Green Analytical Methods for the Separation of Seven Antihistamines: Application in Separation of Azelastine and Related Impurities in Nasal Solution

Table 2

Optimum chromatographic conditions for separation of seven antihistaminic drugs.

Drug	Mobile Phase; ACN:H2O (pH 2.1)	Flow variation; (0.8-1.2 mL min^−1)	Injection volume variation; (2 – 20 μL)	Detection; (nm)	Retention factor; (k’)	Peak Asymmetry; (As)	Theoretical plates; (N/m)
Azelastine HCl	35:65 (v/v)	1.0	20	287	1.52	1.34	14390
Desloratadine	15:85 (v/v)	1.0	20	275	1.26	1.32	15052
Ebastine	45:55 (v/v)	1.0	20	254	1.54	1.60	12698
Fexofenidine HCl	32:68 (v/v)	1.0	20	217	1.10	1.04	14720
Ketotifen	25:75 (v/v)	1.0	20	296	0.82	1.79	12512
Loratadine	35:65 (v/v)	1.0	20	271	1.26	1.38	15680
Olopatadine HCl	25:75 (v/v)	1.0	20	296	1.63	1.33	15412

Optimum value for each drug.
N/m: theoretical plates per meter.