The present invention is concerned with delivering a pharmaceutical
composition to a tissue target of a mammalian subject for treating brain
diseases or disorders. The process includes the steps of: (i) providing a
dispersion of the pharmaceutical composition as particles having an
average particle size of from about 150 nm to about 100 microns, and (ii)
administering the dispersion to the mammalian subject for delivery to the
tissue target of a portion of the pharmaceutical composition by cells
capable of reaching the tissue target. The dispersion of the
pharmaceutical composition as particles, for example, can be phagocytised
or adsorbed by the cells prior or subsequent to administration into the
mammalian subject. The dispersion of the pharmaceutical composition can
be administered to the central nervous system or the vascular system.
After administration, the loaded cells transport the pharmaceutical
composition as particles into the tissue target.