78. A 200 g compounded ointment contains 10 g of active ingredient. Which of the following strengths should the pharmacy technician place on the prescription label?
Answer: B
5%
The strength of the compounded ointment is calculated by determining the ratio of the active ingredient to the total weight of the ointment. With 10 g of active ingredient in a 200 g ointment, the strength is 5%.
A) 10%
This option is incorrect because a 10% strength would imply that there are 10 g of active ingredient in every 100 g of ointment, which does not reflect the actual ratio in this case.
B) 5%
This option is correct as it accurately represents the strength of the ointment. The calculation shows that the active ingredient (10 g) constitutes 5% of the total weight (200 g) of the ointment.
C) 20%
This option is incorrect because a 20% strength would mean there should be 20 g of active ingredient per 100 g of ointment. Since there are only 10 g in a total of 200 g, this percentage is not achievable.
D) 25%
This option is also incorrect as a 25% strength would require 25 g of active ingredient per 100 g of ointment. The actual amount of active ingredient (10 g) is insufficient to justify this percentage.
Conclusion
The correct strength of the compounded ointment is 5%, reflecting the actual proportion of active ingredient to total weight. All other options are incorrect as they misrepresent the concentration based on the given quantities. The accurate calculation confirms that only option B aligns with the formulation of the ointment.