Flow Injection Spectrofluometry For Pharmaceutical Analysis And Its Application

As one of the important pharmaceutical analysis methods, the fluorescence analysis especially combined with flow injection technology, was developing fast in recent years and playing an important role on pharmaceutical analysis for its high sensitivity and selectivity. Part of phartmaceutical moleculars could have strong fluorescence after being oxidized although they have no or weak native fluorescene characteristics. In this paper, we have developed two new methods with flow injection on-line oxidizing fluorometry to study on the concentration determination of carbamazepine (CBZ) and chlorprothixene (CPX), carbamazepine-protein binding and dissolution profile of chlorprothixene.There are three chapters in this thesis.Chapter one: The Research of Flow Injection Florometry for Pharmaceutical Analysis1. The development of flow injection fluorometry for pharmaceutical analysisIn this part, the flow injection fluorometry, as one of the important pharmaceutical analysis methods, were summarized in detail according to the difference between their analysis principles in recent years, and its future developments were prospected.2. Flow injection fluorometry for the determination of carbamazepine in pharmaceuticals and plasmaA simple, sensitive and specific spectrofluorimetric method has been developed for the determination of CBZ. The method was based on lead dioxide solid-phase reactor flow injection on-line oxidizing CBZ into fluorescent product in medium of phosphoric acid. The product has green-yellow fluorescence at excitation wavelength of 355 nm and emission wavelength of 478 nm, and the fluorescence intensity could be enhanced in the presence of acetone. The reaction conditions and experimental conditions were studied and optimized. Under the optimum conditions, the fluorescence intensity was proportional to the concentration of CBZ in the range from 0.0005 to 4 μg ml-1. The detection limit was 5.7×10-11 g ml-1 (2.4×10-10 mol L-1) and the relative standard deviation was 1.4 % at the sampling rate of 45 h-1. The proposed method was applied to determination of CBZ in commercial tablets and the results agreed well with those obtained by the official method. Then, the method was further extended to determination of CBZ in spiked human plasma samples.3. Flow injection fluorometry for the determination of chlorprothixene in pharmaceutical formulationsA new flow injection spectrofluometry for the determination of CPX was developed based on lead dioxide solid-phase reactor flow injection on-line oxidizing CPX into fluorescent product with excitation wavelength of 393 nm and emission wavelength of 452 nm in medium of sulphuric acid, and the fluorescence intensity could be enhanced in the presence of acetone. The fluorescence intensity was proportional to the concentration of CPX in the range from 0.005 to 3 μg ml-1. The detection limit was 2.6×10-9 g ml-1 (8.2×10-9 mol L-1) and the relative standard deviation was 3.2 % at the sampling rate of 27 h-1. The proposed method was applied to determination of CPX in commercial tablets successfully and the results agreed well with those obtained by the official method.Chapter two: Analytical Methodology for Drug and Protein Binding Studies with Flow Injection Florometry1. Research review of drug-protein binding studyThe qualitative and quantitative aspects of several novel methods for drug and protein binding studies were reviewed, which include chromatography, capillary electrophoresis, mass spectrometry, nuclear magnetic resonance, frontal analysis and microdialysis as well as those of the traditional approaches such as equilibrium dialysis and ultrafilt ration reported in recent years. The advantages and limitations of these methods were discussed. Then the application of fluorescence analysis in drug-protein binding study was summerized.2. Flow injection on-line oxidizing fluorometry coupled to dialysis sampling for the study of carbamazepine-protein bindingThe mechanism of binding of CBZ with bovine serum albumin (BSA) has been investigated in vitro based on a new flow injection fluorometry coupled to the technique of dialysis sampling. The CBZ and BSA were mixed in different molar ratios in 0.050 mol L-1 phosphate buffer (containing 0.9% NaCl), pH 7.4, and incubated at 37 ± 0.5 ℃ in a water bath. The dialysis sampler was utilized to sample free CBZ from mixed solution with a relative dialytic efficiency of 7.6%. Then the CBZ in dialysis solution was injected into carrier and on-line oxidized by lead dioxide solid-phase reactor into fluorescent product with a maximum excitation wavelength of 355 nm and a maximum emission wavelength of 478 nm. The fluorescence intensity measured was linear proportional with the concentration of free CBZ in mixed solution over the range of 1×10-5 to 2×10-4 mol L-1 with the detection limit of 6×10-6 mol L-1. According to the...