Development and Validation of a Versatile UPLC-PDA Method for Simultaneous Determination of Paracetamol, Tizanidine, Aceclofenac, and Nimesulide in Their New Combinations

Table 2

Analytical parameters of system suitability tests for the proposed UPLC method.

Parameter	Reference value	PAR	TIZ	ACF	NIM
Flow rate (mL/min)	—	1.25
Retention time (min)	—	1.42	2.32	3.63	5.63
Resolution (R)	R > 1.5	—	7.16	4.81	9.21
K′ (column capacity)	>2	5.48	9.55	15.51	24.59
Symmetry	—	1.24	1.40	1.18	1.18
Tailing factor (T)	≤2	1.22	1.38	1.16	1.21
N (column efficiency)	≥2000	2979.69	3036.93	5090.82	6074.17
HETP	=L/N	0.033	0.032	0.019	0.016

Mean of three determinations.