From the following formula or 40 sertraline hydrochloride capsules, calculate the quantity o each ingredient needed to prepare 250 such capsules.

Question

(involving reducing and enlarging formula)

Sertraline hydrochloride 300 mg

Silica gel 6 g

Calcium citrate 4 g

Answer 1

You can do this a number of ways. I'll show you only 2 of them.

1). You can simply ask how many times 40 goes into 250, and you find it to be 250 / 40 = 6.25. So you would need 6.25 times the amount of each ingredient to make 250 capsules as you would to make the 40 capsules.

Thus...

Sertraline HCl = 300 mg x 6.25 = 1875 mg = 1.875 g

Silica gel = 6 g x 6.25 = 37.5 g

Calcium citrate = 4 g x 6.25 = 25 g

2). Use dimensional analysis

Sertraline HCl: 300 mg / 40 caps x 250 caps = 1875 mg = 1.875 g

Silica gel: 6 g / 40 caps x 250 caps = 37.5 g

Calcium citrate: 4 g / 40 caps x 250 caps = 25 g