Pharmaceutical Sciences Notes

NTA Level 4 • Semester 1 • PST04105 Calculations of Dilution and Concentration of Liquids Pharmaceutical Calculations • Source Session/Topic 9 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 9: Calculations of Dilution and Concentration of Liquids Total Session Time: 120 minutes Prerequisites None Learning Tasks By the end of this session students are expected to be able to: • Define dilution and concentration of liquids • Calculating dilution and concentration of liquids 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 |30 minutes |Presentation |Definition of Dilution and | | | | |concentration of Liquids | |3 |50 minutes |Presentation | Dilution and Concentration of | | | |Group |Liquids | | | |discussion | | |4 |10 minutes |Presentation |Key Points | | 5 |25 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: Definition of Dilution and Concentration of Liquids (30 Minutes) Dilution If a mixture of a given percentage or ratio strength is diluted to twice its original quantity, its active ingredient will be contained in twice as many parts of the whole, and its strength therefore will be reduced by one half For example: if 50 mL of a solution containing 10 g of active ingredient with a strength of 20% or 1:5 w/v are diluted to 100 mL, the original volume is doubled, but the original strength is now reduced by one half to 10% or 1:10 w/v Concentration By contrast, if a mixture is concentrated by evaporation to one-half its original quantity, the active ingredient (assuming that none was lost by evaporation) will be contained in one half as many parts of the whole, and the strength will be doubled For example: : if 50 mL of a solution containing 10 g of active ingredient with a strength of 20% or 1:5 w/v is reduced by evaporation to 25 mL or one half the original quantity, the 10 g of the active ingredient will indicate a strength of 40% or 1:2.5 w/v Therefore, the amount of active ingredient remains constant, any change in the quantity of a solution or mixture of solids is inversely proportional to the percentage or ratio strength; that is, the percentage or ratio strength decreases as the quantity increases, and conversely This relationship is generally true for all mixtures except solutions containing components that contract when mixed together This type of calculation is very important in the pharmaceutical field, because most of the reagent/ chemicals used in the hospitals are received in a concentrated form, and they will have to be diluted to desired strength before use Dilution of Liquids is done generally may be solved by the following equation: (1st Volume) x (1st Concentration)_= (2nd Volume) x (2nd Concentration), or V1 X C1 = V2 X C2. Wheres V1 = Volume of strong solution C1 = concentration of strong solution V2 = Volume of diluted solution C2 = concentration of diluted solution STEP 3: Dilution and Concentration of Liquids (50 Minutes) |Activity: Small Group Discussion ( 20 minutes) | | | |DIVIDE students into small manageable groups | | | |ASK students to discuss on the following question | |Exercise 1: Calculate the volume of alcohol 90% v/v needed to prepare | |400 mL of alcohol 70% v/v | |Exercise 2: How many mL of formalin 2% v/v will be prepared from 350 mL| |of formalin 36% v/v | |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 are the solutions of the above exercises: Exercise 1: Information given; Concentration of strong solution (C1) = 90% Volume of the strong solution (V1) = X? Concentration of weak solution (C2) = 70% Volume of the weak solution (V2) = 400 mL Formula C1V1= C2V2 V1= C2V2 C1 X = (70%×400 mL)/90% = 311.11 mL of 90% alcohol will be needed to prepare 400 mL of 70% alcohol. Exercise 2: Information given; Concentration of strong solution (C1) = 36% Volume of the strong solution (V1) = 350 mL Concentration of weak solution (C2) = 2% Volume of the weak solution (V2) = X mL Formula C1V1= C2V2 V2= C1V1 C2 V2=( 36%×350 mL)/2 =6300 mL of 2% formalin solution will be prepared from 350 mL of 36% formalin. STEP 4: Key Points (10 minutes) • Calculating dilution by using ratio; C1V1=C2V2 • This is the method of calculating dilution of a drug by using the concentration of strong drug and concentration of diluted drug and their volume. • This type of calculation is very important in the pharmaceutical field as most of pharmaceutical solutions needed to be diluted prior for use • Dilution reduces the concentration of a solution STEP 7: Evaluation (25 minutes) • What is dilution of liquid? • What is concentration of liquid? • What is the volume of potassium permanganate 10%w/v needed to prepare 2000 mL of 1%w/v solution of potassium permanganate? • What volume of dextrose 5% w/v solution will be prepared from 500 mL of dextrose 25%w/v 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).

