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

Table 3

Standard addition method for the calculation of percentage of studied drugs in their pharmaceutical dosage forms using the UPLC method.

Mixture number	Amount taken (µg·mL^−1)			Amount added (µg·mL^−1)			Amount found (µg·mL^−1)			% recovery
Nicip plus tablets
	NIM	PAR		NIM	PAR		NIM	PAR		NIM	PAR
1	50.0	162.5		25.0	81.25		74.21	243.98		98.95	100.94
2	50.0	162.5		50.0	162.5		98.01	323.01		98.01	99.39
3	50.0	162.5		75.0	243.75		125.69	405.34		100.55	99.78
Zerodol MR tablets
	ACF	TIZ		ACF	TIZ		ACF	TIZ		ACF	TIZ
1	50.0	1.0		25.0	1.0		76.19	1.97		101.59	98.50
2	50.0	1.0		50.0	1.5		99.22	2.53		99.22	101.20
3	50.0	1.0		75.0	2.0		124.14	2.96		99.31	98.67
Zerodol P tablets
	ACF	PAR		ACF	PAR		ACF	PAR		ACF	PAR
1	50.0	162.5		25.0	81.25		76.45	244.10		101.93	100.14
2	50.0	162.5		50.0	162.5		101.82	325.88		101.82	100.27
3	50.0	162.5		75.0	243.75		124.44	404.39		99.55	99.54
Nobel MR tablets
	NIM	PAR	TIZ	NIM	PAR	TIZ	NIM	PAR	TIZ	NIM	PAR	TIZ
1	50.0	162.5	1.0	25.0	81.25	1.0	75.09	242.99	1.99	100.12	99.69	99.50
2	50.0	162.5	1.0	50.0	162.5	1.5	97.99	323.89	2.44	97.99	99.66	97.60
3	50.0	162.5	1.0	75.0	243.75	2.0	123.66	405.30	3.07	98.93	99.77	102.33

Average of three determinations.