Calculations of Percentage Strength (mg %W/V, mg%W/W) – PST04105 Pharmaceutical Calculations

By /
NTA Level 4 • Semester 1 • PST04105

Calculations of Percentage Strength (mg %W/V, mg%W/W)

Pharmaceutical Calculations • Source Session/Topic 15
Full source-text version: all educational wording from the extracted learning source is retained; only presenter/tutor metadata and web-layout noise are removed, while formatting is improved for readability.
Session 15: Calculations of Percentage Strength (mg %W/V, mg%W/W)

Total Session Time: 120 minutes

Prerequisites

• None

Learning Tasks

By the end of this session students are expected to be able to:

• Calculating the amount of a product/active ingredient from a given
percentage mg% w/v
• Calculating the amount of a product/active ingredient from a given
percentage mg% w/w

Resources Needed:

• Flip charts, marker pens, and masking tape
• Black/white board and chalk/whiteboard markers

SESSION OVERVIEW

|Step |Time |Activity/ |Content |

| | |Method | |

|1 |05 minutes |Presentation |Introduction, Learning Tasks |

|2 |50 minutes |Presentation |Amount of aProduct/Active Ingredient|

| | | |From a Given Percentage Mg %W/V |

|3 |50 minutes |Presentation |Amount of aProduct/Active Ingredient|

| | |Group |From a Given Percentage Mg %W/W |

| | |discussion | |

|4 |05 minutes |Presentation |Key Points |

| 5 |10 minutes |Presentation |Evaluation |

SESSION CONTENTS

STEP 1: Presentation of Session Title and Learning Tasks (5 minutes)

READ or ASK students to read the learning tasks and clarify

ASK students if they have any questions before continuing.

STEP 2: Amount of a Product/Active Ingredient From a Given Percentage Mg

%W/V (50 minutes)

• The term milligrams percent w/v (mg %w/v) expresses the number of

milligrams of a substance in 100mL of a liquid

• It is used to frequently to donate the concentration of a drug or natural

substances in a biological fluid, as in the blood.

o For example: 30mg% non protein nitrogen, means that each 100 mL
of blood contains 30 mg of non protein nitrogen

|Activity: Small Group Discussion (20 minutes) |

| |

|DIVIDE students into small manageable groups |

| |

|ASK students to discuss on the following question |

|Calculate the amount of drug required to prepare 500 mL of 1000 mg% w/v|

|solution? |

| |

|ALLOW students to discuss for 15 minutes |

| |

|ALLOW few groups to present and the rest to add points not mentioned |

| |

|CLARIFY and SUMMARIZE by using the contents below |

• The following is the answer for the above exercise:

The amount of drug will be calculated as

1000mg = 100ml
Xmg = 500ml
X = 1000mg x 500ml/100ml
X = 5000mg
X =5000mg, answer

STEP 3: Amount of a Product/Active Ingredient From a Given Percentage Mg

%W/W (50 minutes)

• The term milligrams percent w/w (mg %w/w) expresses the number of

milligrams of a substance in 100 gm of a product

o For example: 500mg%w/w benzoic acid ointment, means that each 100
gm of the ointment it contains 500 mg of benzoic acid

|Activity: Small Group Discussion ( 20 minutes) |

| |

|DIVIDE students into small manageable groups |

| |

|ASK students to discuss on the following question |

|Calculate the amount of phenol which should be used to prepare 240gm of|

|5000 mg% w/w solution? |

| |

|ALLOW students to discuss for 15 minutes |

| |

|ALLOW few groups to present and the rest to add points not mentioned |

| |

|CLARIFY and SUMMARIZE by using the contents below |

• The following is the answer for the above exercise:

The amount of drug will be calculated as

5000mg = 100mg
Xmg = 240mg
Xmg = 5000mg x 240mg/100mg
X = 12,000mg, answer

STEP 4: Key Points (5 minutes)

• The term milligrams percent w/v (mg %w/v) expresses the number of

milligrams of a substance in 100mL of a liquid

• It is used to frequently to donate the concentration of a drug or natural

substances in a biological fluid, as in the blood

STEP 5: Evaluation (10 minutes)

• What is the meaning of mg%w/v?
• What do you understand by 400mg%w/v dextrose solution?

References

Ansel, H. C & Stocklosa, M. J. (2001). Pharmaceutical Calculations (11th

ed.). Philadelphia, United States: LIPPINCOTT WILLIAMS & WILKINS

Ansel, H. C (2010) Pharmaceutical Calculations (13rd ed.). Philadelphia,

United States: LIPPINCOTT WILLIAMS & WILKINS

Senya, S. S, Mwasha, C.Y, Muyinga, A. M, Amiri,R. I. and Mauga E.A.S.K.

(2011) Tanzania Pharmaceutical Handbook (2nd ed.). Dar eS Salaam,

Tanzania: School of Pharmaceutical Sciences.

Zatz, J.L and Teixeira, M.G. (2005). Pharmaceutical Calculation (4th ed.).

New Jersey: John Wiley & Sons, Inc

PDF / OFFLINE NOTES

Unataka kutumiwa notes hizi kupitia WhatsApp?Kwa notes zilizopangiliwa vizuri kwa kusoma offline au PDF, bonyeza kitufe hapa chini. Ujumbe wenye Level, Semester, Module na Topic utaandaliwa moja kwa moja.TUMIWA NOTES WHATSAPP

WhatsApp: 255620339260
banner
Scroll to Top