Micellar-Enhanced Spectrofluorimetric Method for Quantification of Diclofenac Potassium in Pure Form, in Pharmaceutical Preparations and Human Plasma

A rapid, simple and economical spectrofluorimetric method for the determination of diclofenac potassium in pure form, in pharmaceutical preparations and in human plasma has been developed. The method is based on the enhancement of the fluorescence signal of diclofenac potassium by the addition of sodium dodecyl sulphate in McIvaine buffer with a pH of 5. Different experimental conditions such as buffer type, pH, type and concentration of surfactants were investigated. The fluorescence intensity of the solution was recorded at 361 nm after excitation at 243 nm. The method shows linearity in the concentration range of 0.2 μg mL–1–10 μg mL–1 with a good correlation coefficient of 0.997. The relative standard deviation value was 3.62 (n = 7). The limit of detection and limit of quantification were calculated to be 2.84 × 10–3 μg mL–1 and 9.47 × 10–3 μg mL-1, respectively. The effect of excipients and co-administrated drugs was investigated and no interference was observed. The method was successfully applied for the determination of diclofenac potassium in pure form, in pharmaceutical products and in human plasma. The percentage recoveries obtained ranged from 100.25% to 102.16% for pure form and 97.50% to 102.00% for pharmaceutical products and from 98.50% to 101.67% for human plasma.

A Micellar-Enhanced Spectrofluorimetric Method for the Determination of Ciprofloxacin in Pure Form, Pharmaceutical Preparations and Biological Samples

A simple, fast and interference free spectrofluorimetric method was developed for the quantification of ciprofloxacin in its pure form, pharmaceutical preparations and in human plasma. The method is based on the enhancement of the weak fluorescence signal of drugs by the addition of sodium dodecyl sulphate (SDS) surfactant micelles in citrate buffer at pH 5.5. Different experimental parameters like buffers, surfactant type and concentration were investigated. The fluorescence intensity of ciprofloxacin was measured at 446 nm (emission) and at 328 nm (excitation). A linear relationship between concentration of ciprofloxacin and fluorescence intensity was found in the range of 0.04 μg/mL–6.0 μg/mL with a correlation coefficient of 0.9946. The limit of detection (LOD) and limit of quantification (LOQ) were calculated and found to be 3.87 × 10−5 and 1.29 × 10−4 μg/mL respectively. The effect of common excipients and co-administered drugs were also investigated and the method was found free of interferences. The method was successfully applied for the determination of ciprofloxacin in pharmaceutical preparations and human plasma with percentage recoveries of 97.08 % to 99.32 % and 95.00 % to 101.25 % respectively.