Hi Mohamed Khashan

Coating a tablet with a lipid-based material like wax dissolved in triglyceride can indeed result in a waxy texture. To refine your approach, you might consider alternative coating materials or adjustments to your process to achieve a more desirable end product. Perform small level experiment with different materials and methods in small quantities to evaluate performance. Check the coated tablets for texture, hardness, and finish. Ensure the coating remains intact under storage conditions.

Suggestions for Improving Tablet Coating:

1. Modify the Lipid Coating Formulation

• Blend Waxes: Mix wax with less waxy lipids, such as phospholipids or MCT, to reduce the waxy feel.
• Use Emulsifiers: Incorporate emulsifiers like lecithin to enhance smoothness and uniformity.
• Reduce Wax Concentration: Lower the percentage of wax in the solution to make the coating thinner and less waxy.

2. Adjust Process Parameters

• Spray Application: Use a fluid bed coater or pan coater to apply the coating evenly in thin layers.
• Drying Conditions: Ensure proper drying with controlled heat or airflow to prevent excessive buildup of wax.
• Solution Temperature: Maintain the solution temperature to avoid premature solidification of wax.

3. Consider Functional Coatings

• Barrier Coating: Apply a thin polymer base coat before the wax coating to minimize waxy texture while retaining functionality.
• Taste Masking: Add flavoring agents or a secondary smooth coating over the wax.

4. Test Different Lipid Systems

• Use Glycerides with Higher HLB: Choose lipid systems with higher HLB to reduce waxiness.
• Use Structured Lipids: Try structured triglycerides that provide controlled melting and less waxy residues.

5. Apply a Dual Coating System

• First Layer: Use a water-based polymer to create a smooth surface.
• Second Layer: Apply a very thin layer of the wax coating for moisture protection or desired functionality.

6. Switch to Alternate Coating Materials

• Film-forming Polymers: Use polymers like HPMC, EC, or PVA. These create a smooth, non-waxy coating.
• Aqueous Coatings: Formulate water-based dispersions of coating materials like Eudragit or cellulose derivatives.
• Enteric Coatings: Use materials like CAP if you want delayed-release properties.