Abstract
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.
Extractive spectrophotometric determination of five selected drugs by ion-pair complex formation with bromothymol blue in pure form and pharmaceutical preparations