Pharmacy Technician Certification Board Practice Exam

To compound 100 g of triamcinolone 0.1% cream using a 3% cream, what quantity of 3% cream is required?

1. 0.3 g

2. 3.3 g

3. 33 mg

4. 33 g

The correct answer is: 3.3 g

To determine the amount of 3% triamcinolone cream needed to prepare 100 g of a 0.1% triamcinolone cream, we can apply the concept of dilution and concentration. First, let's look at what 0.1% means in this context. A 0.1% cream means there are 0.1 g of triamcinolone in every 100 g of cream. For 100 g of a 0.1% cream, the total amount of triamcinolone that needs to be present is 0.1 g. Now, we have a 3% cream which contains 3 g of triamcinolone in every 100 g of cream. To find out how much of the 3% cream we need to obtain 0.1 g of triamcinolone, we can set up the following equation: Let \( x \) be the amount of 3% cream needed (in grams). The amount of triamcinolone in \( x \) grams of 3% cream can be expressed as: \[ \text{Amount of triamcinolone} = 0.03x \] We want this to equal 0.1 g