itol Solution = 1.285)
1