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X. Parissaux(1), A. Joshi(2), C. Dusautois(1), G. Le Bihan(1) and P. Lefevre (1)
(1) Roquette Frères, Lestrem, France
(2) Roquette America Inc., Keokuk, IA 52632
Introduction
Aqueous film coating is widely used in the pharmaceutical industry for improving organoleptic properties (color/taste/odor), easier brand identification, facilitating swallowing, protection from light and humidity etc.
Many synthetic polymers, predominantly modified celluloses, are the most widely used tablet coating polymers, but suffer from drawbacks such as:
- Strong unwanted taste/odor and yellowish color to the solution
- Difficulty in solubilization due to lumping and foam formation
- “Bearding” on spray nozzles causing frequent production stops for cleaning
- High coating cost per tablet due to cost of polymer and long coating times
An ideal polymer for aqueous tablet coating should provide the following:
- Free flowing, granular nature with immediate solubilization in water
- No lumping or foam formation, neutral color, taste and odor
- High solids loading at low viscosity for rapid coating process
- Excellent film integrity and stability without affecting tablet performance
A specially pregelatinized, new-generation, hydroxypropyl starch polymer(LYCOAT®), ensures low viscosity dispersions at much higher solids content vs.HPMC. The entire coating process can be completed in approx 30min while maintaining a core tablet bed temp of 32°C.
Absence of “bearding” with LYCOAT® minimizes production stops for cleaning.
Excellent film integrity and adhesion provides additional advantage vs. HPMC in aqueous film coating. Data supporting the superiority of LYCOAT® vs. HPMC in aqueous film coating is presented.
Summary and conclusions
The specially pregelatinized, new-generation, hydroxypropyl starch polymer (LYCOAT®), exhibits significant advantages over HPMC in aqueous film coating:
- Free flowing, granular nature with immediate solubilization in water
- Stable solution, no lumping or foam formation, neutral in color, taste and odor
- Significantly lower viscosity even at high solids content
- Lower Tg and higher elasticity allows more flexible and robust film formation
- Spray uniformity and completion of coating in 60% less time than HPMC
- Uniform glossy coating achieved at a low tablet bed temperature of 32oC
- No logo-bridging or infilling observed
- No “bearding” on spray nozzles, minimizing production halt
- Faster coating and minimal production halts allow significant cost-savings
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