## How is pharmacy strength ratio calculated?

A liquid ingredient mixed with another liquid vehicle has a concentration of 5% v/v. Find the ratio strength and the amount strength expressed as mL/mL. By ‘spotting’ we can see that: r = 100 5 = 20 a = 5 100 = 0.05 The ratio is 1 in 20 v/v and the amount strength in mL/mL is 0.05 mL/mL.

## How do you calculate dilution in pharmacy?

Pharmacy Dilution Math is a process of reducing the concentration of a solution by adding more solvent….

- The Equation Set-up: 1500(.20) + X (0.00) = (1500 + X).12.
- Do the math: 1500(.20) + X (0.00) = (1500 + X).12. 300 = 180 + .12X. 120 = .12X.
- Isolate for “X”: 120. = .12x. .12. .12.
- Solution:

**How do you calculate days supply for estradiol cream?**

Using a conversion factor of 20 drops per milliliter, calculate the days’ supply by dividing the total number of drops dispensed by the number of drops required for each day’s dose.

**How do you calculate the number of doses?**

D/H x Q = x, or Desired dose (amount) = ordered Dose amount/amount on Hand x Quantity.

### How are pediatric drug doses calculated?

Care must be taken to properly convert body weight from pounds to kilograms (1 kg= 2.2 lb) before calculating doses based on body weight….Example 2.

Step 1. Calculate the dose in mg: | 18 kg × 100 mg/kg/day = 1800 mg/day |
---|---|

Step 2. Divide the dose by the frequency: | 1800 mg/day ÷ 1 (daily) = 1800 mg/dose |

### How do you convert mg/mL to ratio?

To convert product ratio strengths to mg/mL, divide the ratio strength by 1000. l Example: Convert 1:10000 (w/v) to mg/mL. l 10000 ÷ 1000 =1 mg/10 mL, answer.

**How do you calculate pharmaceutical calculations?**

How to ace pharmacy calculations

- Work efficiently.
- Draw out the key points.
- Know the units and conversions.
- Check the final answer makes sense.
- Round the answer at the correct time.
- Extract and interpret the right information.
- Formulae to memorise.
- Practice weaker points.

**How do you dilute a drug?**

In terms of dilution, 1% is the same as a 1:100 solution dilution.

- So, if there is 1g per 100mls there is also 1000mg per 100mls.
- If we divide this down there will be 10mg in 1ml.
- 5ml of lidocaine will have 5 x 10mg = 50mg in a 5ml vial.

## How do you calculate prescription days?

For oral solids, including tablets and capsules, the day’s supply calculation is fairly straightforward—if a patient is taking metformin 500 mg twice daily, dividing the quantity prescriber by the number of doses taken per day would give you the day’s supply.

## Where do you rub estrogen cream?

Carefully spread the cream onto the top wall of the vagina just underneath the urethral area (see Figure 2, yellow highlighted area). As the cream is spread, some may be gently inserted into the vagina: however, it is not necessary to push the cream high into the vagina.