Composites of bead cellulose and hydrophilic solubilizers

Composites of regenerated bead cellulose (BC) and hydrophilic solubilizers were prepared by coprecipitation from common solvents. Infrared-drying was used for evaporation of organic solvents and freeze-drying for water. Infrared (IR)-dried BC coprecipitates with polyethylene glycols 400 or 6000 (PEG 400 and 6000) or Poloxamer were spherical, granulous and flowable up to a weight ratio of BC to solubilizer of 1:4. The solubilizers were completely incorporated into the pores of the BC and precipitated on the bead surface. Freeze-dried coprecipitates with solid solubilizers were received as loose voluminous powders of beads and leaf-shaped particles, those with PEG 400 as uniform spherical granules. Coprecipitates with PEG 6000 or Poloxamer showed strong crystallinity in contrast to the amorphous products with PEG 400. The melting points of the solubilizers in the coprecipitates were shifted to lower temperatures compared with the pure substances. The coprecipitates have the advantage over similar PEG or Poloxamer coprecipitates with drugs due to their good flow properties and favourable handling, and should be used as drug carriers for controlled release.