Chapter 10: Calc II, Compounding Flashcards by Saina Karami

What are the types of percentage concentrations used in Percentage Strength?

Weight-in-Volume [%W/V] = g/100 ml
Volume-in-Volume [%V/V] = ml/100 ml
Weight-in-Weight [%W/W] = g/100 g

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How many grams of NaCl are in 1 Liter of Normal Saline [NS]?

9 g

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How many grams of NaCl are in 500ml of 1/2 NS? Round to the nearest hundredth.

2.25 g

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How many milligrams of triamcinolone should be used in preparing the following prescription? Round to the nearest whole number.
Triaminolone [w/v] = 5%
Glycerin qs = 60 mL
Sig: Two drops in right ear once daily

3 g

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How many grams of Dextrose are in 250 ml of D5W? Round to the nearest tenth?

12.5 g

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A prescription reads as follows: “Prepare a 3% w/w coal tar preparation; qs with petrolatum to 150 grams.” How many grams of Petrolatum are required to compound the prescription? Round to the nearest tenth.

145.5 g petrolatum

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What is the final percentage strength of the compounded product [w/v] when reconstituting a 5 g vial of vancomycin powder for injection with 50 ml of sterile water, then diluting with sterile water to 200 ml?

2.5 g / 100 mL OR 2.5%

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If 1,250 grams of a mixture contains 80 grams of a drug, what is the percentage strength [w/w] of the mixture? Round to the nearest tenths.

6.4 g / 100 g OR 6.4%

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A mouth rinse contains 1/12 % w/v of Chlorhexidine Gluconate. How many grams of Chlorhexidine Gluconate should be used to prepare 18 Liters of mouth rinse? Round to the nearest whole number.

15 g

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What is the maximum milligrams of pilocarpine a 79 year old female will receive per day if the prescription is Pilocarpine = 1% w/v, Sodium Chloride qs ad = 15 ml, Sig: 2 gtts [0.05 ml/gtt] po TID prn up to 5 days for Dry Mouth?

3 mg

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What is the percentage strength [w/v] of metronidazole in a prescription where 6 tablets, each containing 250 mg, are dissolved in a liquid base to prepare 60 ml of a topical solution? Round to the nearest tenth.

2.5 g / 100 mL OR 2.5%

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If 12 grams of Lanolin are combined with 2 grams of white wax and 36 grams of petrolatum to make an ointment, what is the percentage strength [w/w] of lanolin in the ointment?

24 g / 100 g OR 24%

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A pharmacist adds 5.3 grams of hydrocortisone to 150 grams of a 2.5% hydrocortisone ointment. What is the percentage strength [w/w] of hydrocortisone in the finished product? Round to the nearest whole number.

6 g / 100 g OR 6%

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How many milliliters of hydrocortisone liquid [40 mg/mL] will be needed to prepare 30 grams of a 0.25% cream [w/w]? Round to the nearest hundredth.

1.88 mL

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What is the percentage strength of imiquimod in the following prescription? Round to the nearest hundredth.
Imiquimod 5% cream = 15 g
Xylocaine = 20 g
Hydrophilic Ointment = 25 g

1.25 g / 100 g OR 1.25%

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How is Ratio Strength denoted?

One unit of solute in the total amount

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What is the “shortcut” method for Ratio Strength?

Ratio –> %: % strength = 100 / Ratio
% –> Ratio: Ratio = 100 / %

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Express 0.04% as a ratio strength.

1:2500

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Express 1:4000 as a percentage strength.

0.025 / 100 OR 0.025%

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There are 50 mg of a drug in 50 ml of a solution. Express the concentration as a ratio strength.

1:1000

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How many milligrams of iodine should be used in compounding the following prescription?
Iodine = 1:400
Hydrophilic Ointment qs ad = 10 g
Sig: Apply as directed

25 g Iodine

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A 10 ml mixture contains 0.25 ml of active drug. Express the concentration as percentage strength [v/v] and ratio strength.

2.5 ml / 100 ml OR 2.5%
1:40

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What is the Concentration, in ratio strength, of a trituration made by combining 150 mg of albuterol sulfate and 4.05 grams of lactose?

1:28

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What does it mean to express something in Parts Per Million [or billion]?

Expresses VERY dilute solutions - parts of drug per 1 million [or 1 billion] parts of the whole

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What is the “Shortcut” method for finding PPM?

PPM –> %: move decimal to LEFT 4 spaces % –> PPM: move decimal to RIGHT 4 spaces

Express 0.00022% [w/v] as PPM. Round to the nearest tenth.

