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

Table 2

Intraday and interday accuracy and precision for CS in methanol.

	Nominal concentration (μg/mL)
	0.1	0.25	0.5	0.75	1	2.5
Intraday
Day 1; Mean (N = 6)	0.114	0.276	0.511	0.660	1.030	2.510
SD	0.020	0.033	0.049	0.038	0.100	0.152
Accuracy (% error)	13.743	10.389	2.106	12.052	3.047	0.387
Precision (% RSD)	17.582	11.907	9.667	5.691	9.735	6.058
Day 2; Mean (N = 6)	0.119	0.237	0.546	0.639	1.057	2.502
SD	0.021	0.027	0.039	0.027	0.147	0.144
Accuracy (% error)	19.194	5.204	9.123	14.785	5.736	0.069
Precision (% RSD)	17.446	11.294	7.085	4.277	13.949	5.745
Day 3; Mean (N = 6)	0.102	0.230	0.497	0.803	0.968	2.499
SD	0.018	0.030	0.055	0.090	0.057	0.178
Accuracy (%error)	2.485	8.070	0.622	7.103	3.172	0.030
Precision (%RSD)	17.454	13.132	11.123	11.216	5.882	7.108
Interday
Average concentration (μg/mL)	0.112	0.248	0.518	0.701	1.019	2.504
SD	0.020	0.035	0.050	0.093	0.109	0.149
Accuracy (% error)	11.807	0.962	3.536	6.578	1.870	0.142
Precision (% RSD)	17.667	14.174	9.659	13.289	10.657	5.948