The present invention relates to pharmaceutical formulations suitable fortargeting particular tissue and/or organ(s)with a formulated active ingredient, for example when administered upstream ofthe target organ or tissue, and to use of the samein treatment, methods of treatment administering the same and methods ofpreparing the formulations. The pharmaceutical formulationsof the invention are for parenteral administration to a target tissue andcomprise particles containing an active ingredient,and a biodegradable excipient, wherein 90% or more of the particles have adiameter of between 10 and 20 microns and the formulationis substantially free of particles with a diameter greater than 50 microns andless than 5 microns, such that where the formulationis administered upstream of the target tissue the ability of the active topass through the target tissue and pass into systemiccirculation is restricted.
