Development and Validation of a Liquid Chromatography-Mass Spectrometry Assay for Determination of Cromolyn Sodium in Skin Permeation Studies

Table 1

Intraday and interday accuracy and precision for CS in 1X PBS.

	Nominal concentration (μg/mL)
	0.1	0.25	0.5	0.75	1	2.5
Intraday
Day 1; Mean (N = 6)	0.095	0.243	0.481	0.724	1.074	2.483
SD	0.016	0.024	0.061	0.072	0.117	0.215
Accuracy (% error)	4.632	2.904	3.732	3.497	7.378	0.680
Precision (% RSD)	17.1	9.743	12.701	9.914	10.937	8.657
Day 2; Mean (N = 6)	0.094	0.221	0.498	0.761	1.042	2.483
SD	0.016	0.028	0.064	0.082	0.073	0.141
Accuracy (% error)	5.946	11.485	0.342	1.458	4.21	0.667
Precision (% RSD)	17.531	12.482	12.907	10.81	6.97	5.668
Day 3; Mean (N = 6)	0.112	0.282	0.473	0.732	0.989	2.511
SD	0.022	0.02	0.049	0.105	0.143	0.158
Accuracy (% error)	12.109	12.964	5.347	2.466	1.077	0.459
Precision (% RSD)	19.442	6.979	10.297	14.368	14.415	6.306
Interday
Average concentration (μg/mL)	0.101	0.249	0.484	0.739	1.035	2.493
SD	0.019	0.034	0.056	0.084	0.113	0.164
Accuracy (% error)	15.989	11.511	10.18	9.201	8.34	4.965
Precision (% RSD)	19.123	13.817	11.551	11.345	10.963	6.590