Table 2. Decrease in mean peak height (± SD), compared with control (untreated skin) of asymmetric (Asy) and symmetric (Sym) C-H stretching and C=O stretching absorbance of abdominal hydrated whole skin rat following treatment with different vehicles (mean ± SD, n = 3) .

vehicles	Asymmetric C-H stretching		Symmetric C-H stretching		C=O stretching of lipid ester
	Peak height	%D	Peak height	%D	Peak height	%D
Control	4.877±0.0015	-	5.026+0.0026	-	4.999±0.0065	-
PG	0.021±0.002	99.56±1.05	0.023+0.0041	99.54+1.547	0.013±0.002	99.73±1.41
Span 80	0	100	1.95+0.041	61.2±1.004	1.874±0. 018	62.5±1.015
Tween 80	2.129±0.066	56.34±1.84	2.115±0.055	57.91+1.804	1.872±0.025	62.55±1.215
Labrafac PG	2.092 ±0.008	57.1 ±1.93	1.999±0.078	59.01±2.11	1.944±0.045	61.1±1.312
Transcutol P	1.888±0.012	61.28±2.01	1.850±0.114	63.19±2.29	1.640±0.051	67.19±1.493

*%Decrease in peak height(%D) =( peak height from untreated whole skin - peak height from solvent treated whole skin)/ peak height from untreated whole skin x 100