Spectrophotometric Determination of Gemifloxacin Mesylate, Moxifloxacin Hydrochloride, and Enrofloxacin in Pharmaceutical Formulations Using Acid Dyes

Table 1

Statistical analysis of calibration graphs and analytical data in the determination of the studied drugs using the proposed methods.

Parameters	GMF					MXF				ENF
	BCG	BCP	BTB	BPB	MO	BCP	BTB	BPB	MO	BCG	BTB
Wavelengths 𝜆max (nm)	420	408	415	416	422	410	415	416	420	419	414
pH	3.0	3.0	3.5	3.5	3.5	3.0	3.5	3.0	3.5	3.0	3.0
Beer’s law limits (µg mL^−1)	1.0–16	1.0–12	2.0–16	1.0–16	3.0–30	1.0–12	2.0–18	1.0–10	2.0–20	2.0–20	2.0–24
Molar absorptivity 𝜀 (L/mol^−1 cm^−1) × 10^4	2.1787	3.9244	1.8904	2.4457	0.9386	3.3572	1.9365	4.1976	1.2876	1.4126	1.198
Sandell’s sensitivity (ng cm^−2)	22.3	12.4	25.7	19.9	51.7	13.0	22.6	10.4	34.0	25.4	30.0
log 𝐾𝑓	5.25±0.13	4.90±0.10	4.95±0.08	5.36±0.12	4.76±0.09	4.86±0.07	4.98±0.11	5.12±0.09	5.20±0.07	4.82±0.12	5.14±0.09
Regression equation^a
Intercept (𝑎)	0.0016	0.0042	0.0087	0.0064	−0.0006	−0.0091	−0.0058	−0.0137	0.0299	0.0066	0.0005
Slope (𝑏)	0.0447	0.0805	0.0382	0.0498	0.0196	0.0764	0.0441	0.0953	−0.0023	0.0393	0.0334
Correlation coefficient (𝑟)	0.9998	0.9999	0.9993	0.9997	0.9996	0.9991	0.9997	0.9994	0.9995	0.9998	0.9995
LOD (µg mL^−1)^b	0.23	0.26	0.52	0.28	0.87	0.21	0.56	0.25	0.41	0.48	0.51
LOQ (µg mL^−1)^b	0.77	0.87	1.73	0.93	2.90	0.70	1.87	0.83	1.37	1.60	1.70
Mean ± SD	99.80±1.14	99.60±0.74	99.90±0.90	99.75±1.05	99.65±0.86	99.95±0.74	100.10±1.07	99.60±0.82	99.70±0.79	100.05±0.98	99.80±0.87
RSD %	1.14	0.74	0.90	1.05	0.86	0.74	1.07	0.82	0.79	0.98	0.87
RE %	1.20	0.77	0.94	1.10	0.90	0.78	1.12	0.86	0.83	1.03	0.91
𝑡-test^c	0.23	0.50	0.19	0.29	0.42	0.01	0.11	0.26	0.19	0.24	0.07
𝐹-test^c	3.49	1.47	2.18	2.96	1.98	1.35	1.54	1.10	1.19	1.24	1.02

^a𝐴=𝑎+𝑏𝐶, where 𝐶 is the concentration in µg mL⁻¹ and 𝑦 is the absorbance units.
bLOD: limit of detection; LOQ: limit of quantification; 𝜀: molar absorptivity.
cThe theoretical values of 𝑡 and 𝐹 at 𝑃=0.05 are 2.571 and 5.05, respectively.