CONTEMPORARY ADVANCEMENTS IN DOWNSCALING OF ANALYTICAL SYSTEMS HAVE ADVANTAGEOUSLY FOSTERED DEVELOPMENT, AUTOMATION, AND MINIATURIZATION OF A VARIETY OF SAMPLE PREPARATION TECHNIQUES. DOWNSCALED SAMPLE PREPARATION TECHNIQUES PERMIT USAGE OF MICROLITER-VOLUMES OF SAMPLE SOLUTION, Extraction SOLVENT AND ACCEPTOR SOLVENT TO REACH ENVIRONMENTALLY FRIENDLY TECHNIQUES. DOWNSCALING OF ELECTROMEMBRANE Extraction TO MINIATURIZED DEVICES REPRESENT AN IMPORTANT DIRECTION IN THE FIELD OF ANALYTICAL CHEMISTRY. IN THE PRESENTWORK, A DOWN-SCALED CONSECUTIVE ON CHIP ELECTROMEMBRANE Extraction COUPLED WITH HIGH PERFORMANCE LIQUID CHROMATOGRAPHY WAS INTRODUCED FOR SIMULTANEOUS ANALYSIS OF ACIDIC AND BASIC DRUGS SUCH AS BETAXOLOL, DICLOFENAC AND MEFENAMIC ACID AS MODEL ANALYTES. IN PROPOSED SYSTEM, A SYRINGE PUMP INTO A DONOR CHANNEL IN A POLY (METHYL METHACRYLATE) CHIP INTRODUCED THE SAMPLE SOLUTION. THIS DONOR CHANNEL WAS IN DIRECT CONTACT WITH THE SLM, WHICH WAS COMPRISED OF A WATER IMMISCIBLE ORGANIC SOLVENT IMMOBILIZED IN THE PORES OF A FLAT SHEET OF POROUS POLYPROPYLENE. AN ACCEPTOR SOLUTION WAS LOCATED ON THE OTHER SIDE OF THE SLM. BY APPLYING ELECTRICAL POTENTIAL, MODEL DRUGS WERE EXTRACTED FROM THE SAMPLE SOLUTION, THROUGH THE SLM, AND INTO THE ACCEPTOR SOLUTION. EFFECTIVE PARAMETERS ON Extraction OF THE MODEL ANALYTES WERE OPTIMIZED USING ONE VARIABLE AT A TIME METHOD. UNDER THE OPTIMIZED CONDITIONS, THE NEW SETUP OFFERED A GOOD LINEARITY IN THE RANGE OF 20.0–500 MG L-1 WITH COEFFICIENT OF DETERMINATION (R2) HIGHER THAN 0.9982. THE RELATIVE STANDARD DEVIATION (RSD %) AND LOD VALUES WERE LESS THAN 7.1% BASED ON FOUR REPLICATE MEASUREMENTS AND 5.0 MG L-1 FOR THE MODEL ANALYTES, RESPECTIVELY. THE PRECONCENTRATION FACTORS HIGHER THAN 15.3-FOLD WERE OBTAINED. FINALLY, THIS METHOD WAS APPLIED FOR DETERMINATION OF THE MODEL ANALYTES IN REAL SAMPLES.