Table 2.

The percutaneous permeation parameters of ibuprofen with various EOs through excised rat skin (n = 5).

PE	Flux/μg·cm−2·h−1	ER	Tlag/h	Permeation ratioa/%
Vehicle	9.94 ± 3.36	1.00	7.49 ± 0.37	47.09 ± 11.90
Azone	19.49 ± 2.66**	1.77	7.28 ± 0.93	56.22 ± 12.56
Turpentine oil	24.54 ± 7.90**	2.23	6.16 ± 0.70**	68.80 ± 17.16*
Angelica oil	20.22 ± 5.29**	1.83	7.57 ± 0.27	79.43 ± 5.36***
Chuanxiong oil	28.61 ± 7.66**#	2.60	7.94 ± 0.29	88.41 ± 4.12***#
Cyperus oil	27.37 ± 7.07**#	2.49	7.03 ± 0.73	70.72 ± 15.57*
Cinnamon oil	28.93 ± 7.21***#	2.63	7.78 ± 0.56	81.08 ± 2.09***
Clove oil	21.64 ± 8.00*	1.97	7.52 ± 0.53	71.24 ± 15.85*

^aCumulative amount of permeated ibuprofen at 48 h/added ibuprofen*100%.

^*p < 0.05,

^**p < 0.01,

^***p < 0.001 vs. the vehicle group,

^#p < 0.05 vs. the Azone group.