A nanosuspension comprising (a) a pharmaceutical active ingredient or nutraceutical active ingredient having low solubility； (b) at least one alginate selected from the group consisting of (i) sodium alginate having a viscosity of 100 mPa·s or less in a 1% solution in water at 20° C. and (ii) potassium alginate； and (c) water. Also, a drug dosage form prepared from such a nanosuspension.