NTA Level 4 • Semester 1 • PST04105 Calculations of Quantities of Water to Use for Reconstituting Pharmaceutical Calculations • Source Session/Topic 10 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 10: Calculations of Quantities of Water to Use for Reconstituting Powders for Oral and Parental Preparations Total Session Time: 120 minutes Prerequisites • None Learning Tasks By the end of this session students are expected to be able to: • Calculate the Volume of Dry Powder and Quantity of Drug Present • Calculating the amount of water to be used for reconstitution of oral and parenteral preparations 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 |40 minutes |Presentation |Calculate the Volume of Dry Powder | | | |Group |and Quantity of Drug Present | | | |discussion | | |3 |40 minutes |Presentation |Calculate the Amount of Water to be | | | |Group |Used For Reconstitution of Oral and | | | |discussion |Parenteral Preparations | |4 |10 minutes |Presentation |Key Points | | 5 |25 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: Calculate the Volume of Dry Powder, Total Drug Present (40 minutes) • Some drugs lose their potency in a relatively short period of time when prepared in a liquid dosage form, o Thus to enhance its shelf life, manufacturers provide products to the pharmacy in dry powder form for constitution with purified water or special diluents at the time a prescription or medication order is received • After constitution, the resultant solution or suspension is stable in the quantities usually dispensed, for up to 10 days at room temperature or 14 days if maintained under refrigeration • For children and adult, constituted products for oral solution or suspension generally are formulated such that the usual dose of the drug is contained in teaspoonful amounts of product • Calculating the amount of water to be used for reconstitution of oral and parenteral preparations o This calculation involved in calculating the amount of diluents required to reconstitute the powder for oral solution or injectable in order to get the desired concentration o Dry powder for constitution are packed in self-contained bottles of sufficient size to accommodate the additional of the required volume of diluents o In additional to the quantitative amount of therapeutic agent, the powder contains such pharmaceutical ingredients as solubilizing agents, stabilizers, colorants, sweeteners, and flavorants |Activity: Small Group Discussion ( 20 minutes) | | | |DIVIDE students into small manageable groups | | | |ASK students to discuss on the following question | |The label instructions for an ampicillin product call for addition of | |78 mL of water to make 100 mL of constituted suspension such that each | |5mL contains 125 mg of Ampicillin. What is the volume occupied by dry | |powder and the total drug present? | | | |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: Volume of dry powder Because the additions of 78 mL of water result in the preparation of 100 mL of product, the volume occupied by dry powder is: 100 mL-78 mL= 22 mL 22 mL is the volume occupied by dry powder. Total drug (ampicillin) present If in the constituted product, each 5 mL contains 125 mg of ampicillin, the total amount of ampicillin in the 100 mL product is: If 5 mL contains 125 mg of ampicillin 100 mL will contain how many mg of ampicillin? (100 mL × 125 mg)/ 5 mL =2500 mg of ampicillin is in the drug product. STEP 3: To Calculate the Amount of Water to be Used for Reconstitution of Oral and Parenteral Preparations (40 minutes) |Activity: Small Group Discussion ( 20 minutes) | | | |DIVIDE students into small manageable groups | | | |ASK students to discuss on the following question | |The label instructions for an ampicillin product call for addition of | |78 mL of water to make 100 mL of constituted suspension such that each | |5mL contains 125 mg of Ampicillin. If the physician desires an | |ampicillin concentration of 100 mg/5 mL (rather than 125 mg/5 mL), how | |many milliliter of water should be added to the dry powder? | | | |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 are the answers of the above exercise: Because it was determined that 2500 mg (from step number 2 above) of ampicillin are in the dry product, the volume of product that can be made with a concentration of 100 mg/5 mL may be calculated by, If in every 5 mL of suspension contains 100 mg of ampicillin, Then X mL of suspension contains 2500 mg of ampicillin. X mL= (5 mL ×2500 mg)/ 100 mg X mL= 125 mL of the drug product (ampicillin suspension) Then, because it had been determined that the dry powder occupies 22 mL of volume, it is possible to determine the amount of water to add: 125 mL-22 mL=103 mL Answer STEP 4: Key Points (10 minutes) • A number of drugs are unstable in an aqueous environment, even when exposed for a short duration, thus requiring packaging, storage, and shipping in a powder or lyophilized

