Injectable microspheres are obtained from double bond functionalized polyhydric alcohol ester by a method comprising dissolving the double bond functionalized esters in a hydrophobic organic solvent, forming an aqueous solution of stabilizer, forming an oil in water emulsion where the solution of stabilizer constitutes the continuous phase and the solution of ester constitutes the disperse phase and evaporating the organic solvent or from block copolymer of PGCLM and methoxy poly(ethylene glycol).