Tablet Hardness Testing

Tablet hardness testing is a crucial quality control step in pharmaceutical manufacturing. It measures the mechanical strength of tablets to ensure they withstand the stresses of production, packaging, shipping, and patient handling. More than a compliance task, tablet hardness testing helps manufacturers control formulation consistency, evaluate production processes, and improve product performance.

Cell Instruments offers precision solutions like the MPT-02 Tablet Hardness Tester to support the evolving needs of quality assurance teams and R&D laboratories.

Why Tablet Hardness Matters in Pharmaceutical Quality Control

Tablet hardness—also referred to as tablet breaking force—is a vital characteristic affecting tablet integrity, disintegration, and dissolution. According to USP <1217>, tablet hardness is not simply a measure of strength; it’s an indicator of the tablet’s ability to resist mechanical stress without compromising therapeutic efficacy.

Key Implications of Tablet Hardness Testing:

• Ensures tablet integrity during coating, packaging, and transport
• Helps optimize formulation during development
• Ensures dosage uniformity and bioavailability
• Complies with regulatory standards like USP <1217>

Core Tablet Testing Methods Under USP <1217>

Tablet Hardness Test (Crushing Strength Method)

The most common approach is the crushing strength method, where a tablet is compressed between two platens until it breaks. The force required is recorded as the kekerasan tablet.

Equation for tensile strength (round tablets):
σ = 2F / (π × D × H)
Where:
F = Breaking force, D = Tablet diameter, H = Tablet thickness

This test is essential for tablets that must endure robust handling without crumbling, particularly during packaging and distribution.

Compression Test

This is a mechanical stress test that mimics the real-world conditions tablets face during packaging and transport. It measures how much compressive force a tablet can tolerate before deformation or breakage.

The MPT-02from Cell Instruments allows controlled compression force, providing accurate and repeatable results.

Tablet Friability Test

Friability testing evaluates a tablet’s resistance to surface wear and chipping. Tablets are tumbled in a rotating drum and then reweighed. The USP <1216> standard recommends a maximum weight loss of 1.0% as acceptable.

This test is essential to ensure tablets remain intact without excessive dusting or cracking.

Three-Point Bending Test

For tablets that are long, oval, or scored, the three-point bending test is more suitable. It measures the tablet breaking force by supporting it at two points while applying pressure at the midpoint until it fractures.

This method is particularly useful for evaluating chewable or scored tablets and is available as an optional feature with the MPT-02 system.

Key Secondary Tests and Parameters

Tablet Thickness: A critical physical parameter affecting uniformity and tensile strength calculations.

Friability of Tablet: Helps identify poorly bonded or overly dry formulations.

Tablet Brittleness Test: Evaluates a tablet’s tendency to fracture under low force or impact.

Tablet Strength: A general term combining compressive and tensile strength parameters to assess durability.

Choosing the Right Tablet Hardness Tester

When selecting a tablet hardness tester, look for precision, reliability, and compliance with pharmacopeial standards.

Why Choose the MPT-02 Tablet Hardness Tester?

Cell Instruments’ MPT-02 offers advanced functionality designed for pharmaceutical quality control:

Its flexible fixture system supports a variety of tablet shapes and sizes, making it ideal for tablets with complex geometries.

Best Practices for Reliable Tablet Hardness Testing

Calibrate testers regularly with traceable weights

Test at consistent loading rates (e.g., ≤ 20 N/s or ≤ 3.5 mm/s)

Use padding for tensile-strength-focused tests (optional)

Ensure consistent tablet orientation during every test

Test at least 6 tablets for statistically meaningful results

Conclusion

Tablet hardness testing plays a pivotal role in pharmaceutical quality control. From evaluating compression strength to ensuring friability compliance, proper hardness analysis ensures patient safety and product reliability. By aligning with USP <1217> and using robust instruments like the MPT-02 Tablet Hardness Tester, pharmaceutical professionals can confidently deliver consistent, high-quality products.

Whether you’re optimizing formulations or performing routine QC, Cell Instruments delivers the testing solutions you can trust.