Methods and compositions for providing long term pain relief in, for example,surgery recovery, including injectinga composition comprising a plurality of microparticles having different sizesand at least one local anesthetic loaded into themi-croparticles at different loading levels. Extended prolonged blockage ofnerve action in sheep testing was confirmed. Some of themicroparticles comprise a high loading of local anesthetic. Testing in sheepshowed nerve blockage for at least six days.
