Question

Choose the correct option to justify the requirement: “Absorbent Cotton Wool IP (Indian Pharmacopoeia) should exhibit rapid sinking time.”

• A. Within 3--6 seconds
• B. Within 7--10 seconds
• C. Within 11--15 seconds
• D. Within 15--20 seconds

Hint:

Absorbent Cotton Wool IP → Rapid Water Absorption → Sinking Time = 7--10 Seconds.

Answer 1

The Correct Option is B

Concept: Absorbent cotton wool is a purified fibrous product obtained from cotton hairs after removal of fatty substances, waxes, coloring matter, and impurities. It is widely used in hospitals, surgical dressings, wound care, and pharmaceutical applications. One of the most important quality control parameters for absorbent cotton wool is its ability to absorb water rapidly. This property is evaluated using the sinking time test. The purpose of the test is to ensure that the cotton has been adequately purified and rendered hydrophilic by removing natural waxes and fatty materials that repel water.

Step 1: Understand the significance of sinking time.
Raw cotton naturally contains waxes, fats, and other hydrophobic substances. These substances prevent rapid wetting and absorption of water. To prepare absorbent cotton wool, these materials are removed through appropriate purification processes. The effectiveness of purification is assessed by measuring sinking time.

Step 2: Understand the principle of the test.
A small quantity of absorbent cotton wool is gently placed on the surface of water. The time required for the cotton to become completely wet and sink below the surface is recorded. Rapid sinking indicates good absorbency and proper purification.

Step 3: Apply the Indian Pharmacopoeial requirement.
According to pharmacopoeial standards, absorbent cotton wool should exhibit rapid wetting and sinking characteristics. The prescribed acceptable sinking time is within 7--10 seconds. This ensures adequate absorbency for medical and surgical applications.

Step 4: Analyze the incorrect options.
A sinking time of 3--6 seconds is excessively rapid and is not the specified pharmacopoeial requirement. Times of 11--15 seconds and 15--20 seconds indicate slower wetting and inferior absorbency. Such values would not satisfy the required standard.

Step 5: Select the correct option.
The pharmacopoeial requirement clearly specifies a sinking time within 7--10 seconds. Conclusion: Absorbent Cotton Wool IP should exhibit rapid sinking within 7--10 seconds to ensure proper absorbency and quality. Therefore, the correct answer is Option (B).