NTA Level 4 • Semester 1 • PST04105 Calculations of Doses for Paediatrics and Geriatrics Based on Pharmaceutical Calculations • Source Session/Topic 11 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 11: Calculations of Doses for Paediatrics and Geriatrics Based on Age, Body Weight and Body Surface Area Total Session Time: 120 minutes Prerequisites • None Learning Tasks By the end of this session students are expected to be able to: • Calculating the dose for paediatric by using age of a child • Calculating the dose for paediatric by using body weight of a child • Calculating the dose for paediatric by using body surface area • Calculating of doses for elderly (geriatric) patients 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 |30 minutes |Presentation |Calculation of Paediatric Dose by | | | |Group |Using Age of a Child | | | |discussion | | |3 |30 minutes |Presentation |Calculation of Paediatric Dose by | | | |Group |Using Body Weight of a Child | | | |discussion | | |4 |30 minutes |Presentation |Calculation of Paediatric Dose by | | | |Group |Using Body Surface Area | | | |discussion | | |5 |10 minutes |Presentation |Calculations of Doses For Elderly | | | | |(Geriatric) Patients | |6 |05 minutes |Presentation |Key Points | |7 |05 minutes |Presentation |Evaluation | |8 |05 minutes |Presentation |Take Home Assignment | 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: Calculation of Paediatric Dose by Using Age of a Child (30 minutes) • When paediatric doses for a medication are not given, they can be calculated from the adult dose, taking into account body-surface area, body-weight or age. • Usually children are divided into four age groups; o Neonates: 1 to 28 days o Infants: 4 weeks to one year o Children: 1 to 5 years o Children: 6 to 12 years • The age of the individual being treated is frequently a consideration in the determination of the drug dosage, especially in the young and very old • The rationale for dose adjustment in paediatric indications may be determined by differences in pharmacokinetics, pharmacodynamics, disease or a combination of these factors • Pharmacokinetics of drugs in children may differ from adults for several reasons such as: o age o gender o body composition o functionality of liver and kidneys o maturation of enzymatic systems throughout the life span from neonates to adults • There are different formulas for determination of paedriatic (child) dose based on age, these include: o Young’s Rule; Age (in years)/(Age + 12) × Adult dose = Dose for Child o Fried’s Rule; (Age ( in months) × Adult dose)/150 = Dose for Child |Activity: Small Group Discussion ( 15 minutes) | | | |DIVIDE students into small manageable groups | | | |ASK students to discuss on the following question | |Calculate the dose for 6-years old child when the adult dose is 600 mg | |What is the dose of a medication for a twelve months old child when the| |adult dose is 100 mg? | | | |ALLOW students to discuss for 10 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: • Child’s dose = 6/(6+12) × 600 =200 mg The child’s dose is 200 mg Answer • Child’s dose = (12 × 100)/150 = 8 mg The child’s dose is 8 mg Answer STEP 3: Calculation of Paediatric Dose by Using Body Weight of a Child (30 minutes) • The usual doses for drugs are considered generally suitable for 70kg (154- lb) individuals • The determination of drug dosage for young patient on the bases of body weight is considered more dependable than that based strictly on age • The dosage of a number of drug substances is based on body weight and is frequently expressed on a milligram (drug) per kilogram (body weight) or milligram per pound bases • Formulas for calculating child’s dose based on body weight include: o Child’s dose = (child body weight (Kg) × Adult dose)/70 Kg o Child’s dose = (child body weight (lb) × Adult dose)/150 lb |Activity: Small Group Discussion ( 15 minutes) | | | |DIVIDE students into small manageable groups | | | |ASK students to discuss on the following question | |Calculate the dose for a child which weighs 17.5 Kg when the adult dose| |is 0.5 g | |If the adult dose of a drug is 75mg, what will be the dose for a child | |weighing 40 lb? | |ALLOW students to discuss for 10 minutes | | | |ALLOW few groups to present and the rest to add points not mentioned | | | |CLARIFY and SUMMARIZE by using the contents below | • The following are the answers of the above exercise Child’s dose = (17.5Kg × 0.5 g)/70 Kg = 0.125 g The child’s dose is 0.125g answer Child’s dose = (40 lb × 75 mg)/150 lb = 20 mg The child’s dose is 20 mg answer STEP 4: Calculation of PaediatricDose by Using Body Surface Area and Height ( 30 minutes) • Dose calculated on bases of body surface area (BSA) or body weight is much more satisfactory and always needed when the margin between therapeutic and toxic dose is narrow • For more precise calculation of doses based on BSA, one should refer to a standard nomograph, which

