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

Table 1

Analytical parameters for cited drugs by the proposed UPLC method.

Parameter	PAR	TIZ	ACF	NIM
Linear range (µg·mL^−1)	81.25–487.5	0.5–3.5	25–150	25–150
a (intercept)	958.16	89.25	563.80	−1423.8
Sa (standard deviation of the intercept)	146.30	17.36	323.92	244.29
b (slope)	84.92	1500.4	366.72	412.42
Sb (standard deviation of the slope)	0.47	7.98	3.41	2.362
r (correlation coefficient)	0.9999	0.9999	0.9997	0.9999
r^2 (determination coefficient)	0.9998	0.9998	0.9994	0.9998
SD of residuals (Sy.x)	174.21	22.17	338.72	323.91
LOD (limit of detection, µg·mL^−1)	5.68	0.03	2.92	1.96
LOQ (limit of quantitation, µg·mL^−1)	17.22	0.11	8.83	5.96