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

Table 1

Regression analysis data and summary of validation parameters for the proposed method.

Parameters	First derivative spectrophotometric method
	PARA*	AMB*	LEVO*	PHEN*
Wavelength	305.5 nm	321 nm	244 nm	280 nm
Linearity range (μg/mL)	20–140	10–70	10–70	10–70
Slope (m)	0.00012	0.00026	0.00119	0.00051
Intercept (c)	−0.0002	−0.000064	0.000085	0.00031
Correlation coefficient (𝑟^2)	0.9992	0.9990	0.9990	0.9995
LOD (μg/mL)	0.0352	0.0373	0.0645	0.0557
LOQ (μg/mL)	0.1070	0.1132	0.1954	0.1687
% Recovery	99.77–99.96	99.28–101.07	99.80–100.95	100.27–100.31
Precision ( RSD) %
Repeatability (𝑛=6)	0.1661	1.9231	1.6141	1.1750
Interday (𝑛=3)	0.0726	1.6244	0.0750	0.0763
Intraday (𝑛=3)	0.4977	0.9453	0.0752	0.0765

∗Mean of six observations.