Abstract
Simple, accurate, rapid, and sensitive spectrofluorimetric methods for the determination of levosulpiride in pharmaceutical formulation were developed utilizing its fluorescence reaction with Fe
3+
(method
A
) and Al
3+
(method
B
). The calibration curves were found to be linear in the concentration range 0.239–3.44 μg/mL and 0.310–2.730 μg/mL with limit of detection 0.005 μg/mL and 0.0032 μg/mL, respectively, for method
A
and method
B
. The reaction conditions were studied and optimized. In addition, the complexation of Mg
2+
and Ca
2+
was also studied. In all cases, an enhancement in fluorescence emission of levosulpiride upon formation of complex with metal ions was observed. A 2: 1 (drug: metal) stoichiometry for all the complexes was established. Benesi-Hildebrand method was applied for calculation of association constant at 25 and 35°C. The thermodynamic parameters obtained in this study revealed that the interaction process was spontaneous and mainly Δ
S
-driven.