The present invention relates to a composition suitable for administration to a subject, the composition comprising pharmacologically acceptable particulate material dispersed throughout a pharmacologically acceptable liquid carrier, the particulate material being maintained in the dispersed state by a steric stabilizer, wherein the steric stabilizer is a polymeric material comprising a steric stabilizing polymeric segment and an anchoring polymeric segment, one or both of which are derived from one or more ethylenically unsaturated monomers that have been polymerized by a living polymerization technique, wherein the steric stabilizing polymeric segment is different from the anchoring polymeric segment, and wherein the anchoring polymeric segment has an affinity toward the surface of the particulate material and secures the stabilizer to the particulate material.