An eco-friendly first and second derivative synchronous spectrofluorimetry for quantification of florfenicol in presence of its different degradation products. Application to kinetic stability study.

Two rapid, simple, sensitive and selective derivative spectrofluorimetric methods (first and second derivative synchronous spectrofluorimetric (FDSFS and SDSFS) procedures) have been developed for the analysis of florfenicol in the presence of its various degradation products. FDSFS was applied to assay the drug in the presence of its alkaline, oxidative and photolytic degradation products while SDSFS was used to quantify it in the presence of its acidic degradation product. These methods permitted quantification of florfenicol at corresponding λ Em of 288, 287, 279 and 284 nm without interferences from any of its degradation products. Full validation procedures were applied to the suggested method according to International Conference of Harmonization guidelines. Moreover, different degradation kinetic parameters were calculated such as half-life (t 1/2), degradation rate constant (K) and activation energy (E a). Using the analytical eco-scale, green analytical procedure index and analytical greenness metric approach AGREE as greenness assessment tools, the proposed method was found to be environmentally friendly.

Analysis of clozapine in its tablets using two novel spectrophotometric reactions targeting its tertiary amino group.

Two simple spectrophotometric methodologies have been proposed and validated for the measurement of an atypical antipsychotic drug Clozapine (CLZ). Method A depends on interaction of CLZ with N-bromosuccinimide(NBS) resulting in formation of a yellowish orange colored product, measured at 320 nm. The linearity range was 5.0-70.0 µg/mL. Method B depends on condensation of the same drug with acetic acid mixed anhydride reagent producing a purple colored product, measured at 319 nm. The linearity range was 8.0-24.0 µg/mL. All parameters affecting the reaction condition (volume of both reagent, temperature, time and the different diluting solvents) were optimized. Both methods were successfully applied to assay CLZ in its pure form and tablets giving mean percentage recoveries of (98.87 ± 1.8 and 100 ± 1.7) for method A, and corresponding values of (98.6 ± 0.96 and 99.5 ± 1) for method B. Besides, the study of reactions stoichiometry was performed and the reaction mechanisms were proposed.