A process of preparing a stable pharmaceutical composition comprising amorphous of Mirabegron comprising the steps of: Dissolving Mirabegron in a solvent(s) Stirring the mixture until the Mirabegron get completely dissolved or dispersed Evaporating the solution by spraying on the drymix bed consisting of polymer and diluent at a temperature of 1 ooc to 80°C in a fluid bed processor and using the blend and formulating the desired formulation of tablets, capsules and dry mix using formulation techniques 20