2.2 PPM

Express 30 PPM of copper in solution as a percentage.

0.003%

Express 5 PPM of iron in water as a percentage.

0.0005%

A patient's blood contains 0.085 PPM of selenium. How many micrograms of selenium does the patient's blood contain if the blood volume is 6 Liters?

510 mcg

A sample of an intravenous solution is found to contain 0.4 PPM of DEHP. How much of the solution, in milliliters, will contain 50 micrograms of DEHP?

125 ml

What is Specific Gravity?

Ratio of the density of a substance to the density of water.

What is the specific gravity of water?

1 g; 1 g of water = 1 ml water.

What is the specific gravity of 150 ml of glycerin weighing 165 grams?

1.1

What is the weight of 750 ml of concentrated acetic acid [SG = 1.2]?

900 g

How many milliliters of polysorbate 80 [SG = 1.08] are needed to prepare a prescription that includes 48 grams of the surfactant/emulsifier (polysorbate)?

44.44 ml

What is the specific gravity of 30 ml of a liquid weighing 23,400 milligrams?

0.78

What is the weight of 0.5 L of polyethylene glycol 400 [SG = 1.13]?

565 g

What is the weight of one quart of nitroglycerin with a specific gravity of 1.59?

1504 g

How many milliliters of D50% will provide an equivalent energy requirement for 550 ml of D70%?

770 mL

How many grams of petrolatum should be added to 250 grams of 20% ichthammol ointment to make a 7% ichthammol ointment?

464.3 g

How many milliliters of bacteriostatic water should be added to reduce a 200 ml enteral mixture from 432 mOsm/L to 278 mOsm/L?

111 ml

If 1 gallon of a 20% [w/v] solution is evaporated to a solution with 50% [w/v] strength, what will be the new volume?

1500 ml

How much diluent is required to manufacture a 5% ointment from 20 grams of a 9% boric acid ointment base?

16 g

How many grams of the 16% and 12% ichthammol ointments are required to prepare 80 grams of a 12.5% ichthammol ointment?

10 g of the 16% 70 g of the 12%

How many milliliters of the 3% and 8.5% iodine tincture should be used to prepare 1 gallon of tincture containing 5.5% iodine?

1720 ml of 8.5% 2065 ml of 3%

A hospice pharmacist receives a prescription for 1% morphine sulfate oral solution. She has a 120 mL bottle of morphine sulfate labeled 20 mg/5 mL and a 240 mL bottle of morphine sulfate labeled 100 mg/5 mL. How much of the 100 mg/5 mL product must be mixed with the contents of the 20 mg/5 mL morphine sulfate bottle to prepare the desired percentage strength for the patient?

72 ml

How much of each 25% and 75% powder is required to prepare 100 grams of a 50% hydrocortisone powder?

50 g of both 25% and 75%

What is osmolarity?

Total number of particles per liter of solution.

What compounds are dissociated by 1 particle for Osmolarity?

Dextrose Mannitol

What compounds are dissociated by 2 particles for Osmolarity?

Potassium Chloride Sodium Chloride Sodium Acetate Magnesium Sulfate

What compounds are dissociated by 3 particles for Osmolarity?

Calcium Chloride Sodium Citrate

What is the equation for osmolarity?

(Weight [g/L] / MW [g/mole]) x (# of particles) x 1000 ## Footnote Step 1: add up the number of particles Step 2: calculate the number of grams of the compound in 1 L Step 3: Use the molecular weight [MW]

What is the osmolarity, in mOsm/L, of normal saline [0.9% NaCl]?

308 mOsmol/L

What is the osmolarity, in mOsm/L, of D5W?

252.5 mOsmol/L

How many milliosmoles of CaCl2 (MW=111) are represented in 150 mL of a 10% [w/v] calcium chloride solution?

405 mOsmol/L

A solution contains 373 mg of Na ions per liter. How many milliosmoles are represented in the solution? (MW=23 g/mole)

16.2 mOsmol/L

How many grams of Potassium Chloride are needed to make 200 ml of a solution containing 250 mOsmol/L? K (MW=39g/mole), Cl (MW=35.5 g/mole)

1.86 g

A solution contains 200 mg of Ca ions per liter. How many milliosmoles are represented in the solution? Ca (MW=40 g/mole)

5 mOsmol/L

Calculate the osmolar concentration, in milliosmoles, represented by 1 liter of a 10% [w/v] solution of anhydrous dextrose (MW=180 g/mole).

