Use of kappa-carrageenan as alternative pelletisation aid to microcrystalline cellulose in extrusion/spheronisation. I. Influence of type and fraction of filler.

Microcrystalline cellulose (MCC) is commonly used as an excipient in extrusion/spheronisation process. However, MCC has several disadvantages as lack of disintegration and drug adsorption. Therefore, kappa-carrageenan was investigated to substitute MCC in pelletising processes. Formulations with 20% of pelletisation aid (kappa-carrageenan or MCC) and acetaminophen as a model drug have been produced. Different fillers (lactose, mannitol, maize starch and dicalciumphosphate dihydrate) at fractions of 0, 20, 40 and 80% were evaluated and the properties of the resulted pellets were determined (e.g. yield, aspect ratio, mean Feret diameter, 10% interval fraction, tensile strength and release profile). kappa-Carrageenan has proven to be a suitable substitute as pellets with sufficient quality were produced. The pellet batches of different formulations were characterised by high yield, spherical pellet shape and narrow pellet size distribution. The distinguished behaviour between kappa-carrageenan and MCC pellets was the lower tensile strength and the faster release of kappa-carrageenan pellets. For the various types and fractions of fillers only minor effects to the pelletisation process and pellet properties were noticed. From the practical view these effects are neglectable indicating a robust formulation and process.