A validate rapid, economical and sensitive visible spectrophotometric method has been developed for quantitative determination of amprenavir in bulk drug and formulation samples. This method is validated for irinotecan with chromogenic reagent 3-methyl benzothiazolinone hydrazine (MBTH). The calibration curve was linear over Beer’s concentration range of 25-350 μg/ml. The relative standard devi...

1. The oxidation of some para-substituted benzylamines by diamine oxidase produces the corresponding aldehydes. This was studied to develop a spectrophotometric method for following the enzyme reaction, as the aldehydes produced absorb strongly at 250nm where the substrates are almost optically transparent. 2. p-Dimethylaminomethylbenzylamine was the most useful substrate and full details of it...

In this paper, methods of sample preparation for potentiometric measurement of phenylalanine are presented. Basing on the spectrophotometric measurements of phenylalanine, the concentrations of reagents of the enzymatic reaction (10 mM L-Phe, 0,4 mM NAD, 2U L-PheDH) were determined. Then, the absorption spectrum of the reaction product, NADH, was monitored (maximum peak at 340 nm). The results ...

A simple and sensitive extraction-spectrophotometric method for rapid and accurate determination of benzocaine in pure and dosage forms was developed. Benzocaine was effectively extracted as a 1:1 ion pair complex with dicyclohexyl18-crown-6 and calmagite in acidic media into chloroform, followed by spectrophotometric determination at 486 nm. Molar absorptivity of the ternary complex at this wa...

We describe an ultramicromethod for determination of uric acid by a manual procedure. Hydrogen peroxide, formed when uric acid is oxidized in the presence of uricase, oxidatively couples two molecules of p-hydroxyphenylacetic acid in the presence of peroxidase to produce a highly fluorescent compound. The specificity of the uricase reaction is retained, and the fluorometry results in a higher s...

A simple, specific, accurate and precise spectrophotometric stability indicating method is developed for determination of itraconazole in the presence of its oxidative degradation product and in pharmaceutical formulations. A newly developed spectrophotometric method called ratio difference method by measuring the difference in amplitudes between 230 and 265 nm of ratio spectra. The calibration...