Essential Math and Calculations for Pharmacy Technicians

Indra K. Reddy, Mansoor A. Khan

Chapter 7 Working with Liquid Dosage Forms - all with Video Answers

Educators

Chapter Questions

Problem 1

What is the percentage of alcohol in the following prescription?
Tincture A $110 \mathrm{~mL}$ (35\% alcohol)
Tincture B $220 \mathrm{~mL}$ ( $25 \%$ alcohol)
Tincture C $330 \mathrm{~mL}$ (20\% alcohol)
Sig. $5 \mathrm{~mL}$ for cough.

Ian Maurer

Numerade Educator

02:54

Problem 2

What is the percentage strength $(\mathrm{v} / \mathrm{v})$ of alcohol in a mixture of $20 \mathrm{~mL}$ of $12 \% \mathrm{v} / \mathrm{v}$ alcohol, $15 \mathrm{~mL}$ of $18 \% \mathrm{v} / \mathrm{v}$ alcohol, and $25 \mathrm{~mL}$ of $25 \% \mathrm{v} / \mathrm{v}$ alcohol?

Debasish Das

Numerade Educator

02:54

Problem 3

What is the percentage strength $(\mathrm{v} / \mathrm{v})$ of alcohol in a mixture of $12 \mathrm{~mL}$ of $17 \% \mathrm{v} / \mathrm{v}$ alcohol, $10 \mathrm{~mL}$ of $50 \% \mathrm{v} / \mathrm{v}$ alcohol, and $500 \mathrm{~mL}$ of $33 \% \mathrm{v} / \mathrm{v}$ alcohol?

Debasish Das

Numerade Educator

01:14

Problem 4

What is the percentage strength $(\mathrm{v} / \mathrm{v})$ of alcohol in a mixture of $32 \mathrm{~mL}$ of $35 \% \mathrm{v} / \mathrm{v}$ alcohol, $22 \mathrm{~mL}$ of $37 \% \mathrm{v} / \mathrm{v}$ alcohol, and $11 \mathrm{~mL}$ of $28 \% \mathrm{v} / \mathrm{v}$ alcohol?

Lijeesh Krishnan

Numerade Educator

00:40

Problem 5

How many milliliters of a 1:250 v/v solution of diazepam in alcohol can be made from $100 \mathrm{~mL}$ of $2.5 \% \mathrm{v} / \mathrm{v}$ solution?

Alison Rodriguez

Numerade Educator

02:06

Problem 6

How many milliliters of a $1: 100 \mathrm{v} / \mathrm{v}$ solution of testosterone in alcohol can be made from $100 \mathrm{~mL}$ of $10 \% \mathrm{v} / \mathrm{v}$ solution?

Ankit Gupta

Numerade Educator

00:37

Problem 7

How many milliliters of a $1: 50 \mathrm{v} / \mathrm{v}$ solution of aspirin in alcohol can be made from $100 \mathrm{~mL}$ of $50 \% \mathrm{v} / \mathrm{v}$ solution?

David Collins

Numerade Educator

01:51

Problem 8

If $100 \mathrm{~mL}$ of a Choledyl ${ }^D$ elixir containing $10 \mathrm{mg} / 5 \mathrm{~mL}$ active ingredient (oxtriphylline) is diluted to $500 \mathrm{~mL}$, what will be the final strength of oxtriphylline?

David Collins

Numerade Educator

01:28

Problem 9

If $10 \mathrm{~mL}$ of an elixir containing $50 \mathrm{mg} / 10 \mathrm{~mL}$ active ingredient is diluted to $12 \mathrm{~mL}$, what will be the final strength of active ingredient?

David Collins

Numerade Educator

Problem 10

If $100 \mathrm{~mL}$ of an elixir containing $3 \mathrm{mg} / 5 \mathrm{~mL}$ theophylline is diluted to $150 \mathrm{~mL}$, what will be the final strength of theophylline?