NTA Level 4 • Semester 1 • PST04105 Calculations of Dosage of Heparin Pharmaceutical Calculations • Source Session/Topic 12 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 12: Calculations of Dosage of Heparin Total Session Time: 60 minutes Prerequisites • None Learning Tasks By the end of this session students are expected to be able to: • Calculating dosage of heparin 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 |15 minutes |Presentation |Definition of Heparin | | | |Group | | | | |discussion | | |3 |30 minutes |Presentation |Calculation of Heparin dosage | | | |Group | | | | |discussion | | |4 |5 minutes |Presentation |Key points | | 5 |5 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: Definition of Heparin (15 minutes) |Activity: Brainstorming (5 minutes) | | | |Ask students to brainstorm on the following question: | | | |What is a Heparin? | | | |ALLOW few students to respond | | | |WRITE their responses on the flip chart/ board | | | |CLARIFY and SUMMARISE by using the content below | • Heparin is a drug that has anticoagulant properties. • Heparin slows clotting time and is therefore used as anticoagulant • There are two types of Heparin preparations: o Unfractioned Heparin o Low Molecular weight heparins • Heparin salts are administered as sterile aqueous solutions by intravenous infusion, intermittent intravenous injection, or deep subcutaneous injection. STEP 3: Calculation of Unfractioned Heparin Dosing (30 minutes). |Activity: Small Group Discussion ( 20 minutes) | | | |DIVIDE students into small manageable groups | | | |ASK students to discuss on the following question | |An intravenous infusion contained 20,000 units of heparin sodium in | |1000 mL of D5W. The rate of infusion was set at 1600 units per hour for| |a 160-lb. patient. | |Calculate: | |(a) The concentration of heparin sodium in the infusion, in units/mL; | |(b) The length of time the infusion would run, in hours; | |(c) The dose of heparin sodium administered to the patient, on a | |unit/kg/minute basis. | | | |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 are the answers of the above exercise: a) 20000 units/1000mL = 20 units/mL b) 20000 units/20 units/mL = 12.5hrs c) 160pounds = 72.7kg 12.5 hrs = 750 minutes 20000 units/750 minutes = 26.67 unit/minute 26.67 unit/minute / 72.7 kg = 0.37 units/kg/min Answers STEP 4: Key Points (5 minutes) • Heparin is used as anticoagulant; however, its use carries with it, the risk of hemorrhage • Bolus doses, given by direct intravenous injection, may be followed by intravenous infusion as a heparin drip • Low-dose heparin administration provides effective prophylaxis (rather than therapeutic effects) in a variety of surgical procedures STEP 5: Evaluation (5 minutes) • What is Heparin? • How do you calculate the dose of Heparin? 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 ← Previous TopicNext Topic →View all Pharmaceutical Calculations topicsOpen Complete Full Notes 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

NTA Level 4 • Semester 1 • PST04105 Calculations of Percentage Strength of Weight-In-Volume (%W/V) Pharmaceutical Calculations • Source Session/Topic 13 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 13: Calculations of Percentage Strength of Weight-In-Volume (%W/V) Total Session Time: 120 minutes Prerequisites • None Learning Tasks By the end of this session students are expected to be able to: • Define the percentage %W/V of a given product • Calculate the amount of a product/active ingredient from a given percentage %W/V 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 |25 minutes |Presentation |Definition of Percentage %W/V of a | | | |Brainstorming |Given Product | |3 |60 minutes |Presentation |Calculation of the Amount of a | | | |Group |Product/Active Ingredient From a | | | |discussion |Given Percentage %W/V | |4 |15 minutes |Presentation |Key Points | | 5 |15 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: Percentage %W/V of a Given Product (25 minutes ) |Activity: Brainstorming (5 minutes) | | | |Ask students to brainstorm on the following question: | | | |What is percentage weight in volume? | | | |ALLOW few students to respond | | | |WRITE their responses on the flip chart/ board | | | |CLARIFY and SUMMARISE by using the content below | • Percentage weight-in-volume indicates the number of parts by weight (gm) of active ingredient contained in the total volume of the solution or mixture considered as 100 parts by volume • Weight of active ingredient in a specific volume of a solution, given its weight-in-volume percentage strength. o i.e. volume (mL)(represent gram)×%(expressed as a decimal)= gm of active ingredient • Example: 5 %( w/v) dextrose solution o This means that 5 gm of active ingredient (dextrose powder) in every 100 mL of the dextrose solution (i.e. 5 gm dextrose powder are in 100 mL of dextrose solution or 5 gm of dextrose powder plus