Dissolution Testing of Chewable Tablets

MHRA asks for a dissolution test because a chewable tablet is still an oral solid dosage form, and chewing cannot be assumed to be complete or consistent in every patient.

Main reasons:

• Some patients may swallow the tablet whole or only partially chew it.
• Chewing varies considerably between patients.

Tablet hardness, compression force, granulation, API particle size and excipient grade can affect drug release.

Disintegration only shows that the tablet breaks apart; it does not demonstrate that the active ingredient becomes dissolved or available.

Dissolution provides a routine batch-release and stability test that can detect meaningful manufacturing or formulation changes.

For a generic product, it helps connect the commercial batches with the biobatch and supports comparative performance against the reference product.

FDA’s chewable-tablet guidance also identifies hardness, disintegration and dissolution as separate critical quality attributes, which supports MHRA’s scientific position. FDA—Quality Attribute Considerations for Chewable Tablets⁠.

What MHRA will generally expect?
For an immediate-release chewable tablet, you should normally provide:

• A dissolution method-development report.
• Solubility data across physiologically relevant pH conditions.
• Selection and justification of apparatus, medium, volume, rpm and sampling time.
• Evidence that the method is discriminatory.

Comparative dissolution profiles for the test and reference products, normally in:

• pH 1.2
• pH 4.5
• pH 6.8
• Proposed QC medium

A justified finished-product specification based on development, biobatch, validation, stability and commercial-scale data.

Dissolution data on the intact tablet, because swallowing without adequate chewing represents a foreseeable mode of administration.

EMA guidance similarly treats dissolution as an important quality and performance control for generic immediate-release oral products. EMA—Dissolution specification for generic oral immediate-release products⁠

If this is an alginate–antacid chewable tablet, For a locally acting product containing sodium alginate, sodium bicarbonate and calcium carbonate, conventional API dissolution may not fully represent clinical performance. Tests such as the following may be more mechanistically relevant:

• raft formation time;
• raft strength and weight;
• acid-neutralising capacity;
• neutralisation profile;
• release of calcium or carbonate;
• disintegration after chewing simulation;
• viscosity or gel characteristics.

However, this does not automatically eliminate dissolution. You would need to demonstrate scientifically that conventional dissolution provides little meaningful information and that the proposed alternative tests better control the product’s mechanism of action. A combined approach—dissolution or release testing plus raft/acid-neutralisation testing—is usually easier to defend.

Read also: How Do You Choose an RPM in Dissolution?