Af. Shoukry et al., Spectrophotometric determination of dipyridamole and chlorpheniramine maleate using some chromotropic acid azo dyes, ANAL LETTER, 34(10), 2001, pp. 1689-1701
A simple, accurate and highly sensitive spectrophotometric method is propos
ed for the rapid determination of Dipyridamole using p-chlorophenylazo chro
motropic acid (p-Cl) and 2-(p-nitrophenylazo)-chromotropic acid (C2B) and C
hlorpheniramine maleate using p-chlorophenylazo chromotropic acid (p-Cl), p
-iodophenylazo chromotropic acid (p-I), 2-(p-nitrophenylazo)-chromotropic a
cid (C2B) and 2-(phenylazo)-chromotropic acid (C2R). The method consists of
extracting the ion-associates into methylene chloride. The ion-associates
exhibit absorption maxima at 544 and 524 nm for p-Cl and C2B with Dipyridam
ole, and at 540, 524, 536 and 524nm for p-Cl, p-I, C2B and C2R with Chlorph
eniramine maleate, respectively. Dipyridamole can be determined up to 3.50
and 3.78 mg ml(-1) using p-Cl and C2B. respectively, while Chlorpheniramine
maleate can be determined up to 3.10, 2.36, 1.90 and 1.70 mg ml(-1) using
p-Cl, p-I, C2B and C2R, respectively. The stoichiometric ratio of the ion-a
ssociates was estimated. The molar absorptivity and Sandell sensitivity of
the reaction products were calculated. Statistical treatment of the results
reflects that the procedure is precise, accurate and easily applied for th
e determination of the drugs under investigation in pure form and in their
pharmaceutical preparations.