Abstract
Over the last decade, the conical mill has emerged as a potential piece of equipment to use for continuous dry coating pharmaceutical powders. In this work, silicon dioxide was used as a guest particle on two excipients, fast flow lactose (FFL) and grade PH200 microcrystalline cellulose (MCC), for dry coating by a conical mill with a modified screen that permitted batch and continuous mode operation. Samples were pre-processed in a V-blender. SEM images, particle size distribution, and EDS mapping were used to characterise the treated powders. Pre-processed samples showed some discrete coating of the host particle. After batch processing, the samples were covered with a complete coating. When processed at high impeller speed, coating of FFL was a mix of A200P and FFL fines generated by attrition. Continuous mode processed samples, which had a lower processing time, were coated discretely and showed a better coating than the pre-processed samples. Increasing guest/host mass ratio with FFL host particle had a positive impact on the quality of the coating. These results help to build the case that the processing time of the conical mill is a key parameter to the success of the conical mill as dry coating equipment in the pharmaceutical industry.
Highlights
Dry coating is a method that relies on the use of guest particles with specific properties to cover the surface of the host particle
Various results presented will help to validate the efficacy of the conical mill for dry coating pharmaceutical excipients
The literature shows that the conical mill leads to dry coating of pharmaceutical powders as a continuous mode equipment [3,4,13,14,18–25]
Summary
Dry coating is a method that relies on the use of guest particles with specific properties to cover the surface of the host particle. The potential it has to modify flow and surface properties of APIs and excipients is the reason why interest has grown in the pharmaceutical industry for this method since the early 2000s [1,2]. It can be used to create a process where dry coated powders are directly compressible [3–5]. This can help to save costs related to the drying step following wet granulation as well as to treat heat and/or moisture sensitive drugs without loosing compressibility, a disadvantage of dry granulation [6]. The initiatives reported by some pharmaceutical companies offer several advantages regarding the dry coating process: (a) more compact equipment size and layouts for longer periods of time; (b) reduced space and utility costs; (c) reduction in overall operating costs; (d) more consistent product quality with tighter specifications [10]
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
