Table 2.

Microemulsion characteristics and skin permeation rates of evodiamine and rutaecarpine (mean ± standard deviation, n = 3)

Formulations	Mean droplet size (nm)	Polydispersity index	Viscosity (mPa · s)	Skin penetration rate constants (μg/cm2 per h)
				Evodiamine	Rutaecarpine
ME1	48.1 ± 1.5	0.31 ± 0.05	48.61 ± 0.29	0.055 ± 0.001	0.016 ± 0.002
ME2	20.2 ± 1.2	0.10 ± 0.02	37.65 ± 0.14	0.125 ± 0.024	0.038 ± 0.007
ME3	47.5 ± 1.6	0.25 ± 0.06	33.08 ± 0.75	0.112 ± 0.035	0.034 ± 0.004
ME4	42.9 ± 1.6	0.32 ± 0.01	85.24 ± 0.91	0.037 ± 0.006	0.011 ± 0.003
ME5	11.3 ± 0.4	0.48 ± 0.04	53.77 ± 0.39	0.082 ± 0.012	0.015 ± 0.005
ME6	26.8 ± 1.2	0.11 ± 0.02	36.20 ± 0.27	0.060 ± 0.007	0.020 ± 0.003
ME7	29.9 ± 1.0	0.12 ± 0.01	109.18 ± 0.46	0.028 ± 0.005	0.007 ± 0.001
ME8	10.7 ± 0.6	0.49 ± 0.06	65.74 ± 0.82	0.051 ± 0.004	0.013 ± 0.005
ME9	39.6 ± 0.7	0.37 ± 0.07	41.02 ± 0.33	0.058 ± 0.006	0.017 ± 0.004
Suspension	–	–	–	0.011 ± 0.002	0.006 ± 0.001
Ointment	–	–	–	0.027 ± 0.003	0.009 ± 0.001

Abbreviation: mPa · s, millipascal seconds.