Rheumatoid arthritis, or RA, is an autoimmune and inflammatory disease, which means that your immune system attacks healthy cells in your body by mistake, causing inflammation (painful swelling) in the affected parts of the body. RA mainly attacks the joints, usually many joints at once. A complexation, derivatization, extraction, evaporation and sensitive-free direct a new, simple, precise, accurate, reproducible, and efficient UV spectrophotometric method is developed and validated for the simultaneous estimation of ternary mixture of rabeprazole, (MET) aceclofenac (SXG) and paracetamol (DGF) in both their bulk form and combined in tablet dosage form recently approved by FDA in 2019 to be used for treatment of Type 2 diabetes mellitus by simultaneous equation method. The solutions of standard and sample were prepared in methanol: water (80:20 v/v). The 𝜆max for MET, SXG, and DGF were 232.0, 212.0 and 272.0nm, respectively. Calibration curves are linear in the concentration ranges 10-50𝜇g/ml for MET, 1-5𝜇g/ml for SXG and 5-25𝜇g/ml for DGF, respectively. Results of analysis of simultaneous equation method were analyzed and validated for various parameters according to ICH guidelines.