Table 1.

pH Optimization of phosphate buffer

Mobile phase	Retention Capacity (k/)	Theoretical plates (N)	Tailing Factor (T)	Resolution (R)	Peak shape
Methanol: Phosphate Buffer
pH 2.8 (62:38)
Moxifloxacin		4521	1.17		+++
Prednisolone	0.92	6568	1.01	13.66	+++
Methanol: Phosphate Buffer
pH 3.5 (62:38)
Moxifloxacin		4251	1.29		+++
Prednisolone	0.84	5784	1.18	12.24	+++
Methanol: Phosphate Buffer
pH 4.5 (62:38)
Moxifloxacin		4122	1.47		+++
Prednisolone	0.54	5541	1.14	9.45	---
Methanol: Phosphate Buffer
pH 6.5 (62:38)
Moxifloxacin		3801	1.40		+++
Prednisolone	0.41	4787	1.28	11.87	---

Chromatographic conditions, mobile phase methanol: 0.018 M phosphate buffer 62:38, pH 2.8, or 3.5, or 4.5, or 6.5, Column BDS Hypersil C8 (250 X 4.6, 5 μm), flow rate 1.5 mL min^-1,

injection volume 20 μL, wavelength 254 nm, +++ is peak acceptable and --- is peak not acceptable.