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 correct.

(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).

The density of sorbitol 70% w/w solution is 1.285g/ml. What is the concentration of sorbitol in the solution, expressed as a w/v% concentration?

Try the same calculation, but instead of using the SG of the sorbitol solution, use the density of sorbitol powder (1.49g/ml) to convert sorbitol 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!)

(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.

(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?

(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.

qs to _____________________ml with purified water

Refer to your textbook Contemporary Pharmacy Practice & Compounding Chapter 15 Section V to answer the following questions.

(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.

(2pts) Explain why beakers are not recommended for volumetric measurement for nonsterile compounding.

(2pts) What is meant by “calibrating” a beaker (a process that will allow the beaker to be a more accurate measuring device that if it were not calibrated)?

(2pts) What is the author’s recommendation for measuring or qs’ing in a graduated prescription bottle (or oval)?

(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	Calibration (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

(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 calibration markings.)

(3pts) In the previous formulation for nystatin popsicles, what is the w/v% concentration of the sweetener, sorbitol? (SG of 70% w/w Sorbitol Solution = 1.285)