The use of extragranular disintegrants in multiple-unit tablet formulations: effect on compressibility, compactibility and disintegration

Multiple-unit tablets formed from mixtures of microcrystalline cellulose pellets and disintegrants (Ac-Di-Sol, Primojel or Kollidon CL) by compaction were investigated with the aim of controlling tablet tensile strength and disintegration time. The effects of pellet porosity, compaction pressure, and type and amount of disintegrant were studied. Primojel made the pellets less prone to deformation during compression, while the other two disintegrants had very minor effects on the compression behavior. Ac-Di-Sol and Primojel generally increased the tablet tensile strength, whereas the effect of Kollidon CL was dependent on the initial pellet porosity. Kollidon CL was found to significantly reduce the disintegration time, but the other two disintegrants had variable efficacy, and for the low-porosity pellets significantly increased the disintegration time. These results are interpreted as resulting from the interplay between the mechanical characteristics of the pellets and the mechanisms of action of the disintegrants.