Simple and Selective Spectrophotometric Determination of Ofloxacin in Pharmaceutical Formulations Using Two Sulphonphthalein Acid Dyes

Table 1

Comparison of the performance characteristics of the present methods with the published methods.

Sl. no.	Reagent(s) used	Methodology	𝜆max (nm)	Linear range (µg/mL); (ε = L/mol/cm)	Remarks	Reference
1	Ce(IV)-MBTH	Oxidative coupling reaction product measured	640	1–10	Uses expensive reagent; less stable species measured	[23]
2	Citric acid-acetic anhydride	Pink-colored chromogen measured	552	5–55; (ε = 6.04 × 10^3)	Boiling for 20 min required	[24]
3	Iron(III) nitrate	Amber-coloured complex measured	370	0–62.5; NA	Buffers used	[25]
4	Iron(III) chloride/HCl	Yellow complex measured	410	20–160	Less sensitive	[26]
5	(a) Tropaeolin 000 (TP 000)	Red chloroform extractable ion-pair complex measured	485	2.5–30; (ε = 8.24 × 10^3)	Required close pH control and involved extraction steps
	(b) Supracene Violet 3B (SV 3B)	Chloroform extractable ion-pair complex measured	575	2.5–25; (ε = 1.09 × 10^4)		[27]
6	(a) Bromophenol blue	Yellow chloroform extractable 1 : 1 ion-pair complex measured	410	5–25; (ε = 1.04 × 10^4)	Required close pH control and involved extraction steps
	(b) Bromothymol blue		415	2–15; (ε = 2.01 × 10^4)		[28]
	(c) Bromocresol purple		410	2–20; (ε = 1.04 × 10^4)
7	(a) Bromocresol purple	In both methods, resulting yellow-colored ion-pair complexes measured	400	1.0–16.0; (𝜀=2.4×10^4)	Highly sensitive with wide linear dynamic ranges, no heating or extraction step, no pH-adjustment, single step reaction, and inexpensive instrumental setup
	(b) Bromocresol green		410	1.0–16.0; (𝜀=1.96×10^4)		Present methods