Tablet Friability Procedure Guide

Learn the Tablet Friability Procedure, steps, limits, and USP criteria to ensure tablet durability and quality.

Tablet Friability Procedure: Complete Guide

The Tablet Friability Procedure is a critical quality control test used in pharmaceutical manufacturing to evaluate the mechanical strength of tablets. It determines how well tablets can withstand abrasion, shock, and handling during packaging, transport, and use.

This guide explains the procedure step by step, along with acceptance criteria and practical considerations to ensure compliance with USP standards.

What Is Tablet Friability?

Tablet friability refers to the tendency of a tablet to chip, crumble, or break under mechanical stress. The Tablet Friability Procedure helps ensure tablets remain intact from production to patient use.

Sample Selection Criteria

The number of tablets used depends on their individual weight:

• Tablets ≤ 650 mg:
  Select a sample equivalent to approximately 6.5 g.
• Tablets > 650 mg:
  Use 10 whole tablets.

Before testing, tablets must be carefully dedusted to remove any loose particles that could affect accuracy.

Step-by-Step Tablet Friability Procedure

1. Weigh the Sample
   Accurately record the initial weight of the dedusted tablets.
2. Place in Friabilator
   Transfer the tablets into the drum of the friabilator.
3. Run the Test
   Rotate the drum 100 times at 24–26 rpm.
4. Remove and Dedust Again
   After rotation, remove tablets and eliminate any loose dust.
5. Final Weighing
   Accurately weigh the tablets again.

6. Calculate Weight Loss
   Determine percentage weight loss using:

   $$\text{Friability (\%)}=\frac{\text{Initial Weight - Final Weight}}{\text{Initial Weight}}\times 100$$

Acceptance Criteria

• A weight loss of not more than 1.0% is generally considered acceptable.
• If cracked, broken, or cleaved tablets are observed, the sample fails immediately.
• For unclear results or weight loss exceeding limits:
  • Repeat the test twice more
  • Calculate the mean of three tests

Note: Effervescent and chewable tablets may have different friability limits.

Special Considerations

1. Tablet Shape and Size

If tablets do not tumble properly:

• Adjust the drum to an angle of ~10°
• Ensure tablets do not stick together and can fall freely

2. Hygroscopic Tablets

• Perform testing in a controlled humidity environment
• Prevent moisture-related weight changes

3. Equipment Variations

• Friabilators with dual drums or multiple compartments can be used
• Suitable for testing multiple samples simultaneously

Importance of Tablet Friability Procedure

The Tablet Friability Procedure ensures:

• Product durability during handling
• Compliance with pharmacopeial standards
• Consistent drug delivery
• Reduced product loss and recalls

Frequently Asked Questions (FAQs)

1. What is the purpose of the Tablet Friability Procedure?

It measures the ability of tablets to resist mechanical stress and abrasion.

2. What is the acceptable friability limit?

Typically, not more than 1.0% weight loss is acceptable.

3. How many rotations are used in friability testing?

The drum rotates 100 times at 24–26 rpm.

4. Why is dedusting important before testing?

It removes loose particles that could falsely increase weight loss.

5. What happens if tablets break during testing?

The sample fails immediately if tablets are cracked or broken.

6. When should the test be repeated?

If results are unclear or exceed limits, repeat the test two more times.

7. How is friability calculated?

By comparing initial and final weights and expressing the loss as a percentage.

8. Are all tablets tested the same way?

No, effervescent and chewable tablets may have different criteria.

9. Why control humidity for hygroscopic tablets?

To prevent moisture absorption affecting test accuracy.

10. What if tablets do not tumble properly?

Adjust the drum angle (around 10°) to ensure free movement.