New Sensitive Kinetic Spectrophotometric Methods for Determination of Omeprazole in Dosage Forms

Table 2

Kinetic parameters obtained from Benesi-Hildebrand, Arrhenius, and first-order linear plots of OMZ-acceptor CT complexes at the specific 𝜆_max and reaction temperature.

Kinetic parameters	Iodine method	DDQ method
Correlation coefficient (r)	0.9995	0.9999
Order of CT reaction (n)	0.87	0.99
Specific rate constant, s^−1(𝑘)×10^4	5.45	56.18
Activation energy, kcal mol^−1 (Ea)^♠	−1.54	−1.95
Activation entropy change, kcalmol^−1∘C(Δ𝑆^∘)	−69.96	−66.44
Molar absorptivity, l⋅mol^−1cm^−1(𝜀)×10^3	21.12	6.89
Standard free energy change, kcalmol^−1 (Δ𝐺^∘)	−5.91	−4.80
Association constant, l⋅mol^−1(𝐾𝑐)×10^3	21.50	3.33

   ^♠ : Negative sign of Ea indicates that the CT complex is decomposed by increasing temperature.