Objective: The present manuscript describes about simultaneous multiple response optimizations using the Derringer's desirability function for the estimation of cefixime and ofloxacin in bulk and pharmaceutical dosage form by using HPTLC method.Methods: Central composite design (CCD) was used for the optimization of chromatographic conditions in HPTLC. The independent variables used for the optimization were n-butanol content in the mobile phase, chamber saturation time and distance travel. HPTLC separation was performed on aluminum plates pre-coated with silica gel 60 F 254 as the stationary phase using n-butanol: Ammonia: water (8:3:1 % v/v/v) as the mobile phase. Quantification was achieved by densitometric analysis of cefixime and ofloxacin over the concentration range of 20-120ng/band at 297 nm.Results: The method gave compact and well-resolved band at Rf of 0.43±0.02 and 0.73±0.02 respectively for cefixime trihydrate and ofloxacin hydrochloride. The linear regression analysis for the calibration plots showed r2 = 0.99985 and r2 = 0.9989 for cefixime and ofloxacin respectively. The optimized method complies validation parameters like precision, accuracy, robustness, specificity, limit of detection and limit of quantification as per ICH guidelines.Conclusion: The mobile phase composition, chamber saturation time and solvent front factors are evaluated in the robustness test. The selected factors were found to have a significant effect on the Rf value of both drugs. The optimized method contains 7 ml of n-butanol, 75 mm solvent front and 33 min of saturation time was used. So the optimization process reduces the solvent usage and increases separation sensitivity for both drugs. The results indicate the CCD method is suitable for the routine quality control testing of marketed tablet formulation and bulk drugs.Keywords: Cefixime, Ofloxacin, Central Composite Design (CCD), High-performance thin layer chromatography (HPTLC), Validation, Optimizatio
