Development and Validation of Micellar-Enhanced Spectrofluorimetric Method for Determination of Sulpiride in Pharmaceutical Formulations and Biological Samples

Sensitive and simple spectrofluorometric method has been developed and validated for the quantification of sulpiride in pure, commercial formulations, human plasma and urine in the presence of sodium dodecyl sulphate (SDS) surfactant micelle. The experimental parameters like buffer, surfactant type and volume were studied. A linear relationship was found between sulpiride concentration and fluorescence intensity in the range of 0.02 μg mL–1–7.0 μg mL–1 containing 0.2 M sodium dodecyl sulphate with λex 292 nm and λem 343 nm with a correlation coefficient of 0.9987. The limit of detection (LOD) and limit of quantification (LOQ) was found to be 1.9 × 10–2 μg mL–1 and 5.9 × 10–2 μg mL–1 respectively. The proposed method was successfully applied for the determination of sulphiride in pure and dosage form; the percentage recoveries agreed well with the label value. The effect of common excipients used as additive in pharmaceutical formulations was studied and no interferences was found. Similarly the effect of some common cations and compounds present in urine and plasma were also investigated and the method was found free of interferences. The method was further extended to the in-vitro determination of sulphiride in spiked human plasma and urine samples with percentage recoveries from 98.33%–99.75% and 95.67%–101.67% respectively. The results of the proposed method have been compared with the literature HPLC method and no significant difference was found between them.

Two charge-transfer complex spectrophotometric methods for the determination of sulpiride in pharmaceutical formulations

Two simple, rapid, accurate and sensitive spectrophotometric methods are described for the determination of sulpiride. They are based on charge transfer complexation between the drug as n-electron donor and p-chloranilic acid as π acceptor or iodine as σ-acceptor. These give highly coloured complexes with absorption maxima at 518 and 363, 294 nm, respectively. Beer’s law linear ranges were 13.7–341.4 and 1.7–20.5 µg mL−1 for the p-chloranilic acid and iodine methods. The methods were successfully applied to the determination of the drug in Dogmatil® Fort tablets and the results compared with the official method. The complex association constants and standard free energy changes were calculated using Benesi-Hildebrand plots.

Determination of indole-3-acetic acid in soil using excitation-emission matrix fluorescence with trilinear decomposition-based calibration methods

Indole-3-acetic acid (IAA) is a phytohormone of the auxin group and is capable of coordinating the overall processes of plant growth and development. IAA is active in the very low concentration range. Therefore, it is important to quantify IAA in the low concentration range in complex system. In this work, a new spectrofluorometric method for the direct determination of IAA in soil is proposed and discussed. It combines the fluorescence excitation-emission matrices (EEMs) with second-order calibration methods based on the alternating trilinear decomposition (ATLD) algorithm and the self-weighed alternating trilinear decomposition (SWATLD) algorithm. These methodologies fully exploit the second-order advantage of the three-way fluorescence data, allowing the analyte concentrations to be quantified even in the presence of unknown fluorescent interferents. IAA recoveries in soil were determined as 100.6 +/- 3.0 and 96.9 +/- 1.1% with ATLD and SWATLD, respectively. The limits of detection obtained were 17.6 and 4.6 ng mL(-1), and the limits of quantification were 52.9 and 13.9 ng mL(-1) with ATLD and SWATLD, respectively.