Сборник V международной

Purpose of the study. Develop a reaction method for the identification o f dexamethasone in sub­
stances, as well as in dosage forms.
Methods. To identify dexamethasone, we took ethyl alcohol instead of methyl alcohol. To identi­
fy dexamethasone in an alcoholic solution, when isoniazid is added at a temperature o f 70-800 and with 
benzene sulfanilamide preparations, para-aminobenzoic acid preparations, the reaction gives a persistent 
yellow color.
In addition, the drug, due to the oxidation o f the C17 position o f a-ketal (-COCH2OH) with the 
Fehling reagent, gives a red precipitate. The authenticity of dexamethasone in substances is determined by 
the polarimetric method. Also at the expense of oxygen, instead o f ethyl alcohol, the reaction is carried out 
in methyl alcohol with a phenylhydrazone reagent, which gives a slightly yellow color.
A thin-layer chromatographic method for the analysis o f the drug was studied and developed. In the 
alcohol-benzene system (10:1) gives an R f value of 0.42 ± 0.002.
The developer is a 1% alcohol solution o f isoniazid with acidified sulfuric acid, which gives a yellow 
color when heated.
The developed identification methods can be used for substances and medicinal forms, as well as to 
identify the drug in biological objects (in urine and blood).
Results and discussions. Dexamethasone gives a yellow color with isoniazid, norsulfazole and 
anesthesin reagents. In the TLC method, the following results o f dexamethasone were obtained: with a 
solution of ethyl alcohol Rf-0.64, with chloroform 0.60, with BAW (butanol-acetic acid-water) and with 
Alcohol-benzene (10:1) Rf-0.42.
Conclusion. Identification reactions o f dexamethasone in substances and in tablets with isoniazid 
reagent, as well as with preparations containing primary amine groups developed.
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