The present invention relates to sustained release solid pharmaceutical composition comprising anti-hypertensives, in particular, Metoprolol succinate or pharmaceutically acceptable derivatives thereof and a process for preparing such a formulation. The present invention provides an extended release composition comprising Metoprolol succinate or its pharmaceutically acceptable derivatives along with one more suitable hydrophilic polymer in combination with hydrophobic polymer, wherein the composition releases the drug over extended period of time. The present invention also describes use of suitable release retardant in coating comprised of aqueous pore former which help to modulate the drug release in controlled manner over period of time.
