Table 2.

Linear correlation coefficients obtained using first order, Higuchi and zero order kinetic models for AA skin permeation.

Kinetic model	Linear correlation coefficient (r)
	AA	DRV1	DRV2	DRV3	DRV4	DRV5
Zero order	0.942	0.881	0.959	0.920	0.925	0.954
Higuchi	0.878	0.934	0.935	0.957	0.964	0.894
First order	0.988	0.577	0.684	0.633	0.636	0.918

Diffusion of 0.2 mL aliquots of liposomal formulations (DRV) or free AA solution (AA) through pig ear skin with stratum corneum was quantified over 24 h.