pharmacy calculations
posted by cleondra on .
you need to prepare 180g of a 5% cream using 30% stock cream and a cream base.how much needed of each?

You want to dilute the 30% cream by 30/5 = 6 times so you want 1 part of the 30% cream + 5 parts of the base. How much is 1 part? That's 180/6 = 30 g = 1 part.
5 parts base = 5*30 = 150 g = 5 parts
Total = 6 parts = 180g.