AAPS PharmSciTech

, Volume 7, Issue 4, pp E125–E132 | Cite as

Scale-up of a pan-coating process

  • Preetanshu Pandey
  • Richard Turton
  • Nitin Joshi
  • Elizabeth Hammerman
  • James Ergun


The purpose of this work was to develop a practical scale-up model for a solvent-based pan-coating process. Practical scale-up rules to determine the key parameters (pan load, pan speed, spray rate, air flow) required to control the process are proposed. The proposed scale-up rules are based on a macroscopic evaluation of the coating process. Implementation of these rules does not require complex experimentation or prediction of model parameters. The proposed scale-up rules were tested by conducting coating scale-up and scale-down experiments on 24-inch and 52-inch Vector Hi-coaters. The data demonstrate that using these rules led to similar cumulative drug release profiles (f2≫50; and P Analysis of Variance [P ANOVA]≫0.05 for cumulative percentage of drug released after 12 hours [Cum 12] from tablets made at 24- and 52-inch scales. Membrane characteristics such as opacity and roughness were also similar across the 2 scales. The effects of the key process variables on coat weight uniformity and membrane characteristics were also studied. Pan speed was found to be the most significant factor related to coating uniformity. Spray droplet size was found to affect the membrane roughness significantly, whereas opacity was affected by the drying capacity.


Pan coating scale-up scale-down similarity solvent coating drug release opacity 


  1. 1.
    Edward PL, Atiemo-Obeng VA, Kresta SM, eds.. Handbook of Industrial Mixing: Science and Practice. Hoboken, NJ: John Wiley & Sons; 2004.Google Scholar
  2. 2.
    Stetsko G, Banker GS, Peck GE. Mathematical modeling of an aqueous film coating process. Pharm Technol. 1983;7:50–62.Google Scholar
  3. 3.
    Liu L, McCall T, Tendolkar A. The Scale-up and Process Optimization on an Ethylcellulose-based Functional Coating and Its Impact on In-Vitro/In-Vivo Performance of a Novel Controlled Release System. Paper presented at: 27th International Symposium on Controlled Release of Bioactive Materials; July 7–13, 2000; Paris, France.Google Scholar
  4. 4.
    Porter SC, Verseput RP, Cunningham CR. Process optimization using design of experiments. Pharm Technol. 1997;21:60–70.Google Scholar
  5. 5.
    Rege BD, Gawel J, Kou JH. Identification of critical process variables for coating actives onto tablets via statistically designed experiments. Int J Pharm. 2002;237:87–94.CrossRefPubMedGoogle Scholar
  6. 6.
    Levin M. How to scale up scientically: scaling up manufacturing process. Pharm Technol. 2005;3:4s-12s.Google Scholar
  7. 7.
    Ding YL, Forster RN, Seville JPK, Parker DJ. Scaling relationships for rotating drums. Chem Eng Sci. 2001;56:3737–3750.CrossRefGoogle Scholar
  8. 8.
    Frisbee SE, Mehta K, McGinity J. Processing factors influence the in vitro and in vivo performance of film-coated drug delivery systems. Drug Deliv. 2002;2:72–76.Google Scholar
  9. 9.
    Pondell R. Scale-up of film coating processes. In: Pharm Technol. vol. 6. 1985:S68.Google Scholar
  10. 10.
    Avis KE, Shukla AJ, Chang RK, eds. Pharmaceutical unit operations: coating. Drug Manufacturing Technology Series, vol. 3. Boca Raton, FL: Interpharm/CRC; 1998.Google Scholar
  11. 11.
    Turton R, Cheng XX. The scale-up of spray coating processes for granular solids and tablets. Powder Technol., 2005; 150:78–85.CrossRefGoogle Scholar
  12. 12.
    Porter SC. Scale-up of film coating. In: Levin M, ed. Pharmaceutical Process Scale-Up. New York, NY: Marcel Dekker Inc; 2000:259–310.Google Scholar
  13. 13.
    Henein H, Brimacombe JK, Watkinson AP. Experimental study of transverse bed motion in rotary kilns. Metall Trans B. 1983;14:191–205.CrossRefGoogle Scholar
  14. 14.
    Wang RH, Fan LT. Methods for scaling-up. Chem Eng. 1974;27:88–94.Google Scholar
  15. 15.
    Block L. Scale-up of liquid and semisolid manufacturing processes: scaling up manufacturing process. Pharm Technol. 2005;3:26s-33s.Google Scholar
  16. 16.
    Tatterson GB. Scaleup and Design of Industrial Mixing Processes. New York, NY: McGraw Hill; 1994.Google Scholar
  17. 17.
    Orpe AV, Khakhar DV. Scaling relations for granular flow in quasi-two-dimensional rotating cylinders. Phys Rev E. 2001;64:31302–31315.CrossRefGoogle Scholar
  18. 18.
    Campbell RJ, Sackett GL. Film Coating. In: Avis KE, Shukla AJ, Chang R, eds. Pharmaceutical Unit Operations: Coating. Boca Raton, FL: Interpharm/CRC; 1998:55–176.CrossRefGoogle Scholar
  19. 19.
    Pandey P, Song Y, Kahiyan F, Turton R. Simulation of particle movement in a pan coating device using discrete element modeling and its comparison with video-imaging experiments. Powder Technol. 2006;161:79–88.CrossRefGoogle Scholar
  20. 20.
    Masters K. Spray Drying: An Introduction to Principles, Operational Practices, and Applications. New York, NY: Wiley; 1976.Google Scholar
  21. 21.
    Lefebvre AH. Atomization and Sprays. New York, NY: Taylor and Francis; 1989.Google Scholar
  22. 22.
    Ebey GC. A thermodynamic model for aqueous film-coating. Pharm Technol. 1987;4:1–6.Google Scholar
  23. 23.
    Ende M, Berchielli A. A thermodynamic model for organic and aqueous tablet film coating. Pharm Dev and Tech. 2005;1:47–58.CrossRefGoogle Scholar
  24. 24.
    Sandadi S, Pandey P, Turton R. In-situ, near real-time acquistion of particle motion in a rotating pan coating equipment using imaging techniques. Chem Eng Sci. 2004;59:5807–5817.CrossRefGoogle Scholar
  25. 25.
    Pandey P, Turton R. Movement of different shaped particles inside a pan coating device using novel video imaging techniques. AAPS Pharm Sci Tech. 2005;6:E237-E244.CrossRefGoogle Scholar
  26. 26.
    Joshi N, Hammerman E, Wiryo S, Tuttle W, Ergun J, Lilly B. Controlling tablet surface texture in pan coating processes [abstract]. AAPS J [serial online]. 2004; Available at: http://www.aapspharmaceutica. com/search/abstract_view.asp?id=228&ct=04Abstracts.Google Scholar

Copyright information

© American Association of Pharmaceutical Scientists 2006

Authors and Affiliations

  • Preetanshu Pandey
    • 1
  • Richard Turton
    • 1
  • Nitin Joshi
    • 2
  • Elizabeth Hammerman
    • 2
  • James Ergun
    • 2
  1. 1.Department of Chemical EngineeringWest Virginia UniversityMorgantown
  2. 2.Oral Products Research and DevelopmentALZA CorporationMountain View

Personalised recommendations