Spectrofluorimetric determination of 3-methylflavone-8-carboxylic acid, the main active metabolite of flavoxate hydrochloride in human urine.

A simple, sensitive and selective spectrofluorimetric method has been developed for the determination of 3-methylflavone-8-carboxylic acid as the main active metabolite of flavoxate hydrochloride in human urine. The proposed method was based on the measurement of the native fluorescence of the metabolite in methanol at an emission wavelength 390 nm, upon excitation at 338 nm. Moreover, the urinary excretion pattern has been calculated using the proposed method.

Different techniques for the determination of tofisopam.

Five simple and sensitive methods were developed for the determination of tofisopam (TF). The first four are stability-indicating depending on the determination of TF in the presence of its degradation product, while the fifth depended on the determination of TF via its degradation product. Method A was based on first and second derivative spectrophotometry, D and 2D, measuring the amplitude at 298 and 332 nm in the case of 1D and at 312 and 344 nm in the case of 2D.

Different stability-indicating chromatographic techniques for the determination of netobimin.

Two simple, accurate, and sensitive methods were developed for the determination of netobimin in the presence of its degradation product. Method (A) was an HPLC method, performed on C18 column using acetonitrile/methanol/0.01 M potassium dihydrogen phosphate (56 : 14 : 30 by volume) as a mobile phase with a flow rate of 0.

Stability-indicating methods for the determination of racecadotril in the presence of its degradation products.

Three stability-indicating methods were developed for the determination of racecadotril (RCT) in the presence of its alkaline degradation products. The first was an HPLC method in which efficient chromatographic separation was achieved on a C18 analytical column and a mobile phase of acetonitrile-methanol-water-acetic acid (52:28:20:0.1, v/v/v/v).

Reversed-phase high performance liquid chromatographic method for the determination of lansoprazole, omeprazole and pantoprazole sodium sesquihydrate in presence of their Acid-induced degradation products.

A simple sensitive, selective and accurate reversed-phase high performance liquid chromatographic method was developed and validated for the quantitative determination of lansoprazole, omeprazole and pantoprazole sodium sesquishydrate in the presence of their acid-induced degradation products. The three compounds were monitored at 280 nm using Nova-Pak C(18) column and a mobile phase consisting of 0.05 M potassium dihydrogen phosphate : methanol : acetonitrile (5 : 3 : 2 v/v/v).