Abstract: A method enables evaluation of the purity of an active pharmaceutical ingredient contained in a complex, and a method of producing a complex in which the purity of the active pharmaceutical ingredient is not less than 95.0%. The purity evaluation method includes: a reaction step of reacting a complex with a nitrogen-containing nucleophile such as hydroxylamine in the presence of a protonic acid in a polar solvent; and an evaluation step of evaluating the purity of the reaction mixture obtained by the reaction step, by high-performance liquid chromatography. The method of producing a complex includes a reaction step of reacting an anthracycline drug with an N-(2-hydroxypropyl)methacrylamide polymer in the presence of a protonic acid in a polar solvent at not more than 10° C., to obtain the complex.

Abstract: Modified graphite particles are described, which have an almost circular and tabular shape, an average particle size Ap of 12 to 18 &mgr;m, a BET specific surface area Ss of 4 to 6 m2/g, and a BET specific surface area to average particle size ratio, Ss/Ap, of 0.35 or less, and which are obtained by treating tabular particles of lumpy or flaky graphite to break or slightly fold the periphery of the tabular particles to increase the degree of circularity. A battery having the modified graphite particles as an anode active material is also described.

Abstract: Modified graphite particles are described, which have an almost circular and tabular shape, an average particle size Ap of 12 to 18 &mgr;m, a BET specific surface area Ss of 4 to 6 m2/g, and a BET specific surface area to average particle size ratio, Ss/Ap, of 0.35 or less, and which are obtained by treating tabular particles of lumpy or flaky graphite to break or slightly fold the periphery of said tabular particles to increase the degree of circularity. A battery having the modified graphite particles as an anode active material is also described.