enough water to make 100 mL solution) STEP 3: The Amount of a Product/Active Ingredient From a Given Percentage %W/V (60 minutes) |Activity: Small Group Discussion ( 20 minutes) | | | |DIVIDE students into small manageable groups | | | |ASK students to discuss on the following question | |What is the percentage strength (w/v) of a solution of urea, if 80 mL | |contains 12 gm? | |How many gram of dextrose will be needed to prepare 200 mL of 5%w/v | |dextrose 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 are the answers of the above exercise: 80 mL of water weigh 80 gm 80 gm/ 12 gm= 100%/X% X = (12 × 100) / 80 = 15%, answer Weight of dextrose will be calculated as; 100%/5% = 200 mL/X mL X= (200 × 5) / 100 = 10 gm, answer STEP 4: Key Points (15 minutes) • Percentage weight in volume represents the number in grams of active ingredient/substance in 100 mL of the drug product STEP 5: Evaluation (15 minutes) • What is the meaning of percentage weight-in-volume? • What do you understand by the term sodium chloride 0.9%w/v (normal saline)? 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 ← Previous TopicNext Topic →View all Pharmaceutical Calculations topicsOpen Complete Full Notes 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

NTA Level 4 • Semester 1 • PST04105 Calculations of Percentage Strength Volume-In-Volume (%V/V) Pharmaceutical Calculations • Source Session/Topic 14 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 14: Calculations of Percentage Strength Volume-In-Volume (%V/V) Total Session Time: 120 minutes Prerequisites • None Learning Tasks By the end of this session students are expected to be able to: • Define the percentage %V/V of a given product • Calculate the amount of a product/active ingredient from a given percentage %V/V. 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 |25 minutes |Presentation |Definition of Percentage %V/V of a | | | | |Given Product | |3 |65 minutes |Presentation |Calculations of The amount of a | | | |Group |Product/Active Ingredient From a | | | |discussion |Given Percentage %V/V | |4 |10 minutes |Presentation |Key Points | | 5 |15 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: Percentage %V/V of a Given Product (25 minutes) |Activity: Buzzing (10 minutes) | | | |ASK students to pair up and buzz on the following question for 5 | |minutes | | | |What is percentage %V/V of a given product? | | | |ALLOW few pairs to respond and let other pairs to add on points not | |mentioned | | | |WRITE their response on the flip chart/board | | | |CLARIFY and SUMMARIZE by using the content below | • Percentage volume-in-volume indicates the number of parts by volume (mL) of active ingredient contained in the total volume of the solution or mixture considered as 100 parts by volume • For example: 70 %( v/v) alcohol means that 70 mL of active ingredient (absolute alcohol) in 100 mL of the alcohol solution. • A 0.5%v/v solution of chloroform in water contains 0.5 mL of chloroform in 100 mL solution (i.e. 0.5 mL chloroform plus 99.5 mL water) STEP 3: The Amount of a Product/Active Ingredient from a Given Percentage %V/V (65 minutes) • Volume of active ingredient in a specific volume of a solution, given its volume-in-volume percentage strength. • i.e. volume (mL) × %(expressed as a decimal)= mL of active ingredient • This will involve the following; Example: • How many milliliters of liquefied phenol should be used in compounding the following prescription? Rx Liquefied phenol……………………2.5% Calamine lotion………….…ad 240.0 mL Sig. For external use Solution: Volume (mL) × %( expressed as a decimal) = mL of active ingredient 240 mL× 0.025 = 6 mL, answer |Activity: Small Group Discussion ( 20 minutes) | | | |DIVIDE students into small manageable groups | | | |ASK students to discuss on the following question: | |In preparing 250 mL of a certain solution, a pharmacist used 4 mL of | |Liquefied phenol. What was the percentage (v/v) of Liquefied phenol in | |the lotion? | | | |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 %( expressed as a decimal) = mL of active ingredient/ volume (mL) 4 mL/250 mL =0.016 × 100 mL (to get percentage) =1.6% v/v, answer STEP 4: Key Points (10 minutes) • Percentage volume in volume represents the number in millilitres of active ingredient/substance in 100 mL of the drug product STEP 5: Evaluation (15 minutes) • What is the meaning of percentage volume-in-volume? • What do you understand by the term sodium chloride 0.5%v/v chloroform 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 ← Previous TopicNext Topic →View all Pharmaceutical Calculations topicsOpen Complete Full Notes 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

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 ← Previous TopicNext Topic →View all Pharmaceutical Calculations topicsOpen Complete Full Notes 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

