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What is the purpose of a diluent in a pharmaceutical preparation?
What is the purpose of a diluent in a pharmaceutical preparation?
Which of the following is the correct definition of a stock solution?
Which of the following is the correct definition of a stock solution?
When diluting a 15% v/v solution of methyl salicylate to 1500 mL, what calculation method is appropriate?
When diluting a 15% v/v solution of methyl salicylate to 1500 mL, what calculation method is appropriate?
How can you strengthen a pharmaceutical preparation?
How can you strengthen a pharmaceutical preparation?
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What does 'alligation' refer to in problem-solving for pharmaceutical calculations?
What does 'alligation' refer to in problem-solving for pharmaceutical calculations?
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If 50 mL of a 1:20 w/v solution is diluted to 1000 mL, what type of strength calculation is performed?
If 50 mL of a 1:20 w/v solution is diluted to 1000 mL, what type of strength calculation is performed?
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To produce a 10% w/w ammonia solution from an available 28% w/w stock solution, what is a key step in problem-solving?
To produce a 10% w/w ammonia solution from an available 28% w/w stock solution, what is a key step in problem-solving?
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What is the outcome when diluting a stronger solution with a likened weaker preparation?
What is the outcome when diluting a stronger solution with a likened weaker preparation?
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What calculation result is expected when creating 4 L of a 1:2000 w/v solution using a 1:400 w/v stock?
What calculation result is expected when creating 4 L of a 1:2000 w/v solution using a 1:400 w/v stock?
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Which calculation method should you apply to determine how much of a concentrated solution is needed for dilution?
Which calculation method should you apply to determine how much of a concentrated solution is needed for dilution?
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How many milliliters of a 1% stock solution are needed to prepare 4000 mL of a mouthwash containing 1 : 20,000 w/v of red dye?
How many milliliters of a 1% stock solution are needed to prepare 4000 mL of a mouthwash containing 1 : 20,000 w/v of red dye?
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In a prescription with a 1 : 50 stock solution of ephedrine sulfate, how would you determine the volume required?
In a prescription with a 1 : 50 stock solution of ephedrine sulfate, how would you determine the volume required?
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What is the correct method to calculate the percentage strength of a mixture in alligation?
What is the correct method to calculate the percentage strength of a mixture in alligation?
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When mixing 200 g of a 10% ointment, 50 g of a 20% ointment, and 100 g of a 5% ointment, how do you find the final percentage of zinc oxide?
When mixing 200 g of a 10% ointment, 50 g of a 20% ointment, and 100 g of a 5% ointment, how do you find the final percentage of zinc oxide?
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How much should be added to a 300 mL solution of 1 : 750 w/v benzalkonium chloride to achieve a final concentration of 1 : 2500 w/v?
How much should be added to a 300 mL solution of 1 : 750 w/v benzalkonium chloride to achieve a final concentration of 1 : 2500 w/v?
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What is required to be considered when calculating dilutions involving solvents?
What is required to be considered when calculating dilutions involving solvents?
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What method can be used to determine the percentage v/v of alcohol in a mixed solution of different strengths?
What method can be used to determine the percentage v/v of alcohol in a mixed solution of different strengths?
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To prepare 30 mL of a 5 mg/mL solution with phenobarbital, how would you calculate the necessary volume from a 65 mg/mL stock solution?
To prepare 30 mL of a 5 mg/mL solution with phenobarbital, how would you calculate the necessary volume from a 65 mg/mL stock solution?
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What is the method for calculating the amount of a component needed in alligation alternate?
What is the method for calculating the amount of a component needed in alligation alternate?
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When calculating the amount of diluent to prepare a specific concentration, which aspect is often overlooked?
When calculating the amount of diluent to prepare a specific concentration, which aspect is often overlooked?
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What is the primary reason for using a stock solution in pharmaceutical preparations?
What is the primary reason for using a stock solution in pharmaceutical preparations?
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Which of the following methods would you use to prepare a solution of greater strength?
Which of the following methods would you use to prepare a solution of greater strength?
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What component primarily acts as a diluent in pharmaceutical preparations?
What component primarily acts as a diluent in pharmaceutical preparations?
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If you have a 1:5000 w/v solution and need to prepare a larger volume, what is a necessary consideration?
If you have a 1:5000 w/v solution and need to prepare a larger volume, what is a necessary consideration?
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In the process of reducing the strength of a preparation, which method would be ineffective?
In the process of reducing the strength of a preparation, which method would be ineffective?
