Effect of polyvinylpyrrolidone solutions containing dissolved drug on characteristics of lactose fluidized bed granules

Abstract

The use of different grades of polyvinylpyrrolidone (PVP) in solutions containing dissolved drug with lactose as feed material for fluidized bed granulation were studied. The action of PVP K25, K29-32 and K90 influenced the characteristics, such as mass median diameter, span, wt.% < 250 μm and crushing strength of the granules. This was associated with the volume and concentration of PVP solution used. Increasing the volume of binder solution subjected the feed material to a prolonged granulation process and increased the total quantum of binding effect. The feed material responded through the formation of larger granules. The span and wt.% < 250 μm decreased. This was attributed to secondary agglomeration, layering effect being the prominent process. The crushing strength values were higher for larger volume and higher concentration of binder used. This is due to more binder being deposited on the granules, which when dried would manifest as solid bonds giving tenacity to the structural framework of the granule. The viscosities of PVP K25 and K29-32 solutions were similar to corresponding solutions with dissolved drug. As such, characteristics of granules with PVP K25 were similar to those with PVP K29-32. In the case of PVP K90, this binder was able to confer strong bonds to the granules and this enabled them to better withstand the effects of attritive forces generated during granulation. The opportunity for size growth was greatly enhanced. As a result, the mass median diameter was higher, the span value and percentage weight < 250 μm relatively lower with respect to corresponding batches produced with PVP K25 and PVP K29-32.