SPECTROPHOTOMETRIC DETERMINATION OF THE ANTIHISTAMINES, CARBINOXAMINEMALEATE AND DOXYLAMINE SUCCINATE, IN AN N-CETYLPYRIDINIUM CHLORIDE MICELLAR MEDIUM
L. Monferrerpons et al., SPECTROPHOTOMETRIC DETERMINATION OF THE ANTIHISTAMINES, CARBINOXAMINEMALEATE AND DOXYLAMINE SUCCINATE, IN AN N-CETYLPYRIDINIUM CHLORIDE MICELLAR MEDIUM, Analytical letters, 29(8), 1996, pp. 1399-1413
The pyridine antihistamines carbinoxamine maleate and doxylamine succi
nate were derivatized by hydrolysis with cyanogen bromide and coupling
with aniline to form a polymethine dye, and determined by colorimetry
. In a micellar cationic medium of N-cetylpyridinium chloride (NCPC),
the reaction times were reduced and the sensitivities improved. In 0.1
M NCPC the apparent molar absorptivities of the derivatives were 5,90
0 and 3,500 M(-1) cm(-1), and the limits of detection (as 3s) were 8.6
x 10(-7) M and 1.7 x 10(6) M, for carbinoxamine and doxylamine, respe
ctively. The sensitivity was enhanced in a three- to six-fold factor w
ith respect to a nonmicellar medium. The reproducibility was 0.8% for
1.6 x 10(-4) M carbinoxamine, and 1.8% for 1.3 x 10(-4) M doxylamine.
The procedure was applied to the evaluation of the drugs in pharmaceut
ical preparations.