# How do you find the minimum Weightable quantity?

## How do you find the minimum Weightable quantity?

Terms in this set (10)

1. single ingredient or a mixture which does not contain any active drug.
2. must be done last (can only be done last)
3. LWQ = (100% x sensitivity requirement (SR)) / (acceptable error %)
4. variation on percent of error equation:
5. mass of the drug that is weighed.
6. – use MWQ/LWQ method to find LWQ (mg)

What is minimum Weighable amount?

Explanation: The minimum weighable quantity in an electronic balance is 1 mg. This may vary from place to place. For example this is for the electronic balance that is used in the groceries shop.

How do you compute for the smallest quantity of a substance that can be weighed on a balance with the desired precision?

Calculate the smallest quantity of a substance that can be weighed on the balance with the desired precision. The equation used: 100% X Sensitivity Requirement (mg) /Acceptable Error (%) = Smallest Quantity (mg)

### How do you calculate balance of sensitivity?

Count the number of graph squares that cause the smallest detectable motion. Multiply that number of squares times the calculated mass of a single square to determine the balance’s sensitivity.

How do you calculate Trituration?

If your dilution is to be 250 g trituration, then, from the above, 1:1000:x:250, x = 250/1000 = 0.25. Therefore the trituration is 0.25:250, but the ratio of the T-3 (“solute”) to the diluent (“solvent”) is 0.25 in 250-0.25, or 249.75.

What is the minimum Weighable amount for powders?

The minimum weighable quantity of a drug powder, usually taken to be 50 mg or 100mg, is mixed with an inert substance to produce a 1:10 or 1:100 dilution. In practice, when making individual powders it is recommended to make in excess to allow for losses.

#### How much is an aliquot?

That is, an aliquot is the fractional part of an entire whole sample. For example, let’s say we have a 20ml solution of salt water (NaCl) and decide that we only want to work smaller 5ml samples.

What is the minimum Weighable quantity on torsion balance?

120 milligrams
The least weighable quantity would be 120 milligrams. The amount of drug substance to be weighed, therefore, must be equal to or greater than 120 milligrams.

What is the minimum amount that can be weighed on a Class A prescription balance with a potential error of not more than 10 %?

The minimum quantity that can be weighed accurately on the Class III (Class A) prescription balance with an error of not more than 5% is 120 mg (assuming a SR of 6 mg).