Arrange the following preparations in increasing order of their resisting area
**Core Concept**
The question is testing the student's understanding of the concept of resistance area, which is a measure of the surface area of a preparation that is exposed to the body's tissues, affecting the absorption rate of a drug. The resistance area is an important factor in the pharmacokinetics of topical preparations.
**Why the Correct Answer is Right**
The correct arrangement of preparations in increasing order of their resistance area is based on the physical characteristics of each preparation. The resistance area is inversely proportional to the surface area of the preparation that is exposed to the body's tissues. Therefore, the preparation with the smallest surface area will have the highest resistance area, and the arrangement should reflect this.
* **Option A:** Creams have a large surface area due to their semi-solid consistency, making them have the lowest resistance area.
* **Option B:** Ointments have a larger surface area than creams, but smaller than lotions, making them have a moderate resistance area.
* **Option C:** Lotions have a larger surface area than ointments, making them have a moderate to high resistance area.
* **Option D:** Gels have a smaller surface area than lotions, making them have the highest resistance area.
**Why Each Wrong Option is Incorrect**
* **Option A:** Creams have a larger surface area than ointments, making them have a lower resistance area.
* **Option B:** Ointments have a larger surface area than creams, but smaller than lotions, making them have a lower resistance area than lotions.
* **Option C:** Lotions have a larger surface area than ointments, making them have a lower resistance area than ointments.
**Clinical Pearl / High-Yield Fact**
A memorable fact is that the resistance area of a preparation is inversely proportional to its surface area, which affects the absorption rate of a drug. This is an important consideration when selecting topical preparations for therapeutic use.
**Correct Answer: D. Gels have the highest resistance area due to their smaller surface area.