Determination of low levels of phenothiazine sulphoxides in phenothiazine drug substances and formulations by thin-layer chromatography-second-derivative spectrofluorimetry

Second-derivative spectrofluorimetric determination of sulphoxide impurity in phenothiazine drug substances and formulations

“…10 A combined TLCsecond-derivative spectrofluorimetric assay allows the determination of the sulphoxide in phenothiazines and their formulations at levels down to 0.01% of the phenothiazine concentrations. 11 The objective of this study was to investigate the application of a direct secondderivative spectrofluorimetric assay of the phenothiazine sulphoxides in phenothiazine drug substances and formulations, with the particular aim of providing adequate sensitivity in order to allow the accurate and precise determination of low concentrations of the sulphoxide in phenothiazines of pharmacopoeial quality, in which the maximum level of sulphoxide permitted is 0.5% d m .…”

Second-derivative spectrofluorimetric determination of sulphoxide impurity in phenothiazine drug substances and formulations

“…10 A combined TLCsecond-derivative spectrofluorimetric assay allows the determination of the sulphoxide in phenothiazines and their formulations at levels down to 0.01% of the phenothiazine concentrations. 11 The objective of this study was to investigate the application of a direct secondderivative spectrofluorimetric assay of the phenothiazine sulphoxides in phenothiazine drug substances and formulations, with the particular aim of providing adequate sensitivity in order to allow the accurate and precise determination of low concentrations of the sulphoxide in phenothiazines of pharmacopoeial quality, in which the maximum level of sulphoxide permitted is 0.5% d m .…”

Second-derivative spectrofluorimetric determination of sulphoxide impurity in phenothiazine drug substances and formulations

“…10 A combined TLCsecond-derivative spectrofluorimetric assay allows the determination of the sulphoxide in phenothiazines and their formulations at levels down to 0.01% of the phenothiazine concentrations. 11 The objective of this study was to investigate the application of a direct secondderivative spectrofluorimetric assay of the phenothiazine sulphoxides in phenothiazine drug substances and formulations, with the particular aim of providing adequate sensitivity in order to allow the accurate and precise determination of low concentrations of the sulphoxide in phenothiazines of pharmacopoeial quality, in which the maximum level of sulphoxide permitted is 0.5% d m .…”

Second-derivative spectrofluorimetric determination of sulphoxide impurity in phenothiazine drug substances and formulations

“…10 A combined TLCsecond-derivative spectrofluorimetric assay allows the determination of the sulphoxide in phenothiazines and their formulations at levels down to 0.01% of the phenothiazine concentrations. 11 The objective of this study was to investigate the application of a direct secondderivative spectrofluorimetric assay of the phenothiazine sulphoxides in phenothiazine drug substances and formulations, with the particular aim of providing adequate sensitivity in order to allow the accurate and precise determination of low concentrations of the sulphoxide in phenothiazines of pharmacopoeial quality, in which the maximum level of sulphoxide permitted is 0.5% d m .…”