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00:46

Problem 11

What is the percentage of alcohol in the following prescription?
Chloroform spirit $\quad 110.0 \mathrm{~mL}(88 \%$ alcohol)
Aromatic elixir $\quad 85.0 \mathrm{~mL}(22 \%$ alcohol $)$
Terpin hydrate elixir $255.0 \mathrm{~mL}$ ( $40 \%$ alcohol)
Sig. $5 \mathrm{~mL}$ for cough.

Kristen Karbon

Numerade Educator

01:14

Problem 12

What is the percentage strength $(\mathrm{v} / \mathrm{v})$ of alcohol in a mixture of $200 \mathrm{~mL}$ of $12 \% \mathrm{v} / \mathrm{v}$ alcohol, $150 \mathrm{~mL}$ of $18 \% \mathrm{v} / \mathrm{v}$ alcohol, and $250 \mathrm{~mL}$ of $25 \% \mathrm{v} / \mathrm{v}$ alcohol?

Lijeesh Krishnan

Numerade Educator

01:11

Problem 13

How many milliliters of a $1: 500 \mathrm{v} / \mathrm{v}$ solution of methyl salicylate in alcohol can be made from $100 \mathrm{~mL}$ of $5 \% \mathrm{v} / \mathrm{v}$ solution?

David Collins

Numerade Educator

01:51

Problem 14

If $50 \mathrm{~mL}$ of a Choledyl ${ }^{\circledR}$ elixir containing $100 \mathrm{mg} / 5 \mathrm{~mL}$ active ingredient (oxtriphylline) is diluted to $250 \mathrm{~mL}$, what will be the final strength of oxtriphylline?

David Collins

Numerade Educator

00:30

Problem 15

How many milliliters of phenobarbital elixirs containing $20 \mathrm{mg}$ per $5 \mathrm{~mL}$ and $30 \mathrm{mg}$ per $5 \mathrm{~mL}$ should be used in preparing a liter of phenobarbital elixir containing $4.8 \mathrm{mg}$ of phenobarbital per $\mathrm{mL}$ ?

Ronald Prasad

Numerade Educator

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Problem 16

How many milliliters of methenamine mandelate oral suspensions containing $250 \mathrm{mg}$ and $500 \mathrm{mg}$ per $5 \mathrm{~mL}$ should be used in preparing a liter of a suspension containing $60 \mathrm{mg}$ of methenamine mandelate per $\mathrm{mL}$ ?

Gayathri Janakiraman Paramasivan

Numerade Educator

01:07

Problem 17

How many milliliters of griseofulvin oral suspensions containing $100 \mathrm{mg}$ and $125 \mathrm{mg}$ per $\mathrm{mL}$ should be used in preparing $100 \mathrm{~mL}$ of a suspension containing $12 \%$ of griseofulvin?

David Collins

Numerade Educator

Problem 18

A physician order calls for a theophylline oral suspension to contain 100 $\mathrm{mg}$ of theophylline in $5 \mathrm{~mL}$ of aqueous vehicle. The pharmacist has on hand a $4.5 \%$ aqueous suspension of theophylline. How many $\mathrm{mL}$ of aqueous vehicle should be added to the preparation on hand in preparing the prescribed suspension?

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03:00

Problem 19

What is the percentage of alcohol in the following prescription?
Tincture iodine $\quad 10 \mathrm{~mL}(40 \%$ alcohol $)$
Aromatic elixir $\quad 20 \mathrm{~mL}(56 \%$ alcohol $)$
Terpin hydrate elixir $30 \mathrm{~mL}$ ( $4 \%$ alcohol)
Sig. $5 \mathrm{~mL}$ for cough.

