Chapter 16 (Compounding II: Equipment, Stability, Excipients)
A pharmacist receives an order for D10W to infuse at 45 mL/hour. The pharmacy has only D50W and sterile water available, due to a purchasing miscommunication. How many milliliters of D50W should be added to one liter of sterile water to make D10W? (Answer must be numeric; no commas or units; round the final answer to the nearest WHOLE number.)
250
How many milligrams of sodium hydroxide (MW = 40) are represented by 0.25 mmol? (Answer must be numeric; no units or commas; round the final answer to the nearest WHOLE number.)
10
How many milligrams of potassium chloride are present in 12 mEq of potassium chloride? (M.W. = 74.5) (Answer must be numeric; no units or commas; round the final answer to the nearest WHOLE number.)
894
A prefilled syringe contains 50 mg of phenylephrine hydrochloride per 5 mL of injection. What is the percentage concentration (w/v) of phenylephrine in the injection. (Answer must be numeric; no units or commas; round the final answer to the nearest WHOLE number.)
1
If 500 mL of a 28% (v/v) solution of methyl salicylate are diluted to a 2 liter solution, what is the percentage strength (v/v) of the new product? (Answer must be numeric; no units or commas; round the final answer to the nearest WHOLE number.)
7
A pharmacist receives the following prescription:
Rx:
Triamcinolone (w/v) 5%
Glycerin qs ad 10
mL
Sig: One drop in each ear daily
How many grams of triamcinolone should be used in preparing the
prescription? (Answer must be numeric; no units or commas; include a
leading zero when the answer is less than 1; round the final answer to
the nearest TENTH.)
0.5
A 10 mL vial is labeled "potassium chloride (2 mEq/mL)". How many grams of potassium chloride are contained in the vial? (M.W. of KCl = 74.5) (Answer must be numeric; no units or commas; include a leading zero when the answer is less than 1; round the final answer to the nearest TWO DECIMAL PLACES.)
1.49
How many grams of NaCl are in 500 mL of 1/2 NS? (Answer must be numeric; no units or commas; include a leading zero when the answer is less than 1; round the final answer to the nearest HUNDREDTH.)
2.25
A pharmacist has a prescription for a compounded 1% hydrocortisone cream. She will add 2.5% hydrocortisone cream to 112 grams of 0.25% hydrocortisone cream to prepare the 1% cream. The 2.5% cream and the 0.25% cream should be mixed in a ratio of 1 part 2.5% cream to how many parts of 0.25% cream? (Answer must be numeric; no units or commas; round the final answer to the nearest WHOLE number.)
2
Once the number of parts of each product have been determined by alligation (0.75 parts of 2.5% and 1.5 parts of 0.25%), reduce this fraction to get the ratio: 1.5 parts/0.75 parts = 2. You have determined that 2 parts of the 0.25% product must be mixed with 1 part of the 2.5% product to get a 1% cream.
Express 450 parts per million (PPM) as a percentage. (Answer must be numeric; no units or commas; include a leading zero when the answer is less than 1; round the final answer to the nearest TWO DECIMAL PLACES.)
0.05
How many milliliters of bacteriostatic water should be added to the 600 mL of TwoCal HN to match the osmolarity of Osmolite 1.0? (Answer must be numeric; no units or commas; round the final answer to the nearest WHOLE number.)
850
Express 0.00088% w/v as parts per million (PPM):
8.8 PPM
How many grams of sodium acetate (MW = 82) should be added to the PN? (Answer must be numeric; no units or commas; round the final answer to the nearest TENTH.)
1.3
A pharmacist working in pediatrics receives several orders for a 5% sodium chloride inhalation from a physician who is new to the hospital. The pharmacy does not stock this strength. The pharmacist has 250 mL bags of 1/2NS and 20 mL vials of 14.6% sodium chloride. How many milliliters of the 14.6% sodium chloride must be mixed with the 250 mL bag of 1/2NS to prepare the 5% sodium chloride that was ordered? (Answer must be numeric; no units or commas; round the final answer to the nearest TENTH.)
118.5
What is the specific gravity of 75 mL of clove oil weighing 78 grams? (Answer must be numeric; no units or commas; include a leading zero when the answer is less than 1; round the final answer to the nearest HUNDREDTH.)
1.04
A pharmacy technician added 10 mL of a 20% (w/v) solution of potassium chloride to a 500 mL bag of normal saline. What is the percentage strength of potassium chloride in the bag? (Answer must be numeric; no units or commas; include a leading zero when the answer is less than 1; round the final answer to the nearest HUNDREDTH.)
