Abstract: A high—performance liquid Chromatographic method was developed to determine pilocarpine and its degradation products, isopilocarpine and pilocarpine acid in ophthalmic films. An ion—exchange resin ( Fartisil-lOSCX ) column was employed with 0.3 M phosphate buffer ( pH 6 ) containing 5% isopropanol as mobile phase. The influence of ionic concentration and acidity on column-performance was also investigated. The average recovery of five samples was found to be 100.3±0.6%.