Provided is a composition comprising (i) a nano- or microparticle formulation of a therapeutically active agent which is suspended in a liquid phase, and (ii) at least one cryoprotective additive selected from C3-C5 alkanes substituted by one or two hydroxy groups which stabilizes the particle formulation. Further aspects relate to a solid composition which can be obtained by freezing the stabilized composition, and to processes for the preparation of the compositions in accordance with the invention.
