[Spectrophotometric method for aminoglycoside concentration measurement in blood plasma].

The aim of the research was to develop a simple, available and rapid spectrophotometric method for measuring aminoglycoside concentration in blood plasma and to evaluate the antibiotic efficacy and susceptibility. The method is based on the ability of aminoglycosides, in particular amikacin, to change the color of Fast Blue B Salt Dye (SIGMA-ALDRICH). An antibiotic at various concentrations and the dye were added to blood plasma. The resulting mixture was filtered to separate the insoluble residue. After that the optical density of the filtrate were measured spectrophotometrically against the control specimen with no antibiotic at the wavelength of 450 nm. It was demonstrated that an increase in the plasma antibiotic concentration led to a directly proportional increase of the antibiotic solution extinction. This is a simple, precise and rapid method.