A free-flowing binder-disintegrant powder material consisting essentially of a precompacted-starch powder, especially adapted for use in direct compression tabletting machines to produce non-friable tablets having excellent disintegration properties. This precompacted-starch powder is also useful as a free-flowing filler for blending with dry powder ingredients in dry-dosage capsules. The precompacted-starch powder is obtained by subjecting an ungelatinized granular starch to physical compaction without supplementary thermal energy, but with sufficient mechanical energy input to obtain a precompacted-starch having birefringent granules and non-birefringent fragments of granules and some aggregates of granules and fragments, and then dried to a moisture content of 9-16% total weight basis. After precompacting, the starch is pulverized to form a free-flowing powder having a loose bulk density of 0.5 to about 0.7 grams per milliliter. The precompacted-starch powder is essentially free of +40 mesh particles, at least 90% of the particles are -80 mesh, at least about 10% is +270 mesh, and from about 30% to 90% is -270 mesh size on a total weight basis (U.S. Standard Sieve Series, A.S.T.M. Specifications).
Cold water solubility of the precompacted-starch powder is in the range of from 4% to about 40% by weight, preferably about 10% to 20% by weight, and this powder is capable of being formed into a hard, non-friable tablet in combination with other active ingredients in a direct compression tabletting machine, the precompacted-starch powder being dually functional as both a binder and disintegrant. The resulting tablet has a hardness index of at least about 4 kilograms, preferably at least 8 kilograms, a friability loss of less than 1% by weight, a swelling power of 2.5 to about 12, preferably at least 8, and is capable of effectively disintegrating when placed in water.