The objective of this study is to develop controlled porosity osmotic pump tablet of Verapamil Hydrochloride, which is an antihypertensive candidate, using Polyethylene glycol (PEG) 400 as pore former in Cellulose acetate semipermeable membrane and Mannitol as a osmotic agent which release drug for extended period of time (24 h) and drug release of optimized formulation is independent of pH and agitation speed with zero order release.