Table 1.

Permeation parameters of the parent tetrapeptide and its N-terminal and C-terminal C₇-acyl lipid conjugates

Compound	Cumulative amount in receptor after 24 hours (µg ± SEM)	Epidermal flux (µg⋅cm−2·h−1)	Estimated log P using ChemAxon®	Observed log P	Observed log D
L-AAPV	Undetectable	Undetectable	−1.25	N/A	−2.96 (pH 4.5), −2.92 (pH 9)
L-C7-AAPV	115.53±26.06	8.11	1.06	0.30 (pH 4.5)	−0.79 (pH 9)
L-AAPV-C7	116.02±27.9	8.36	0.86	0.37 (pH 9)	0.13 (pH 4.5)

Note: Partition coefficient data are of observed experimental results versus those estimated using a computer software program.

Abbreviations: SEM, standard error of the mean; L-AAPV, L-Ala-L-Ala-L-Pro-L-Val; N/A, not available; L-C₇-AAPV, C₇-L-Ala-L-Ala-L-Pro-L-Val; L-AAPV-C₇, L-Ala-L-Ala-L-Pro-L-Val-C₇.