0.39
20 g / 100 mL = X g / 10 mLX = 2 grams
The technician
added 10 mL to a 500 mL bag, so the total volume is
510 mL.2 g / 510 mL = X g / 100 mL0.39 g or 0.39%
If a solution contains 20 g of glycerol and 5 g of codeine, what is the codeine percentage strength (w/w) of the solution? (Answer must be numeric; no units or commas; round the final answer to the nearest WHOLE number.)
20
Percentage strength is a ratio of the amount of an ingredient to the amount of the product. 5 g codeine/25 g total = X/100 = 20 g (20% w/w).
New Orders:Nothing by mouth
Cubicin 6 mg/kg IV dailyDiscontinue IV fluids
Start TPN:
1,800 mL D20W, 750 mL FreAmine 8.5%, 250 mL
Intralipid 20%, 50 mL of electrolytes/minerals
The pharmacist will use 15% FreAmine to compound the TPN. How many milliliters will be required? (Answer must be numeric; no units or commas; round the final answer to the nearest WHOLE number.)
425
The pharmacy has D70W and D10W in stock. How many milliliters of D70W are needed to prepare the volume and strength of dextrose ordered for the TPN? (Answer must be numeric; no units or commas; round the final answer to the nearest WHOLE number.)
300
If the pharmacy technician preparing the compound injects 15 mL of the reconstituted Herceptin solution (21 mg/mL) into the 250 mL of 0.9% sodium chloride, what is the percentage strength of Herceptin in the final product? (Answer must be numeric; no units or commas; include a leading zero for answers less than 1; round the final answer to the nearest HUNDREDTH.)
0.12
A prescriber orders 500 mL of a 1:400 acetic acid bladder irrigation for a patient. How many milliliters of a 1.5% stock solution of acetic acid are needed to prepare the bladder irrigation? (Answer must be numeric; no units or commas; round the final answer to the nearest WHOLE number.)
83
How many milliliters of capsaicin liquid (50 mg/mL) are required to prepare 42.5 grams of a 0.15% (w/w) cream? (Answer must be numeric; no units or commas; include a leading zero when the answer is less than 1; round the final answer to the nearest TENTH.)
1.3
First, determine how many milligrams of capsaicin are needed to make
42.5 grams of a 0.15% (w/w) cream:0.15 g/100 g = x g/42.5 gx = 0.06375
g (or 63.75 mg)
Next, determine how many milliliters of the 50
mg/mL product will supply 63.75 mg:63.75 mg/x mL = 50 mg/1 mLx = 1.275
mL, rounded to 1.3 per the instructions
A dexamethasone elixir contains 0.5 mg dexamethasone per 5 mL. What is the percentage strength (w/v) of the dexamethasone elixir in this prescription? (Answer must be numeric; no units or commas; include a leading zero when the answer is less than 1; round the final answer to the nearest HUNDREDTH.)
0.01
What is the osmolarity, in mOsm/L, of 3% NaCl? (M.W. = 58.5). (Answer must be numeric; no units or commas; round the final answer to the nearest WHOLE number.)
1026
A pharmacist is adding 260 milliliters of dextrose 70% to a parenteral nutrition admixture. How many kcals will the dextrose provide? (Answer must be numeric; no units or commas; round the final answer to the nearest WHOLE number.)
619
LK is a female patient being treated for pneumonia with sepsis in the
ICU.
Physical Exam / Vitals:
Age: 68 years
Height: 5'7", Weight: 198 lbs
BP:
118/73 mmHg, HR: 95 BPM
How many mEq/kg IBW/day of sodium chloride did LK receive from her maintenance fluid on February 7th (MW NaCl = 58.5)? (Answer must be numeric; no units or commas; include a leading zero if the answer is less than 1; round the final answer to the nearest TENTH.)
2.2
How many moles are equivalent to 290 mg of aluminum hydroxide? (M.W. = 78). (Answer must be numeric; no units or commas; include a leading zero when the answer is less than 1; round the final answer to THREE DECIMAL PLACES.)
0.004
Hospital Medications:
Cefazolin 2 g IV x 1 preoperatively
D5NS continuously at 125 mL/hr
Morphine PCA bolus dose: 0.5 mg IV Q10 minutes PRN; Max: 2.5 mg per hour
Diphenhydramine 25 mg PO Q4H PRN itching
Magnesium oxide 400 mg PO TID x 3 days
How many milliequivalents of magnesium is DL receiving daily to correct his serum magnesium level (M.W. MgO = 40.3)? (Answer must be numeric; no units or commas; round the final answer to the nearest WHOLE number.)
