Binding study of drug with bovine serum album using a combined technique of microdialysis with flow-injection chemiluminescent detection.

Microdialysis coupled with flow-injection chemiluminescence (FI-CL) has been developed to determine the binding parameters of a drug binding to protein by using antibiotic tetracycline hydrochloride binding to bovine serum albumin as a model system. The drug and protein were mixed in different molar ratios in 0.067 M phosphate buffer, pH 7.4, and incubated at 37 degrees C in a water bath. The microdialysis probe was utilized to sample the mixed solution at a perfusion rate of 5 microL/min. The concentration of unbound tetracycline hydrochloride in the microdialysate was determined by FIA-CL. In vitro recovery of tetracycline hydrochloride under experimental conditions was 30.0%. The data obtained by the present microdialysis-FI-CL system was analyzed using the Scatchard analysis and Klotz plot. The results show that the Scatchard plot and Klotz plot are linear with good correlation coefficient, indicating a good agreement of the experimental data and to the theoretical equation. The FIA chemiluminescence system combined with microdialysis developed in this work demonstrated its use for determination of interaction between drug and protein by using relatively simple instrument.