Catherine Lemar

Numerade Educator

00:46

Problem 20

What is the percentage of alcohol in the following prescription?
Spirit $\quad 120 \mathrm{~mL}(20 \%$ alcohol $)$
Elixir A $\quad 432 \mathrm{~mL}(60 \%$ alcohol)
Elixir B $\quad 345 \mathrm{~mL}$ (20\% alcohol)
Sig. $5 \mathrm{~mL}$ for cold

Kristen Karbon

Numerade Educator

02:32

Problem 21

How many milliliters of ketamine elixirs containing $40 \mathrm{mg}$ per $5 \mathrm{~mL}$ and $60 \mathrm{mg}$ per $5 \mathrm{~mL}$ should be used in preparing a liter of ketamine elixir containing $9.6 \mathrm{mg}$ of ketamine per $\mathrm{mL}$ ?

Dharmendra Jain

Numerade Educator

Problem 22

How many milliliters of digoxin elixirs containing $10 \mathrm{mg}$ per $5 \mathrm{~mL}$ and $15 \mathrm{mg}$ per $5 \mathrm{~mL}$ should be used in preparing $500 \mathrm{~mL}$ of digoxin elixir containing $2.4 \mathrm{mg}$ of digoxin per $\mathrm{mL}$ ?

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06:56

Problem 23

How many milliliters of ranitidine elixirs containing $12 \mathrm{mg}$ per $10 \mathrm{~mL}$ and $32 \mathrm{mg}$ per $5 \mathrm{~mL}$ should be used in preparing 3 liters of ranitidine elixir containing $5 \mathrm{mg}$ of ranitidine per $\mathrm{mL}$ ?

Joy Carpio

Numerade Educator

Problem 24

How many milliliters of calcium oral suspensions containing $300 \mathrm{mg}$ and $450 \mathrm{mg}$ per $5 \mathrm{~mL}$ should be used in preparing 2 liters of a suspension containing $70 \mathrm{mg}$ of calcium per $\mathrm{mL}$ ?

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04:38

Problem 25

How many milliliters of barium oral suspensions containing $250 \mathrm{mg}$ and $500 \mathrm{mg}$ per $5 \mathrm{~mL}$ should be used in preparing $500 \mathrm{~mL}$ of a suspension containing $55 \mathrm{mg}$ of barium per $\mathrm{mL}$ ?

Mehrnaz Siavoshi

Numerade Educator

Problem 26

How many milliliters of calcitonin nasal solution containing $2.5 \mathrm{mg}$ per $5 \mathrm{~mL}$ and $5 \mathrm{mg}$ per $\mathrm{mL}$ should be used in preparing $200 \mathrm{~mL}$ of a solution containing $1 \mathrm{mg}$ of calcitonin per $\mathrm{mL}$ ?

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Problem 27

How many milliliters of taxol suspensions containing $50 \mathrm{mg}$ and $65 \mathrm{mg}$ per $\mathrm{mL}$ should be used in preparing $50 \mathrm{~mL}$ of a suspension containing $6 \%$ of taxol?

Gayathri Janakiraman Paramasivan

Numerade Educator

03:17

Problem 28

How many milliliters of EDTA solution containing $150 \mathrm{mg}$ and $175 \mathrm{mg}$ per $\mathrm{mL}$ should be used in preparing $150 \mathrm{~mL}$ of a solution containing $16 \%$ of EDTA?

Carolina Acevedo

Numerade Educator

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Problem 29

How many milliliters of methotraxate suspensions containing $260 \mathrm{mg}$ and $400 \mathrm{mg}$ per $\mathrm{mL}$ should be used in preparing $1000 \mathrm{~mL}$ of a suspension containing $30 \%$ of methotraxate?

Gayathri Janakiraman Paramasivan

Numerade Educator

Problem 30

A physician order calls for a ketoprofen oral suspension to contain $50 \mathrm{mg}$ of ketoprofen in $5 \mathrm{~mL}$ of aqueous vehicle. The pharmacist has on hand a $1.5 \%$ aqueous suspension of ketoprofen. How many $\mathrm{mL}$ of aqueous vehicle should be added to the preparation on hand in preparing the prescribed suspension?

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