New Spectrophotometric and Fluorimetric Methods for Determination of Fluoxetine in Pharmaceutical Formulations

Table 1

Summary for the optimization of variables affecting the reaction of FLX with NQS and NBD-Cl reagents employed in the development of the proposed spectrophotometric and fluorimetric methods, respectively.

Variable	Spectrophotometric method		Fluorimetric method
	Studied range	Optimum	Studied range	Optimum
NQS (%, w/v)	0.05–0.8	0.5
NBD-Cl (%, w/v)			0.01–0.5	0.2
pH	6–13	11	5–9.5	8 ± 0.2
Temperature (°C)	25–90	25	25–70	70
Time (minutes)	2–25	10	5–60	20
Diluting solvent	Different(a)	Methanol	Different(a)	Methanol(b)
Measuring wavelength (nm)	400–600	490	400–600	490 (𝜆ex), 545 (𝜆em)

(a)Solvents tested: methanol, ethanol, isopropanol, acetone, acetonitrile, dimethylsulphoxide, and 1,4-dioxane. (b)One milliliter of 0.1 M HCl was added before dilution with methanol.