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Detection of Decomposition and Analytical Interferences in Pharmaceutical Preparations Containing Corticosteroids

1970; Elsevier BV; Volume: 59; Issue: 8 Linguagem: Inglês

10.1002/jps.2600590820

1520-6017

Robert Graham, Patricia A. Williams, Charles T. Kenner,

Analytical Chemistry and Chromatography

Since the blue tetrazolium and phenylhydrazine reagents for corticosteroids react with the intact side chain at C17, and the isonicotinic acid hydrazide method and UV spectro-photometry depend upon conjugation in Ring A at the other end of the molecule, the analytical results by the four methods give information concerning decomposition caused by oxidation of the C17 side chain and by deconjugation in Ring A. Methods are proposed which allow the detection and determination of both acidic and neutral decomposition products. Measurement of the variation of absorbance with time can be used to detect unidentified interferences in the blue tetrazolium, phenylhydrazine, and isonicotinic acid procedures. The extent of interference of several substances which interfere in at least one of the color reactions is reported. Several examples of the use of the proposed methods to detect and determine decomposition and/or interference are given.