If a doctor orders a hydrocortisone treatment at 2.5% concentration, how much hydrocortisone would be required for 100 g of cream?

To determine how much hydrocortisone is required for a 2.5% concentration in a 100 g cream formulation, you can use the percentage concentration to calculate the amount of the active ingredient.

The term "2.5% concentration" means that there are 2.5 grams of hydrocortisone in every 100 grams of cream. This can be calculated using the formula:

[

\text{Amount of hydrocortisone} = \left(\frac{\text{percentage}}{100}\right) \times \text{total weight of the cream}

]

Substituting the values:

[

\text{Amount of hydrocortisone} = \left(\frac{2.5}{100}\right) \times 100 , \text{g}

]

Calculating this gives:

[

\text{Amount of hydrocortisone} = 2.5 , \text{g}

]

Therefore, for a cream weighing 100 g at a 2.5% concentration, you need 2.5 g of hydrocortisone, which confirms the correct answer. This reasoning illustrates the direct relationship between the concentration percentage, the total weight of the