ABSTRACT

In present study, three new spectrophotometric methods, original UV spectrophotometry, first and second order derivative UV spectrophotometry, were developed for the determination of amoxicillin in pharmaceutical preparations. In original UV spectrophotometry, absorbances were measured at 247.0 nm in the zero order UV spectra of the solution of amoxixillin in 0.1N NaOH in the range of 220 - 350 nm. In first derivative UV spectrophotometry, dA/d∠ values were measured at 255.8 nm in the first derivative UV spectra of the solution of amoxicillin in 0.1N NaOH in the range of 220 - 320 nm (∆∠= 2 nm). In second derivative UV spectrophotometry d²A/d∠² values were measured at 249.2 nm in the second derivative UV spectra of the solution of amoxicillin in 0.1N NaOH in the range of 220 - 320 nm (∆∠= 4 nm). Linearity range was found as 3.2 - 48.0 ug/mL in all three methods. Mean recoveries and the relative standard deviations of the methods were found as 99.67 % and 1.20 % in original UV spectrophotometry at 247.0 nm, 99.04 % and 1.76 % in first derivative UV spectrophotometry at 255.8 nm and, 99.43 % and 2.34 % in second derivative UV spectrophotometry at 249.2 nm respectively. Three spectrophotometric methods developed were successfully applied to 8 tablets, 2 oral suspensions and 1 lyophilized powder formulation commercially available in Turkish drug market. All the results were compared statistically with those obtained by using the methods indicated in USO XXIII.