A ready to use stable sustained release oral liquid suspension dosage form of pharmaceutical active ingredients which is easy to administer and particularly beneficial for the pediatric and geriatric patients. The suspension dosage form comprises sustained release pellets comprising inert pellets surrounded by seal coating drug layer comprising pharmaceutically active ingredient with one or more pharmaceutically acceptable excipients surrounding said seal coated inert pellets and coating layer comprising rate controlling polymer surrounding said drug layer such that the sustained release pellets are suspended with suitable suspending agent in addition to other pharmaceutically acceptable excipients in a suspending media at a suitable pH. A process for preparation of the suspension dosage form is also provided.
