Synthesis of carboxymethyl cellulose (CMC) is carried out by using 32 factorial designs by using Design Expert software. The optimized conditions for CMC production with Design Expert software predicted the maximum viscosity of 3422.84 cP, degree of substitution of 0.386 and yield of 76.03% at NaOH concentration of 30% and Chloroacetic acid amount of 20 g. After optimization reaction condition was carried out experimentally obtained viscosity was 3421cP, degree of substitution was 0.38 and yield was 76%. Optimized Carboxymethyl cellulose was studied for qualitative test, physicochemical characterization. Instrumental analysis was performed for both cellulose and carboxymethyl cellulose from Spinacia oleracea. Instrumental analysis to confirmed effect after conversion of cellulose into carboxymethyl cellulose by carboxymethylation. In which cellulose and carboxymethyl cellulose were analyzed by FTIR, SEM, XRD, TGA and DSC. Application of carboxymethyl cellulose in pharmaceutical dosage form was carried out in which prepared carboxymethyl cellulose was compared to marketed CMC.