Parameters Azithromycin Sparfloxacin Cephalexin monohydrate λmax(nm) 595 620 600 Molar ratio (D:R) 2:1 2:1 2:1 Linear range (μg mL-1) 0-50 10-80 10-170 Slope 0.0178 0.0096 0.0007 Intercept 0.0418 -0.1028 -0.0080 Sandell’s sensitivity (μg cm-2) 0.0559 0.1034 1.3920 Correlation coefficient 0.9871 0.9967 0.9992 Stability constant (log K) 6.19 ± 0.04 5.00 ± 0.07 4.05 ± 0.05 Molar absorptivity (L mol-1 cm-1) 1.369×104 3.774×103 2.620×102 LODa(μg mL-1 ) 0.10 0.21 1.69 LOQb (μg mL-1 ) 0.35 0.71 5.63 %RSDc(at 10 μg mL-1) 0.55 0.33 3.06 ΔGod(kJ mol-1) -2.725×103 -2.393×103 -1.938×103

aLimit of detection bLimit of Quantitation cRelative standard deviation dFree energy change

Table 1: Qualitative and statistical parameters for proposed methods.