Coating uniformity and coating efficiency in a Bohle Lab-Coater using oval tablets

Area of Science:

• Pharmaceutical Technology
• Materials Science
• Chemical Engineering

Background:

• Coating uniformity is critical for drug efficacy and safety.
• Optimizing tablet coating processes requires understanding the impact of various operational parameters.
• Enteric coating provides targeted drug release and protects against gastric degradation.

Purpose of the Study:

• To investigate the influence of tablet size, batch size, pan speed, and rotation axis inclination on coating uniformity and efficiency.
• To determine the optimal parameters for achieving uniform enteric coatings.
• To evaluate the relationship between process variables and coating performance in a Bohle Lab-Coater BLC 5.

Main Methods:

• Utilized two different sized oval tablets for coating experiments.
• Assessed coating uniformity via mass variance, acetaminophen dissolution, and minimum polymer for enteric coating.
• Employed a Bohle Lab-Coater BLC 5 for controlled tablet coating.

Main Results:

• Mass variance decreased with increased pan speed, showing linear and quadratic effects for small and large tablets, respectively.
• Minimum polymer required for gastric resistance was dependent on pan speed for both tablet sizes.
• Acetaminophen dissolution was linearly influenced by batch size and, for large tablets, also by pan speed and axis inclination.

Conclusions:

• Pan speed significantly impacts tablet coating uniformity and the polymer amount needed for gastric resistance.
• Batch size and pan speed are key factors influencing drug release profiles from enteric-coated tablets.
• No clear correlation was found between coating process efficiency and the investigated variables.