A top coating strategy with highly bonding polymers to enable direct tableting of multiple unit pellet system (MUPS)

Multiple unit pellet system(s), MUPS, is one of the most commonly used means for achieving modified drug release through oral administration. MUPS is usually delivered as capsules that contain drug bearing beads coated with a release modulating functional layer. While the routine manufacture of tablets of MUPS by direct compression is highly desired, it is faced with the problem of poor tableting properties or altered drug release behavior due to the rupture of the functional coating layer. The use of a significant amount of cushion material alleviates these problems, but is also challenged with the problem of segregation and reduced drug loading. We hypothesize that top-coating the beads with a layer of highly bonding polymer can enable direct tableting of beads without compromising the functional coating layer and avoid segregation problem. Using functionally coated pyridoxine and caffeine beads, we confirmed that top coating with Polyvinylpyrrolidone sufficiently plasticized with water can enable the preparation of strong tablets at even low compaction pressures. Drug release profiles of tablets are comparable to those of uncompressed beads, indicating negligible amount of damage, if any, to the functional coating layer. In conclusion, it has been demonstrated that top polymer coating may provide a promising universally applicable strategy to realize the goal of delivering MUPS in the form of tablet.