A Stability Indicating UPLC Method for the Determination of Tramadol Hydrochloride: Application to Pharmaceutical Analysis

Table 4

Method robustness.

Condition	Modification	Mean Peak area ± SD*	%RSD	Mean Rt ± SD*	%RSD	Mean theoretical plates ± SD*	%RSD	Mean tailing factor ± SD*	%RSD
	35°C	6207527±6506	0.10	2.015 ± 0.006	0.30	3467 ± 59.65	72	1.10 ± 0.02	0.18
Temperature	40°C	6136916 ± 10695	0.17	2.007 ± 0.007	0.33	3953 ± 85.36	16	1.01 ± 0.01	0.10
	45°C	6186601 ± 6723	0.11	1.99 ± 0.006	0.30	3998 ± 56.56	41	1.11 ± 0.02	0.18
Mobile phase composition	40 : 60	6134526 ± 10115	0.16	1.9 ± 0.006	0.30	4021 ± 10536	62	1.02 ± 0.05	0.49
	50 : 50	6188507 ± 9437	0.15	2.0 ± 0.006	0.30	4068 ± 70.56	73	1.01 ± 0.04	0.40
	60 : 40	6345681 ± 9986	0.16	1.99 ± 0.08	0.40	4098 ± 86.97	12	0.98 ± 0.05	0.51
	0.35	7107242 ± 8520	0.12	2.01 ± 0.05	0.25	3987 ± 101.16	53	1.02 ± 0.02	0.20
Flow rate	0.40	6112464 ± 8817	0.14	2.006 ± 004	0.20	4016 ± 88.84	19	1.02 ± 0.03	0.29
	0.45	5455471 ± 9053	0.17	1.99 ± 0.05	0.25	3987 ± 101.16	53	1.02 ± 0.02	0.20
	224 nm	7024544 ± 15608	0.22	2.00 ± 0.06	0.30	3136 ± 95.16	03	1.01 ± 0.03	0.30
Wavelength	226 nm	6128799±10636	0.18	2.01 ± 0.08	0.40	4268 ± 101.3	10	1.01 ± 0.04	0.40
	228 nm	7131156 ± 12845	0.18	2.00 ± 0.004	0.20	3334 ± 88.58	66	1.02 ± 0.08	0.78

*Mean value of three determinations.