Spectrophotometric determination of isoniazid in presence of rifampicin in some pharmaceutical preparations and urine, using isatin as a reagent

A simple and sensitive Spectrophotometric method for the determination of isoniazid [INH] that is potent antituberculosis, based on the formation of a condensation product with isatin in aqueous solution at pH 1.4, has been developed. The condensation product [isatin-isonicotinylhydrazone] was found to possess a strong absorption at 340 nm. Using 1.6 mM concentration of isatin in solution, the maximum absorbance was attained after standing for 40 min at room temperature. Calibration graph was found to be rectilinear and Beer's law was obeyed in the range 0-32 ppm of isoniazid, with the molar absorpitivity [summation] = 1.2 x 10[4] and a lower detection limit 0.5 ppm. The analysis of different forms of some pharmaceutical preparations containing isoniazid in presence of rifampicin has been carried out after the extraction of the latter with CHC13 from the sample solution containing the condensation product. The extraction of rifampicin was found to be quantitative and very rapid so that shaking for few seconds was enough. The determination of INH in presence of rifampicin in urine samples has been performed

Spectrophotometric determination of phenylephrine using P-aminophenol and potassium periodate

A fast and sensitive method has been developed for the determination of Phenylephrine hydrochloride [PE] in pharmaceutical preparations. The method is based on the reaction between PE and p-aminophenol [PAP] in presence of KIO[4] at pH 10. The absorbance of solution is measured at [lambda [max]] 640 nm. Beer's law is obeyed over the concentration range from 15 to 100 micro g ml[-1], and the extinction coefficient was calculated to be 1.01 x 10[3] 1 mol[-1] cm[-1]. The different analytical parameters have been investigated. The method has been successfully applied to determine PE in some pharmaceutical preparations

Isatin isonicotinoyl hydrazone complexes of tervalent metals Ti, Zr, Sn, Pt, and Th

Two forms of isatin isonicotinoyl hydrazone have been prepared. Analytical, t.g.a., electronic, i.r. and n.m.r. results show that the orange form [H.G.] is the anti-tautomer hydrazone whereas the yellow form [H.Y]. 1/2H[2]O is a mixture of imide-imidol of the syn one stabilized by H-bond through H-chelates. The complexes of Ti, Zr, Sn, Pt and Th with HG and HY were prepared and characterized using a variety of analytical, spectral and thermal measurements. The analytical data showed that 1:1 or 1:2 molar compounds were obtained. The title hydrazone behaved as a neutral or monobasic bidentate ligand coordinating through the azomethine N and isatin O or eventually as tridentate coordinating through O, N and pyridine N