Pharmacy Calculation

[J Hiesenberg14]

Manufacturer’s directions call for the addition of 90 mL of water to constitute a 150- mL container of cefaclor to yield a strength of 250 mg of cefaclor per 5 mL. If 60 mL of water were mistakenly added in consti- tuting the product, calculate the resultant milligrams of cefaclor per 5 mL.

Please explain
The ans is 312.5 mg

I did : 250 * 210 =52500/150 =350

 

[Reirrac]

Powder volume: 150 ml - 90 ml = 60 ml
Cefaclor amount: 250 mg/5 ml * 150ml = 7500 mg

New Volume: 60 ml + 60 ml = 120 ml
New Strength: 7500 mg/120 ml = 62.5 mg/ml = 312.5 mg/5ml

 

[trailerpark]

I would throw away the old bottle, grab a new one and add the water myself.

 

[owlegrad]

I would throw away the old bottle, grab a new one and add the water myself.

Why not add 30 more ml of water?

Anyway that has nothing to do with the question.