title: Understanding the thermodynamic micro-environment inside a pan coater using a data logging device.
abstract: OBJECTIVE
  The objective of the current study was to establish the use of PyroButton data-logging device to monitor and quantify the thermodynamic environment (temperature and humidity) of a pan coating process.
  
  
  METHODS
  PyroButtons were placed (fixed) at various locations in a pan coater, including exhaust plenum, spray-gun bar, baffles and were also allowed to freely move with the tablet-bed. A full factorial design of experiments (DOE) study on three process parameters, exhaust temperature, pan speed and spray rate was conducted on a 24 inch pan coater, using a coating system and a core tablet combination expected to have a narrow process operating space.
  
  
  RESULTS
  It was shown that the PyroButtons can provide a detailed and useful signature of the coating process. PyroButton data showed that the tablet-bed temperature was always lower than exhaust temperature and that the difference was a function of the operating conditions such as spray rate. Similarly, the tablet-bed humidity was found to always be higher than exhaust humidity. Some of the DOE batches showed coating defects (logo-bridging). It was shown that the relative humidity (RH), as measured by the freely-moving PyroButtons in the tablet-bed, correlated well with the logo-bridging events. A critical RH value (30%) was established, above which logo-bridging was observed for the selected formulation.
  
  
  CONCLUSIONS
  This study showed that PyroButtons can provide very meaningful micro-environmental data that can be correlated to coating defects, and can aid in establishing a process design space for a given coating and tablet formulation.
authors.affiliation: Drug Product Science and Technology, Bristol-Myers Squibb , New Brunswick, NJ , USA.
authors.forename: Preetanshu
authors.initials: P
authors.lastname: Pandey
authors.forename: Jiangning
authors.initials: J
authors.lastname: Ji
authors.forename: Ganeshkumar
authors.initials: G
authors.lastname: Subramanian
authors.forename: Shruti
authors.initials: S
authors.lastname: Gour
authors.forename: Dilbir S
authors.initials: DS
authors.lastname: Bindra
mesh_terms: D002626:Chemistry, Pharmaceutical / Q000295:instrumentation / Q000379:methods*; D004867:Equipment Design; D005079:Excipients / Q000737:chemistry*; D006813:Humidity; D013607:Tablets; D013696:Temperature; D013816:Thermodynamics
chemical_list: D005079:Excipients; D013607:Tablets