DEVELOPMENT AND VALIDATION OF A UV-SPECTROPHOTOMETRIC METHOD FOR THE DETERMINATION OF CEPHALEXIN MONOHYDRATE IN HUMAN PLASMA

Abstract

A simple, rapid and precise spectrophotometric method has been developed for the determination
of cephalexin monohydrate in plasma. The method was developed via scan of a standard
cephalexin solution at a concentration of 15 μg/ml and obtained a λmax of 261 nm and validated
in terms of linearity, accuracy and can be applied for routine estimation of cephalexin
monohydrate powder. This method utilized 40 % perchloric acid to precipitate plasma proteins
after spiking the plasma with different aliquots of cephalexin standard solution. The supernatant
of this solution was measured at 261 nm (λmax) after buffering with phosphate buffer (pH 4) and
volume adjustment with distilled water post-centrifugation to construct a 10 point calibration
curve. It was linear in the range of 5-150 μg/ml with a correlation coefficient of 0.9994 and the
percentage recovery was found to be 84-85.5 %.