Validation of new spectrophotometric methods for quantitative determination of 7-ADCA in pharmaceutical formulations.

Three simple, sensitive and accurate methods are described for the determination of 7-Amino deacetoxy cephalosporanic acid (7-ADCA) in bulk drug and in formulations. Methods Ma to Mc are based on Redox / complex formation reaction between 7-ADCA and ammonium Molybdate and sulphuric acid (AM/H2SO4) (Ma), Ferric chloride/ Ortho Phenonthraline (Fe+3/o-Phen)(Mb) and FeCl3/potassium Ferricyanide (Fe+3/K3Fe(CN)6) (Mc) solutions. The chromogen being extractable with chloroform could be measured quantitatively at 625 (Ma), 510 (Mb) and 740 nm (Mc). All variables were studied to optimize the reaction conditions. Regression analysis of Beer's Law plot showed good correlation in the concentration ranges 10-60 for Ma, 1.25-7.5 for Mb and 2.5-15 mg/ml for Mc. The calculated molar absorptivity values are 2.835 x 103, 2.277 x 104, and 1.715 x 104 L/mol/cm for Ma to Mc, respectively. The methods were successfully applied to the determination of 7- ADCA in formulations and the results tallied well with the label claim. The results were statistically compared with those of a literature method by applying the student’s t-test and F-test. No interference was observed from the concomitant substances normally added to preparations. The accuracy and validity of the methods were further ascertained by performing recovery experiments via standard-addition method.

Spectrophotometric determination of fluvoxamine as maleate by selective methods.

Simple, accurate and reproducible visible spectrophotometric methods for the assay of drug fluvoxamine as maleate were established based on the formation of oxidative coupling reaction between the corresponding drug, Brucine-NaIO4 and DCQC. The procedures described were applied successfully to the determination of the compound in their dosage forms. The results showed that the proposed procedures compared favorably with the reference methods and satisfactory sensitivity, accuracy and precision. The optical characteristics such as Beer’s law limits, molar absorptivity and sandell’s sensitivity are reported. Regression analysis using the method of least squares was made to evaluate the slope (b), intercept (a) and correlation coefficient (r) and standard error of estimation (Se) for the drug.