NOVELTY - An amorphous mirabegron (A1), is new.    USE - For the treatment of a disease associated with overactive bladder (claimed), where the disease includes urinary frequency, urinary incontinence, or urgency associated with overactive bladder.    ADVANTAGE - The amorphous mirabegron has chemical purity of greater than 99.9%. The process of making mirabegron is simple, reproducible, environment friendly, cost effective, and industrially feasible.    DETAILED DESCRIPTION - INDEPENDENT CLAIMS are included for the followings:    (1) preparing the amorphous mirabegron (A1);    (2) an amorphous solid dispersion of mirabegron together with at least one carrier;    (3) preparing the amorphous solid dispersion of mirabegron, involving providing a solution of mirabegron in combination with at least one carrier in a solvent or mixture of solvents, removing the solvent from the solution or suspension obtained in previous step or combining the solution obtained in pervious step with an anti-solvent, and isolating solid dispersion of amorphous mirabegron together with at least one carrier;    (4) a solid pharmaceutical formulation (C1) comprising the amorphous mirabegron (I) or solid dispersion of amorphous mirabegron;    (5) preparation of alpha -form crystal of mirabegron, either involving method (M1): dissolving mirabegron in a solvent selected from methanol, ethanol, tetrahydrofuran, ethyl acetate, and/or toluene to provide a solution, cooling the solution obtained in previous step, and isolating alpha -form crystal of mirabegron; or method (M2): providing a solution of mirabegron in a solvent selected from tetrahydrofuran, methanol, ethanol, acetone, acetonitrile, 1,4-dioxane, methyl isobutyl ketone, and/or chlorobenzene, adding an anti-solvent to the obtained solution, selected from cyclohexane, methylcyclohexane, n-heptane, diisopropyl ether, methyl tertiary butyl ether, toluene, water, provided that when methanol is used as a solvent then anti-solvent is other than water, and isolating alpha -form crystal of mirabegron;    (6) a solid pharmaceutical formulation (C2) comprising alpha -form crystal of mirabegron obtained in the method (M1) and (M2) and at least one carrier.