ABSTRACT
In acidic medium, stanozolol reacts with phenoldisulfonic acid to form a stable yellow chromophore, which is quantitated by spectrophotometry at 385 nm. The reaction gives a linear response at concentrations from 5 to 50 micrograms/mL. The method is suitable for routine analytical control of stanozolol and its formulations.
Subject(s)
Stanozolol/analysis , Chemical Phenomena , Chemistry , Colorimetry/methods , Drug Stability , Spectrophotometry, Ultraviolet/methods , Suspensions/analysis , Tablets/analysisABSTRACT
A sensitive spectrophotometric method is reported for the quantitative determination of pentaerythritol tetranitrate in tablets. The method is based on reduction of pentaerythritol tetranitrate with zinc and calcium chloride, and reaction of the nitroso compound thus formed with 1-naphthylamine in acidic medium. The reaction gives a purple product having an absorbance maximum at 545 nm. Beer's law is obeyed in the concentration range of 1-10 micrograms/mL of reaction mixture. The presence of meprobamate in tablets does not interfere with the proposed analytical determination.
Subject(s)
Pentaerythritol Tetranitrate/analysis , Calcium Chloride , Colorimetry , Indicators and Reagents , Spectrophotometry, Ultraviolet/methods , Tablets , ZincABSTRACT
A precise colorimetric procedure is proposed for estimation of ethambutol hydrochloride, based on reaction of the drug with 2,4-dinitro-1-fluorobenzene under stipulated conditions. The yellow chromophore is quantitated spectrophotometrically at 376 +/- 1 nm. The relationship between absorbance and drug concentration was linear within a range of 5-40 micrograms/mL. The method is suitable for the analytical control of ethambutol HCl and its formulations.
