Simultaneous Estimation of Paracetamol, Ambroxol Hydrochloride, Levocetirizine Dihydrochloride, and Phenylephrine Hydrochloride in Combined Tablet Formulation by First-Order Derivative Spectrophotometry

Table 4

Intraday and interday precision data of PARA, AMB, LEVO and PHEN.

Drug	Amount labeled (mg/tab)	Percentage obtained (𝑛=6)		SD		% RSD
		Intraday	Interday	Intraday	Interday	Intraday	Interday
PARA	500	99.47	99.60
	500	98.61	99.48	0.4936	0.0723	0.4977	0.0726
	500	99.46	99.61
Mean		99.18	99.56
AMB	60	98.56	97.85
	60	100.44	100.83	0.9408	1.6197	0.9453	1.6244
	60	99.57	100.44
Mean		99.52	99.72
LEVO	2.5	99.88	100.01
	2.5	100.01	99.88	0.0750	0.0751	0.0752	0.0750
	2.5	99.88	100.01
Mean		99.92	99.96
PHEN	5	98.21	98.34
	5	98.34	98.22	0.0750	0.0752	0.0765	0.0763
	5	98.21	98.34
Mean		98.25	98.29

SD: standard deviation; RSD: relative standard deviation; CI: confidence interval; SE: standard error.