To determine the amount of triamcinolone needed to prepare the ointment, we first need to calculate the total amount of triamcinolone needed for the entire prescription.
The prescription is for 120g of ointment, and the concentration of triamcinolone needed is 0.051%. This means that for every 100g of ointment, we need 0.051g (or 51mg) of triamcinolone.
To find out how much triamcinolone we need for the entire prescription, we can use the following calculation:
Total triamcinolone needed = 0.051g/100g x 120g = 0.0612g
Now that we know how much triamcinolone we need, we can use the concentration of the injection to determine how much we need to draw up.
The injection contains 40mg of triamcinolone per ml. Therefore, we can use the following calculation to determine how much of the injection we need:
Amount of injection needed = Total triamcinolone needed / concentration of injection
Amount of injection needed = 0.0612g / 40mg per ml = 1.53 ml
Therefore, we would need 1.53 ml of the injection containing 40mg of triamcinolone per ml to prepare the prescription for triamcinolone 0.051% ointment base ad 120g.