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Reducing & Enlarging Formulas Presented by: Hevar Yassin Poshya Nadhim Yar Abdulkhalq Sara Subhan Niga Ahmed Diya Qadir 2 “ Objectives: by the end of this presentation we will be able to: - perform calculations to reduce or enlarge formulas for pharmaceutical preparations stated in metric quanti...

Reducing & Enlarging Formulas Presented by: Hevar Yassin Poshya Nadhim Yar Abdulkhalq Sara Subhan Niga Ahmed Diya Qadir 2 “ Objectives: by the end of this presentation we will be able to: - perform calculations to reduce or enlarge formulas for pharmaceutical preparations stated in metric quantities & proportional parts. Purpose of enlarging and reducing formulas  To calculate the quantities of each ingredient of a prescription that is required for a smaller or greater quantity by reducing or enlarging the specified formula, while maintaining the correct proportion of one ingredient to the other. 3 Important to Note  The quantitative relationship between ingredients is fixed; That is irrespective to the total quantity of formula prepared, the relative amount of one ingredient to another remains the same.  Formulas may be reduced or enlarged through the use of a factor.  The quantity of each ingredient in a formula is multiplied by a factor; To determine the quantity needed in a reduced or enlarged formula 4 Step-wise approach Step 1 :  Using the following equation, determine the factor that defines the multiple or the decimal fraction of the amount of formula prepared: o Quantity of formula desired/ Quantity of formula given = Factor 5  A factor greater than 1 represents the multiple of the formula.  A factor less than 1 indicates the fraction of the formula to be prepared. Step-wise approach Step 2:  Multiply the quantity of each ingredient in the formula by the factor to determine the amount of each ingredient in the reduced or enlarged formula. 6 Example: If a formula for 1000mL contains 6g of a drug, how many grams of drug are needed to prepare 60mL of the formula?  Step 1: calculate the factor o 60mL/1000mL = 0.06 (factor)  Step 2: using the factor, calculate the quantity for the ingredient o 6g *0.06 = 0.36 g So, 0.36g of drug is needed to prepare 60ml of the formula. 7 Application to Prescription From the following formula, calculate the quantity of each ingredient required to make 240ml of calamine o Calamine 80 g lotion: o Zinc Oxide 80 g o Glycerin 20 g o Bentonite Magma 250mL o Calcium Hydroxide Topical Solution, to make 1000mL. 8 Step 1: Calculate the factor: 240ml / 1000ml = 0.24 Application to Prescription Step 2: o Calculate the quantity of each ingredient:  Calamine = 80 g * 0.24 = 19.2 g  Zinc Oxide = 80 g * 0.24 = 19.2 g  Glycerin = 20 g * 0.24 = 4.8 mL  Bentonite Magma = 259 g * 0.24 = 60mL  Calcium Hydroxide Topical Solution, to make 240 mL 9 Example Calculate the quantity of each ingredient required to prepare a dozen 30mL containers using the following formula for artificial tears. o Polyvinyl Alcohol : 1.4 g o Povidone : 0.6 g o Chlorobutanol : 0.5 g o Sterile Sodium chloride Sol’u, 0.9% ad 100 ml Solution: 1. Total qty to make (mL). 30 *12 = 360 mL 2. Calculate the factor. 360/100 = 3.6 3. Using the factor, calculate the quantity for each ingredient 10 Cont. Rx o Polyvinyl Alcohol 5.04 g 1.4g * 3.6 = o Povidone 2.16 g 0.6g * 3.6 = o Chlorobutanol g 0.5g * 3.6 = 1.8 o Sterile Sodium Chloride Solution, 9% ad 360 mL 11 Proportional Parts The parts indicate the relative proportion of each of the ingredients in the formula by either weight or volume, but not both  A formula for solid or semisolid ingredients: • Considered in terms of grams.  A formula of liquid ingredients: • Considered in terms of milliliters. 12 Example: Calculation of a formula expressed in Parts From the following formula, calculate the quantity of each ingredient required to make 1000 g of the Ointment: o Coal Tar 5 parts o Zinc Oxide 10 parts o Hydrophilic Ointment 50 parts Note: the sum of the weight in grams will add up to the total weight of the ointment 13 Cont. Step 1: Calculate the total number of parts o Total number of parts by weight: 65 Step 3: Set up proportion for each ingredient and solve by weight parts Step 2: State total (g) will contain total parts o Coal tar: 65 p/1000g = 5p/(x) g o 1000g will contain 65 parts o Zinc Oxide: 65 p/1000g = 10p/ = 76.9g (y)g = 153.8g o Hydrophilic Oint.: 65p/1000g = 50p/ (z)g = 769.2 g 14 Advantages of Reducing Formulas  In pharmacy, reducing formulas are valuable for preparing smaller doses of medication.  It’s important for creating customized dosage for patients with specific needs or for preparing pediatric or lowerdose medications.  allowing pharmacists to accurately scale down medication quantities while maintaining their effectiveness. 15  They ensure precise measurements and proportions. Advantages of Enlarging Formulas  Enlarging formulas ensure a consistent and reliable supply for medication.  This allows patients to access their prescribed medications without interruption.  This ensures patients receive their required dosage especially for those needing long-term or recurring prescriptions 16 Disadvantages of Reducing and Enlarging Formulas • Calculations Calculating the quantities of ingredients to be used when reducing or enlarging a formula can be more complex than simply adjusting the quantity. • Precision When reducing or enlarging a formula, it is essential to be precise in the calculations to ensure the correct quantities of ingredients are used. • Concentration changes In some cases, reducing or enlarging a formula may result in a change in the concentration of the active ingredient. This can lead to variations in the product’s effectiveness and potency. 17 Dilution and concentration In contrast to reducing • and enlarging formulas, dilution and concentration questions involve changing the actual concentration or strength of the product. 18 “ To overcome these disadvantages, it’s crucial to understand the formula and the specific requirements of the desired product. additionally, using a calculator or software can help in precise calculations and ensuring the correct quantities of ingredients are used. “ Thanks for your attention!