Structure and dry binding activity of different polymers, including Kollidon((R)) VA 64

The dry binding activity of copolyvidone (Kollidon(R) VA 64), povidone (Kol lidon(R) 30), microcrystalline cellulose (Avicel(R) PH-101), hydroxypropylm ethylcellulose (HPMC) 2910 (Pharmacoat(R) 606), and maltodextrin (Maldex(R) 18) was investigated using a variety of formulations and methods. The effe ct of the dry binders in direct tableting and compaction was studied using a dicalcium phosphate formulation (water-insoluble ingredients) and a vitam in C formulation (water-soluble ingredients) applying three compression for ces. The binder content was varied between 5% and 15% in both formulations, and the tablet properties were determined. All the tablets showed an impro vement in mechanical properties (hardness, friability) with increasing dry binder concentration, with Kollidon VA 64 showing by far the greatest bindi ng efficacy. A significant influence (prolongation) on drug release was obs erved only with HPMC 2910. The drying binding properties were analyzed for correlations with various powder and material properties. Especially, parti cle size, surface/surface structure, and plasticity were found to influence binding activity. The ideal dry binder should have small particles, high p lasticity, and a large surface area.