60
What is the osmolarity (mOsm/L) of the intravenous fluids ordered for DL? (MW of dextrose = 198; MW of Na = 23; MW of Cl = 35.5) (Answer must be numeric; no units or commas; round the final answer to the nearest WHOLE number.)
560
The pharmacist needs to prepare 35 grams of a 70% powder using the 50% and 90% powders he has in stock. How much of each powder is required?
17.5 grams of the 50% and 17.5 grams of the 90%
BL is a nine-year-old African American who is hospitalized with acute sickle cell crisis. The pharmacist is preparing intravenous fluids for this patient. She adds 2 grams of potassium chloride to 1 L of D5W/1/2 normal saline. What is the estimated osmolarity per liter (mOsm/L) of this solution assuming the final volume is 1 L (MW of sodium = 23, potassium = 39, chloride = 35.5 and dextrose is 198)?
460
To solve the problem calculate the contribution of each component and add them together: for example, for KCl: 2 grams รท 74.5 = 0.0268 mol or 26.8 mmols x 2 particles is 53.6. Calculate for the dextrose and the sodium and then add together. The problem asked per liter.
A pharmacist receives an order for 5% sodium chloride inhalation Q6H for a patient with cystic fibrosis. The pharmacy does not stock this strength but has 250 mL bags of 1/2NS and 20 mL vials of 23.4% sodium chloride. How many milliliters of the 23.4% sodium chloride must be mixed with the contents of 1 bag of 1/2NS to prepare the 5% sodium chloride that was ordered? (Answer must be numeric; no units or commas; round the final answer to the nearest TENTH.)
61.8
If 1 gallon of a 15% (w/v) solution is evaporated to a solution with a 40% (w/v) strength, what is the new volume in milliliters? Use 1 gallon = 3,785 mL. (Answer must be numeric; no units or commas; round the final answer to the nearest WHOLE number.)
1419
The pharmacy has an order for 10 mL of tobramycin 1% ophthalmic solution. The pharmacy has tobramycin 40 mg/mL solution in stock. Tobramycin has a M.W. of 468 and does not dissociate. NaCl has a M.W. of 58.5 and a dissociation factor of 1.8. What is the equivalent value (the "E value") of tobramycin? (Answer must be numeric; no units or commas; include a leading zero when the answer is less than 1; round the final answer to TWO DECIMAL PLACES.)
0.07
A one-ounce bottle is labeled to contain 0.66 mL of the active drug. What is the ratio strength (v/v) of this solution? (Answer must be numeric; no units or commas; do not enter the 1 and the colon; enter only the number after the colon, as shown here with Xs: 1:XXX; round the final answer to the nearest WHOLE number.)
45
SP is a 79-year-old Caucasian male with newly diagnosed lung cancer.
Dietary Note:
Jevity 1.5 1,000 mLStart @ 10 mL/hr via NG tube, advance by
10 mL/hr every 6 hours if no residuals. Goal rate to meet nutrition
needs: 40 mL/hr.
How many milligrams of sodium (M.W. = 23) are contained in each
milliliter of the tube feed formula? (Answer must be numeric; no units
or commas; round the final answer to the nearest TENTH.)
1.4
SP is a 79-year-old Caucasian male with newly diagnosed lung cancer.
Dietary Note:
Jevity 1.5 1,000 mLStart @ 10 mL/hr via NG tube, advance by
10 mL/hr every 6 hours if no residuals. Goal rate to meet nutrition
needs: 40 mL/hr.
A few days later, the dietician recommends reducing the osmolarity of SP's tube feeds to 356 mOsm/L by adding purified water to the formula. How many milliliters of water will be required? (Answer must be numeric; no units or commas, round the final answer to the nearest WHOLE number.)
455
A pharmacist is preparing a 1.25% hydrocortisone ointment from commercially available 2% ointment and petrolatum (as a diluent). How many grams of petrolatum should be added to 12 grams of the 2% ointment to prepare the 1.25% strength? (Answer must be numeric; no units or commas; include a leading zero if the answer is less than 1; round the final answer to the nearest TENTH.)
7.2
Express 1:1500 as a percentage strength. (Answer must be numeric; no units or commas; include a leading zero when the answer is less than 1; round the final answer to the nearest THOUSANDTH.)
0.067
A pharmacist has an order for parenteral nutrition that includes 1000 mL of D70%. The pharmacist checks the supplies and finds the closest available strength is D50%. How many milliliters of D50% will provide an equivalent energy requirement?
1400
1000 mL (70%) = X mL (50%)