Spectrophotometric Simultaneous Determination of Salbutamol Sulfate and Ketotifen Fumarate in Combined Tablet Dosage Form by First-Order Derivative Spectroscopy Method

Table 4

Regression analysis data and summary of validation parameters for proposed methods.

Parameters	First derivative method
	Salbutamol sulfate	Ketotifen fumarate
Wavelength	257 nm	278 nm
Linearity range (μg/mL)	5–45 μg/mL	5–35 μg/mL
Slope (m)	0.0002	0.0011
Intercept (c)	0.000006	0.0004
Correlation coefficient (𝑟^2)	0.9998	0.9998
LOD (μg/mL)	0.55	0.06
LOQ (μg/mL)	1.66	0.18
%Recovery	98.82%–101.19%	98.34%–100.81%
Precision (RSD) %
Repeatability (𝑛=6)	1.30	0.23
Interday (𝑛=3)	0.43–1.02	0.17–0.34
Intraday (𝑛=3)	0.37–0.91	0.05–0.15