NTA Level 4 • Semester 1 • PST04105 Calculations of Ratio Strength (%W/W, %W/V, %V/V, Ppm) Pharmaceutical Calculations • Source Session/Topic 16 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 16: Calculations of Ratio Strength (%W/W, %W/V, %V/V, Ppm) Total Session Time: 120 minutes + 1 hours Assignment Prerequisites None Learning Tasks By the end of this session students are expected to be able to: • Calculating the ratio strength of a product from given %W/W , %W/V , %V/V and ppm 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 |60 minutes |Presentation |Ratio Strength of a Product From | | | |Group |Given %W/W, %W/V, %V/V. | | | |discussion | | |3 |20 minutes |Presentation |Parts Per Million (Ppm) | | | |Group | | | | |discussion | | |4 |10 minutes |Presentation |Key Points | |5 |15 minutes |Presentation |Evaluation | |6 |10 minutes |Presentation |Take Home Assignment | 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: Ratio Strength of a Product From Given %W/V, %V/V, and %W/W (60 minutes), • The concentration of weak solutions or liquid preparations is frequently expressed in terms of ratio strength • Because all percentages are ratio of parts per hundred, ratio strength is merely another way of expressing the percentage strength of solutions or liquid preparations (and less frequently, of mixtures of solids) o For example: 5% means 5 parts per 100 or 5:100, although 5 parts per 100 designates ratio strength; it is customary to translate this designation into a ratio; thus 5:100 = 1:20 • When a ratio strength for example 1:1000, is used to designate a concentration, it is to be interpreted as follows: o For solids in liquids = 1 gm of solute or constituents in 1000 mL of solution or liquid preparation o For liquids in liquids = 1 mL of constituents in 1000 mL of solution or liquid preparation o For solids in solids = 1 gm of constituents in 1000 gm of mixture |Activity: Small Group Discussion ( 20 minutes) | | | |DIVIDE students into small manageable groups | | | |ASK students to discuss on the following question | |Express 0.02% as a ratio strength | |Express 1;4000 as a percentage strength | |A certain injectable contains 2 mg of a drug per milliliter of | |solution, what is the ratio strength (w/v) of the 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 answers for the above exercise: 0.02 parts per 100 1 part per X X = 1 part x 100/0.02 X (parts) = 5000 The ratio strength = 1:5000, answer. 4000(parts)/1(part) = 100 (%)/X (%) X = 0.025%, answer 2 mg = 0.002 gm 0.002 (gm)/1 (gm) = 1 (mL)/X (mL) X = 500 mL Ratio strength = 1:500, answer STEP 3: Parts per Million (ppm) (20 Minutes) • The strength of very dilute solutions is commonly expressed in terms of parts per million (ppm); that is the number of parts of the agent per one million parts of the whole. • For example, fluorinated drinking water, used to reduce dental carries, often contains 1 part of fluoride per million parts of drinking water (1:1,000,000). • The ppm concentration of a substance may be expressed in quantitatively equivalent values of percentage strength or ratio strength. Example: o Express 5 ppm of iron in water in percentage strength and ratio strength. o Solution: 5 ppm = 5 parts in 1,000,000 parts = 1:200,000, ratio strength, answer = 0.0005%, percentage strength answer. |Activity: Small Group Discussion ( 15 minutes) | | | |DIVIDE students into small manageable groups | | | |ASK students to discuss on the following question | |The concentration of the drug additive in an animal feed is 12.5 ppm. | |How many mgs of drugs should be used in preparing 5.2 kg of feed? | | | |ALLOW students to discuss for 10 minutes | | | |ALLOW few groups to present and the rest to add points not mentioned | | | |CLARIFY and SUMMARIZE by using the contents below | • The following are the answers of the above exercise. 12.5 ppm = 12.5 gm (drug) in 1,000,000 gm (feed) Thus, 1,000,000 gm / 12.5 gm = 5200 gm / X gm X = 0.065 gm = 65 mg, answer STEP 4: Key Points (10 minutes) • The concentration of weak solutions or liquid preparations is frequently expressed in terms of ratio strength. • The ratio and percentage strengths of any solution or mixture of solids are proportion, and either is easily converted to the others by the use of proportion. • The strength of very dilute solutions is commonly expressed in terms of parts per million (ppm) STEP 5: Evaluation (15 minutes) • What do you understand by the following : percentage strength w/w, %w/v, %v/v, ratio strength and parts per million. STEP 6: Take Home Assignment (10 minutes) |Activity: Take home Assignment (10 minutes) | | | |ASK each individual student to do the following assignment | | | | | |Express 1:200 as percentage strength. | |Express 0.05% as ratio strength. | |Express 100ppm as ratio strength. | |Express 0.005% as percentage strength | | | |ALLOCATE time for students to do the assignment and submit | | | |REFER students to recommended references | References Ansel, H.

