An osmotic therapeutic system for delivering a beneficial drug is disclosed. The system comprises a drug delivery module which module comprises a rate controlling laminated wall surrounding a reservoir and has a portal for delivering drug from the system. The laminated wall comprises a semipermeable lamina in laminar arrangement with a microporous lamina to provide a wall that is permeable to an external fluid, impermeable to drug and maintains its integrity during the delivery of drug. The reservoir contains a drug, or a mixture of drug and solute which drug or solute is soluble in the fluid and exhibits an osmotic pressure gradient across the wall against the fluid. In operation, drug is released from the system by fluid being imbibed through the wall into the reservoir at a rate determined by the permeability of the wall and the osmotic pressure gradient across the wall thereby producing a solution of drug, or a solution of solute containing drug which solution is released through the portal at a controlled rate over a prolonged period of time.