1. What is Alligation Method?

The alligation method is a mathematical technique used in pharmacy to calculate the proportions of different strength solutions needed to prepare a solution of intermediate strength. It's particularly useful when compounding medications.

2. How Does the Calculator Work?

The calculator uses the alligation method formulas:

Where:

• All values are expressed as percentages (%)
• Higher Strength must be greater than Desired Strength
• Desired Strength must be greater than Lower Strength

Explanation: The method calculates the ratio needed between two different strength solutions to achieve a desired intermediate strength.

3. Importance of Alligation in Pharmacy

Details: Alligation is essential for accurate medication compounding, especially when preparing custom strength solutions from available stock solutions.

4. Using the Calculator

Tips: Enter the higher and lower percentage strengths available, the desired percentage strength, and optionally the total quantity needed. The calculator will show the ratio and exact quantities if total is provided.

5. Frequently Asked Questions (FAQ)

Q1: When should I use alligation method?
A: Use it when you need to prepare a specific strength solution from two different strength solutions of the same medication.

Q2: Can I use this for solid medications?
A: The method is primarily for liquid preparations, but the same ratio concept can be applied to solids in some cases.

Q3: What if my desired strength is outside the range?
A: The method only works for intermediate strengths. For strengths outside your available range, you'll need different stock solutions.

Q4: How precise is this method?
A: It's mathematically precise, but always double-check calculations and measure carefully when compounding.

Q5: Can I use different units than percentages?
A: Yes, as long as all strengths use the same units (e.g., mg/mL), the ratios will be the same.