A kinetic approach for determination of cefadroxil in pharmaceuticals by alkaline hydrolysis

A new, simple, and sensitive kinetic spectrophotometric method is described for analysis of cefadroxil by measurement of its absorbance at 470 nm after hydrolysis with NaOH at 80 degrees C, Studies of the method's precision and accuracy gave a standard deviation of 0.44 mu g/mL and a relative standard deviation of 1.93%. The method determines cefadroxil over the concentration range 10-100 mu g/mL. Calculated activation parameters were 12.42, 25.54, 26.25, and 69.00 Kcal/mole for Delta E#, Delta G(#), Delta H-#, and Delta S-#, respectively. Cefadroxil concentrations can be determined from the regression line equation y = 0.627 x -8.14 x 10(5), with a correlation coefficient of <1.0000. The method was validated by assay of cefadroxil in commercial capsules and tablets. Recoveries of common excipients were 99.6, 100.00, 99.2, 99.6, and 100.4% for lactose, glucose, starch, sucrose, and fructose, respectively. Results were compared with those of a reference method. Calculated t and F values indicate no significant difference between the 2 methods. The degradation products of cefadroxil do not affect determination of cefadroxil.