Development and Validation of Ecofriendly HPLC-MS Method for Quantitative Assay of Amoxicillin, Dicloxacillin, and Their Official Impurity in Pure and Dosage Forms

Table 1

Validation analytical parameters of the developed HPLC/MS method for the simultaneous assessment of AMOX, DIC, and 6-APA.

Parameter	AMOX	DIC	6-APA
Calibration range (µg mL^−1)	2–28	2–35	1–10
Slope	0.1027	0.0999	0.4803
Intercept	0.1656	0.0042	0.0388
Mean %	99.67%	99.97%	100.20%
SD	1.751	1.285	1.145
Correlation coefficient (r)	0.9997	0.9998	0.9997
LOD	0.436	0.539	0.232
LOQ	1.322	1.634	0.702
RSD%^a	0.132–0.885 – 0.463	0.533–0.186–0.764	0.787–0.238 – 0.519
RSD%^b	1.341–1.702 – 0.945	1.556–0.820–1.174	1.540–1.306 – 1.169

Limit of detection and quantitation are mathematically calculated (LOD = 3.3 × SD of the response/slope, LOQ = 10 × SD of the response/slope). (RSD%)^a and (RSD%)^b, the intra- and interday relative standard deviations of concentrations (4, 12, and 24 µg mL⁻¹) for AMOX, (5, 15, and 25 µg mL⁻¹) for DIC, and (2, 6, and 10 µg mL⁻¹) for 6-APA.