NTA Level 4 • Semester 1 • PST04105 Calculations of Quantities of Each Ingredient Required for Compounding Pharmaceutical Calculations • Source Session/Topic 17 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 17: Calculations of Quantities of Each Ingredient Required for Compounding Total Session Time: 120 minutes + 1 hours Assignment Prerequisites • None Learning Tasks By the end of this session students are expected to be able to: • Calculate the amount of drug required for compounding from a given prescription • Calculate the ratio (factor) of quantity needed for compounding • Enlarge or reduce formula by using the factor • Determine dilutions of reduced and enlarged formula 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 |20 minutes |Presentation |Amount of Drug Required For | | | | |Compounding From a Given | | | | |Prescription | |3 |30 minutes |Presentation |Ratio (Factor)of Quantity Needed For| | | |Small Group |Compounding | | | |discussion | | |4 |20 minutes |Presentation |Enlarging or Reducing of Formula by | | | | |Using the Factor | |5 |30 minutes |Presentation |Dilution of Reduced and Enlarged | | | | |Formula | |6 |05 minutes |Presentation |Key Points | | 7 |05 minutes |Presentation |Evaluation | | 8 |05 minutes |Presentation |Take Home Assignment | 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: Calculating Amount of Drug Required for Compounding From a Given Prescription (20 minutes) When the amount of prescribed or ordered medicines deviates from the official quantities of a formula in a reference book the amount of each ingredient for compounding can be obtained or calculated Example: Dispense: Paracetamol syrup 250 mg tds 3/7, Available Paracetamol syrup 125 mg Paracetamol per 5 mL Solution; 250 mg (Paracetamol) × 3 × 3 = 2250 mg of Paracetamol. 5 mL of Paracetamol syrup contains 125 mg of Paracetamol X mL of Paracetamol syrup will contains 2250 mg of Paracetamol. (5 mL× 2250) / 125 = 90 mL of Paracetamol syrup to be dispensed, Answer STEP 3: Calculating Ratio of Quantity Needed for Compounding (30 minutes) In order to reduce or enlarge the formula the following ratio / factor are the mostly used; Factor = Total amount required / total amount of the official formula Example of reducing formula: Codeine phosphate syrup PCx: Codeine phosphate———————————-5 gm Purified water freshly boiled and cooled———15 mL Chloroform spirit————————————25 mL Syrup———————————————to 1000 mL Sig; 5mL q.i.d 4/7 Solution: Prescribed amount is: 5 × 4 × 4 = 80 mL Factor = 80 mL/ 1000 mL = 0.08 |Activity: Small Group Discussion ( 20 minutes) | | | |DIVIDE students into small manageable groups | | | |ASK students to discuss on the following question: | | | |Ammonium chloride mixture PCx | |Ammonium chloride ——————————–10 gm | |Aromatic ammonia solution————————5 mL | |Liquorice liquid extract—————————–10 mL | |Water for preparations————————–to 100mL | |Sig; ammonium chloride mixture 10 mL tds 5/7 | | | |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 are the answers of the above exercise: The amount of drug to be dispensed will be calculated as; 10 mL × 3 × 5 = 150 mL to be dispensed Factor = Total amount required / total amount of the official formula = 150 mL/ 100 mL = 1.5, answer STEP 4: Enlarging or Reducing of Formula by Using the Factor (20 minutes) • Pharmaceutical personnel may have to reduce or enlarge formulas for pharmaceutical preparations in the course of their practice • Official formulas and most other formulas for manufacturing are based on the preparation of 1000 mL or 1000 gm of product The pharmaceutical personnel may be called on to make a smaller or greater quantity and thus must reduce or enlarge the formula while maintain the correct proportion of each ingredient Examples: • Reducing of the formula Codeine phosphate syrup PCx Official amount |Codeine phosphate |5 gm | |Purified water freshly boiled and cooled |15 mL | |Chloroform spirit |25 mL | |Syrup |to 1000 mL | Sig; 5mL q.i.d 4/7 Solution; Prescribed amount is: 5 × 4 × 4 = 80 mL Factor = 80 mL/ 1000 mL = 0.08 Hence the formula will be as follows Codeine phosphate syrupPCx | |Official amount |Factor |Required | | | | |amount | |Codeine phosphate |5 gm |0.08 |0.4 gm | |Purified water freshly boiled|15 mL |0.08 |1.2 mL | |and cooled | | | | |Chloroform spirit |25 mL |0.08 |2.0 mL | |Syrup |to 1000 mL |0.08 |to 80 mL | • Enlarging of formula Ammonium chloride mixture PCx | |Official amount | |Ammonium chloride |10 gm | |Aromatic ammonia solution |5 mL | |Liquorice liquid extract |10 mL | |Water for preparations |to 100mL | Sig; ammonium chloride mixture 10 mL tds 5/7 The following are the answers of the above exercise The amount of drug to be dispensed will be calculated as; 10 mL × 3 × 5 = 150 mL to be dispensed Factor = Total amount required / total amount of the official formula = 150 mL/ 100 mL Factor = 1.5 Hence the formula will become; Ammonium chloride mixture PCx | |Official |Factor |Required amount | | |amount | | | |Ammonium chloride |10 gm |1.5 |15 gm | |Aromatic ammonia |5 mL |1.5 |7.5 mL | |solution | | | | |Liquorice liquid extract|10 mL |1.5 |15 mL |

