An apparatus for disintegration (or mixing) of a solid in a receptacle containing liquid, has a control unit and an ultrasound transducer generating ultrasonic energy under control of the control unit. An annular coupling element in communication with the ultrasound transducer is adapted to receive the receptacle. Ultrasonic energy is transferred to the receptacle contents through the annular coupling element. In use, the ultrasonic energy transferred to the receptacle contents causes disintegration of the solid into the liquid. A method for disintegration of a solid in a receptacle is also described.