What factors are related to the excessive or insufficient hardness of tablets?

What factors are related to the excessive or insufficient hardness of tablets?

The influencing factors of abnormal tablet hardness (excessive or insufficient) can be summarized as follows:

‌I. Main Causes of Excessive Hardness‌

‌Excessive Compression Force‌

When pressure exceeds the critical value, particles bond too tightly, leading to high hardness or even tablet cracking.

‌Overuse of Binders‌

Binders (e.g., hydroxypropyl methylcellulose) enhance inter-particle bonding, but excessive use can hinder tablet disintegration.

‌Improper Moisture Control‌

High moisture content in particles forms "solid bridges" after drying, significantly increasing hardness.

‌Suboptimal Excipient Selection‌

Excessive plastic excipients (e.g., microcrystalline cellulose) improve compressibility.

Insufficient lubricants (e.g., magnesium stearate) increase inter-particle friction.

‌II. Main Causes of Insufficient Hardness‌

‌Insufficient Compression Force‌

Loose particle bonding directly results in substandard hardness.

‌Inadequate or Ineffective Binders‌

Poor inter-particle bonding, especially for drugs with low compressibility (e.g., fibrous herbal powders).

‌Excessive Lubricants‌

Hydrophobic lubricants (e.g., >1% magnesium stearate) coat particle surfaces, weakening bonding.

‌Process Defects‌

Over-drying causes loss of crystalline water, reducing adhesiveness.

Uneven particle size distribution and excessive fines impair compression.

‌III. Other Key Factors‌

‌Elastic Recovery Rate‌: Elastic materials (e.g., rubber) yield low hardness; >15% recovery leads to poor formation.

‌Compression Speed‌: Slow compression enhances particle bonding; high-speed presses require parameter adjustments.

‌IV. Solution References‌

‌Excessive Hardness‌: Reduce binder dosage, lower compression force, and add disintegrants (e.g., sodium carboxymethyl starch).

‌Insufficient Hardness‌: Optimize binder concentration, increase compression force, and control lubricant proportion.

ST220 tablet hardness tester is a special instrument used to test the hardness of tablets. This instrument is suitable for the hardness test of tablets and is a necessary instrument for laboratories of pharmaceutical factories, pharmaceutical teaching and research, scientific research and drug testing departments.

Automatic Tablet Hardness Tester with Printer

Medical Digital Automatic Tablet Hardness Tester with Printer

Tablet Hardness Tester(Automatic Type with Printer)

Automatic Tablet Hardness Tester with Printer