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When calculating the amount of active constituent needed for dilution, what step is crucial?
When calculating the amount of active constituent needed for dilution, what step is crucial?
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How is the percentage strength of a solution commonly expressed in pharmaceuticals?
How is the percentage strength of a solution commonly expressed in pharmaceuticals?
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In a 1:400 w/v stock solution, how is the concentration defined?
In a 1:400 w/v stock solution, how is the concentration defined?
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When performing alligation medial, what information is essential to complete the calculation?
When performing alligation medial, what information is essential to complete the calculation?
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What is a common misuse of diluents in preparing pharmaceutical products?
What is a common misuse of diluents in preparing pharmaceutical products?
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What is the purpose of alligation medial in pharmaceutical calculations?
What is the purpose of alligation medial in pharmaceutical calculations?
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In preparing a 1:2500 w/v solution from a 1:750 w/v solution, what must be calculated?
In preparing a 1:2500 w/v solution from a 1:750 w/v solution, what must be calculated?
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When mixing various strengths of solutions, what should be ignored in order to calculate final concentration accurately?
When mixing various strengths of solutions, what should be ignored in order to calculate final concentration accurately?
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How do you determine the amount needed of two components using alligation alternate?
How do you determine the amount needed of two components using alligation alternate?
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What is one challenge when calculating the final concentration of alcohol in a mixed solution?
What is one challenge when calculating the final concentration of alcohol in a mixed solution?
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What calculation would you perform to determine the final percentage of zinc oxide in a mixed ointment?
What calculation would you perform to determine the final percentage of zinc oxide in a mixed ointment?
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Which method is least effective in calculating the required amount of stock solution for dilution?
Which method is least effective in calculating the required amount of stock solution for dilution?
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When preparing a mouthwash that contains a specific concentration of dye, what is the first step?
When preparing a mouthwash that contains a specific concentration of dye, what is the first step?
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When mixing solutions of different alcohol percentages, what is crucial for an accurate final concentration?
When mixing solutions of different alcohol percentages, what is crucial for an accurate final concentration?
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Study Notes
Altering Product Strength
- Altering product strength involves dilution, concentration, or fortification.
- Product strength can be increased or decreased by changing the proportion of active ingredient to the whole.
- Strengthening a preparation can be done by adding active ingredient, mixing with a stronger preparation, or evaporating the vehicle (if liquid).
- Decreasing strength can involve adding a diluent or mixing with a weaker preparation.
Stock Solutions
- Stock solutions are solutions of known concentration.
- They are used for convenience in dispensing.
- Stock solutions are often strong solutions to make weaker solutions.
- Stock solutions are usually a strong solution from which weaker ones can be made conveniently.
Diluents
- Diluents are substances added to pharmaceutical products to reduce strength.
- Common diluents are sterile water and petrolatum.
- Diluents usually have no drug substance.
Alligation
- Alligation is a method for mixing solutions or solids.
- Alligation medial calculates the mixture's weighted average.
- Alligation alternate calculates the parts of different components for mixtures of desired strength.
- Alligation uses crosswise subtraction to determine the amounts of each component.
- Alligation involves calculating the mixture of ingredients with different percentage strengths.
Calculations Using Alligation and Inverse Proportion
- Inverse proportion equations (C1 x Q1 = C2 x Q2) are used for concentration and quantity problems.
- The method involves determining the quantity of active constituent (solute) needed.
- This is followed by calculating the quantity of available solutions.
- Percentage strengths are often converted to decimals before calculation.
- Proportional parts in calculations are often reduced to lowest terms.
- Ratio strengths are converted to percentage form for easier calculations.
Examples/Calculations
- Examples demonstrate diluting and making concentrated solutions using provided formulas and data. (e.g., specific volume and percentage strengths)
- Example problems feature alligation, including calculating the percentage strength of a mixture and determining mixing proportions.
- Examples include calculations for various pharmaceutical preparations (e.g., methyl salicylate, aluminum acetate, ammonia, phenylmercuric acetate, ephedrine sulfate, hydrocortisone, benzalkonium chloride, alcohol mixtures, coal tar ointments).
- Examples presented include calculations for both volume and weight-based systems.
- Examples show how to calculate the amount of a stock solution needed to create a desired concentration, and how to calculate the amount of diluent needed.
- The examples highlight the important distinction between using alligation medial and alligation alternate.
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Description
Test your knowledge on altering product strength, stock solutions, and the concept of alligation. This quiz covers essential calculations involving dilution, concentration, and inverse proportions in pharmaceuticals.
