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Coating uniformity: influence of atomizing air pressure
Susanne Tobiska1, Peter Kleinebudde
1Martin-Luther-University Halle-Wittenberg, Institute of Pharmaceutics and Biopharmaceutics, Halle, Germany.
Pharmaceutical Development and Technology
|April 1, 2003
Summary
Increasing atomizing air pressure improves tablet coating uniformity and smoothness. However, higher pressures increase spray loss, requiring more polymer for enteric coatings.
Area of Science:
- Pharmaceutical Technology
- Materials Science
Background:
- Film coating is crucial for tablet quality and drug delivery.
- Optimizing coating parameters ensures uniformity and desired film properties.
Purpose of the Study:
- To evaluate the impact of atomizing air pressure on film coating uniformity.
- To assess how atomizing air pressure affects film coat quality and properties.
Main Methods:
- Utilized a Walther Pilot spray gun and Bohle BLC 5 drum coater.
- Investigated four atomizing air pressures (0.5–2.0 bar) while keeping other parameters constant.
- Measured coating uniformity via mass variance and film thickness variance.
Main Results:
- Higher atomizing air pressure resulted in smoother tablets with reduced mass variance.
- Increased atomizing air pressure led to greater spray loss.
- A higher minimum polymer amount was needed for enteric coating at 2.0 bar atomizing air pressure.
Conclusions:
- Atomizing air pressure is a significant factor in achieving uniform and high-quality film coatings.
- Optimizing atomizing air pressure is essential for balancing coating uniformity and material efficiency.
- Higher pressures necessitate adjustments in polymer quantity for effective enteric coating.
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