Method and device of making a suspension of microparticles homogeneously distributed in an aqueous liquid carrier

A method of mixing a liquid composition, wherein said liquid composition comprises microparticles dispersed in a liquid carrier and wherein said liquid composition is contained in a syringe having a longitudinal horizontal axis (X-X), the method comprising:

• a first premixing step in which the syringe is oscillated about said longitudinal horizontal axis clockwise and counter-clockwise from a first reference point (B), through a first angle of rotation (δ) for a first period of time and at a first angular velocity;
• a second premixing step, performed in sequence to the first premixing step, in which the syringe is oscillated about said longitudinal horizontal axis clockwise and counter-clockwise from a second reference point (C;
• D), through a second angle of rotation (γ) for a second period of time and at a second angular velocity;
• and
• wherein said first angle of rotation is smaller than said second angle of rotation, and said first period of time is shorter than said second period of time.