555.6 mOsmol/L

patient was ordered 1 liter of D5NS with 20 mEq of KCl for dehydration. How many milliosmoles are in 1 liter of this fluid (MW dextrose = 198 g/mol, Na = 23 g/mol, K = 39 g/mol, Cl = 35.5 g/mol)? Round to the nearest whole number.

600 mOsmol/L

Calculate the E value for Mannitol [MW = 182 g/mol]. Round to the nearest hundredth.

0.18

What is the equation for finding the E value?

E = ((58.5)(i))/((MW)(1.8))

The E value for ephedrine sulfate is 0.23. How many grams of sodium chloride are needed to compound the following prescription? Round to 3 decimal places. Ephedrine Sulfate = 0.4 g Sodium Chloride = qs Purified Water qs = 30 mL Make isotonic soln. Sig: Use 2 drops in each nostril as directed

0.178 g of NaCl are needed

Calculate the E value for Potassium Iodide, which dissociates into 2 particles [MW = 166 g/mol]. Round to two decimal places.

0.35

Physostigmine Salicyclate [MW = 413 g/mol] is a 2-ion electrolyte, dissociating 80% in a given concentration [i.e., use a dissociation factor of 1.8]. Calculate its sodium chloride equivalent. Round to two decimal places.

0.14

The pharmacist receives an order for 10 ml of tobramycin 1% ophthalmic solution. He has tobramycin 40 mg/mL solution. Tobramycin does not dissociate and has a MW = 468 g/mol. Find the E value for tobramycin and determine how many milligrams of NaCl are needed to make the solution isotonic?

83 mg

What are the equations used for finding moles?

mols = g / MW

How many moles of anhydrous magnesium sulfate [MW = 120.4 g/mol] are present in 250 grams of the substance? Round to the nearest hundredth.

2.08 mols

How many moles equivalent to 875 milligrams of aluminum acetate [MW = 204 g/mol]? Round to 3 decimal places.

0.004 mols

How many millimoles of sodium phosphate [MW = 138 g/mol] are present in 90 g of the substance? Round to the nearest whole number.

0.652 mols –> 652 mmols

How many moles are equivalent to 45 grams of potassium carbonate [MW = 138 g/mol]? Round to the nearest thousandth.

0.326 mols

How many millimoles of calcium chloride [MW = 147 g/mol] are represented in 147 ml of a 10% [w/v] calcium chloride solution?

100 mmols

How many milligrams of sodium chloride [MW= 58.5 g/mol] represent 0.25 mmol? Do not round the answer.

14.625 mg

How many grams of sodium chloride [MW = 58.5 g/mol] should be used to prepare this solution? Do not round the answer. Methylprednisolone = 0.5 g NaCl solution = 60 mL Each 5 ml should contain 0.6 mmols of NaCl.

0.4212 g NaCl

Which common compounds have 1 valence?

Ammonium Chloride Potassium Chloride Potassium Gluconate Sodium Acetate Sodium Bicarbonate Sodium Chloride

Which common compounds have 2 valence?

Calcium Carbonate Calcium Chloride Ferrous Sulfate Lithium Carbonate Magnesium Sulfate

What is the Equation for finding milliequivalents?

mEq = (mg x valence) / MW

A 20 ml vial is labeled potassium chloride [2 mEq/ml]. How many grams of potassium chloride [MW = 74.5 g/mol] are present? Round to the nearest hundredths.

2.98 g

How many milliequivalents of potassium chloride are present in a 12 ml dose of a 10% [w/v] potassium chloride [MW = 74.5 g/mol] elixir? Round to 1 decimal place.

16.1 mEq

Calculate the milliequivalents of a standard ammonium chloride [MW = 53.5 g/mol] 21.4 mg/mL sterile solution in a 500 ml container?

200 mEq

How many milliequivalents of MgSO4 [MW = 120.4 g/mol] are represented in 1 gram of anhydrous magnesium sulfate? Round to the nearest tenth.

16.6 mEq

How many milliequivalents of sodium are in a 50 mL of 8.4% sodium Bicarbonate [MW = 84 g/mol]?

50 mEq

A 74 year old male takes Lithobid (lithium carbonate, Li2CO3) 450 mg po BID, but reports difficulty swallowing the capsules. How many milliliters of lithium citrate syrup provide an equivalent daily dose of lithium? Round to the nearest whole number. [MW of Lithium Carbonate = 74 g/mol]

15 ml of lithium citrate per day

Chapter 10: Calc II, Compounding Flashcards

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