The aim of this study was to develop and evaluate an extended-release (ER) push-pull osmotic pump (PPOP) tablet for phencynonate HCl (PCN), which could release the drug at zero-order profile for a duration of 24 h. The core tablets were designed as bi-layered, primarily composed of sodium chloride and polyethylene oxide (PEO). The central composite design (CCD) within a response surface methodology (RSM) was used to optimize the formulation. An optimized PCN-PPOP tablet formulation was achieved with the following values for key factors: 10 mg NaCl, 70 mg PEO, and 13.56% coating membrane weight gain. It revealed that this formulation could release PCN