NTA Level 4 • Semester 1 • PST04105 Calculations of Dilution and Concentration of Solids and Semisolids Pharmaceutical Calculations • Source Session/Topic 18 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 18: Calculations of Dilution and Concentration of Solids and Semisolids Total Session Time: 60 minutes Prerequisites None Learning Tasks By the end of this session students are expected to be able to: • Define dilution and concentration of Solids and Semisolids • Calculating dilution and concentration of Solids and Semisolids 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 |20 minutes |Presentation |Definition of Dilution and | | | | |concentration of Solids and | | | | |Semisolids | |3 |25 minutes |Presentation | Dilution and Concentration of | | | |Group |Solids and Semisolids | | | |discussion | | |4 |05 minutes |Presentation |Key Points | | 5 |05 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: Definition of Dilution and Concentration of Solids and Semisolids (20 Minutes) |Activity: Brainstorming (5 minutes) | | | |Ask students to brainstorm on the following question: | | | |What is dilution and concentration of solids and Semisolids? | | | |ALLOW few students to respond | | | |WRITE their responses on the flip chart/ board | | | |CLARIFY and SUMMARISE by using the content below | • The dilution of solids in pharmacy occurs when there is need to achieve a lower concentration of an active component in a more concentrated preparation (e.g., a powdered vegetable drug) • There is also a type of diluted pharmaceutical preparation, termed a trituration that represents a useful means of preparing and administering very potent therapeutic substances • Reducing or enhancing the strengths of creams and ointments is a usual part of a compounding Pharmaceutical personnel’s practice to meet the special needs of patients • The dilution of semisolids is a usual part of a compounding pharmaceutical personnel’s practice in reducing the strengths of creams and ointments to meet the special needs of patients STEP 3: Dilution and Concentration of Solids and Semisolids (25 Minutes) |Activity: Small Group Discussion ( 15 minutes) | | | |DIVIDE students into small manageable groups | | | |ASK students to discuss on the following question | |If 30 g of a 1% hydrocortisone ointment were diluted with 12 g of | |Vaseline, what would be the concentration of hydrocortisone in the | |mixture? | | | |How many grams of zinc oxide should be added to 3200 g of 5% zinc oxide| |ointment to prepare an ointment containing 20% of zinc oxide? | | | |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 are the solutions of the above exercises: 30 g x 1% = 0.3 g hydrocortisone 30 g x 12 g = 42 g, weight of mixture 0.3 g x 100 = 0.71% (w/w), answer. 42 g Or, 30 (g) x 1 (%) = 42 (g) x x(%) x = 0.71% (w/w), answer. (2) 3200 g x 0.05 = 160 g of zinc oxide in 3200 g of 5% ointment 3200 g x 160 g = 3040 g of base (diluent) in 3200 g of 5% ointment In the 20% ointment, the diluent will represent 80% of the total weight 80 (%) = 3040 (g) 20 (%) x (g) x = 760 g of zinc oxide in the 20% ointment Because the 5% ointment already contains 160 g of zinc oxide, 760 g – 160 g = 600 g, answer. STEP 4: Key Points (5 minutes) • The dilution of solid dosage forms such as powders or semisolids dosage forms such as ointments and creams may be performed to alter the dose or strength of the product • The concentration of solid and semisolids dosage forms also known as fortification, by addition of calculated quantity of additional therapeutic agent, remains a viable practice in pharmaceutical compounding STEP 7: Evaluation (15 minutes) • What is dilution of solids and semisolids? • What is concentration if solids and semisolids? • How many grams of 20% benzocaine ointment and how many grams of ointment base (diluent) should be used in preparing 5 lb. of 2.5% benzocaine ointment? 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 ← Previous TopicNext Topic →View all Pharmaceutical Calculations topicsOpen Complete Full Notes 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