Scientia Pharmaceutica, cilt.63, sa.3, ss.207-222, 1995 (SCI-Expanded)
Two new methods are described for the simultaneous determination of analgin and phenobarbital in their binary mixture. In the first method, derivative UV spectrophotometry, the dA/dλ values were read at 291,8 nm for analgin and at 219,4 nm for phenobarbital in the first derivative spectra of the solution of mixture in methanol. In the second, extractive spectrophotometry + derivative spectrophotometry, analgin and phenobarbital were both extracted with tropeoline OO into chloroform from their aqueous solution acidified with sulfuric acid, phenobarbital was determined by measuring the absorbance of the chloroform layer at 422,6 nm and the quantification of analgin was made by reading the dA/dλ values at 274,0 nm in the first derivative sectra of the same layer. Mean recoveries and the relative standard deviations of the methods were assessed. These two methods were successfully applied to a pharmaceutical formulation (suppository) containing analgin and phenobarbital. The results were compared with those obtained by the official method.