Fabrication and characterization of extruded and spheronized beads containing Carbopol(R) 974P, NF resin

Carbopol(R) 974P, NF resin is a synthetic, cross-linked, acrylic acid polymer. It becomes tacky when wetted, which introduces handling difficulties with techniques involving water or other fluid. To reduce tack, the water for welting was replaced by an aqueous solution of a strong electrolyte. The effect of the concentration and type of electrolyte on the adhesive force of the wet mass was measured. A correlation was found between the charge density of the cation and the minimum salt concentration necessary to eliminate problems associated with tack. Beads containing chlorpheniramine maleate, Carbopol(R), Avicel PH101, and electrolytes were successfully manufactured by extrusion-spheronization. The Carbopol(R) concentration, as well as the pH and ionic strength of the dissolution medium and the rotation speed of the paddles, can modify drug release.