A mechanistic investigation on the utilization of lactose as a protective agent for multi-unit pellet systems

Abstract

The effect of lactose particle size on the extent of pellet coat damage was investigated. The extent of pellet coat damage increased linearly with lactose median particle size. It was observed that coated pellets compressed with coarser lactose grades had larger and deeper surface indentations. The surfaces of the pellets compressed with coarser lactose grades were also found to be significantly rougher. Micronized lactose was capable of protecting pellet coats from damage brought about by the presence of coarser lactose particles. The findings suggested a protective effect that micronized lactose conferred to pellet coats was not only through dimensional delimitations but also by higher interparticulate friction and longer particle rearrangement phase. As a result, the pellet volume fraction in the system was reduced. The extent of pellet coat damage was found to escalate when the pellet volume fraction in such system increased beyond a critical value of 0.39.

• Coating
• compression
• lactose
• MUPS
• particle size
• pellets

Declaration of interest

The authors report no conflicts of interest. The authors alone are responsible for the content and writing of this article.

The authors would like to thank funding support for this study from GEA-NUS PPRL (N-148-000-008-001) and SERC Grant No. 102 169 0049 (R-148-000-157-305). Ms W. C. Chin was a recipient of the National University of Singapore Graduate Research Scholarship.