Table 1. Intra-/Interday assay precision and accuracy of the HPLC method for the measurement of INH and RIF in local skin of guinea pigs.

Intraday variation				Interday variation
Concentration (μg/mL)	Mean concentration measured	% CV	% Accuracy	Concentration (μg/mL)	Mean concentration measured	% CV	% Accuracy
INH
5	4.3	3.1	85.5	5	4.7	14.1	94.0
25	20.0	1.8	80.0	25	21.3	5.6	85.2
100	94.8	0.7	94.8	100	102.6	6.5	102.6
RIF
2	2.2	6.2	110.0	2	2.7	19.6	135.0
10	9.5	0.6	95.0	10	9.9	3.3	99.0
50	48.7	0.6	97.4	50	50.4	3.1	100.8

Accuracy (%) = 100 × (mean concentration/nominal concentration).

CV (%) = 100 × (standard deviation/mean concentration).