Table 2. Analysis of the Experimentally Determined AES Profiles as a Function of Time of Reverse Iontophoresis In Vitro and In Vivo for Both SA and NIC using Equation 8 and the Derived Best-Fit Values of ASC,0, AVT,0, k1, and k2a.
|
in vitro (mean ± SD) |
in vivo (mean ± SD) |
||||
|---|---|---|---|---|---|
| drug | parameter | experiment | model best-fit | experiment | model best-fit |
| salicylic acidb | ASC,0 (nmol cm–2) | 19 ± 6.1 | 22 ± 3.6 | 16 ± 8.5e | 13 ± 4.5 |
| AVT,0 (nmol cm–2) | 11 ± 4.3 | 18 ± 8.5 | n.d.d | 7.3 ± 2.5 | |
| k1 (h–1) | n.d.d | 11 ± 2.6 | n.d.d | 10 ± 0.45 | |
| k2 (h–1) | n.d.d | 0.95 ± 0.39 | n.d.d | 0.54 ± 0.30 | |
| nicotineb,c,f | ASC,0 (nmol cm–2) | 127 ± 49 | 188 ± 38b | 453 ± 136e | 335 ± 33 |
| 199 ± 45c | |||||
| AVT,0 (nmol cm–2) | 300 ± 153 | 283 ± 156b | n.d.d | 223 ± 75 | |
| 351 ± 118c | |||||
| k1 (h–1) | n.d.d | 6.4 ± 1.3b | n.d.d | 8.5 ± 1.9 | |
| 5.8 ± 0.74c | |||||
| k2 (h–1) | n.d.d | 0.33 ± 0.15b | n.d.d | 0.65 ± 0.18 | |
| 0.25 ± 0.09c | |||||
a
The value of k3 for NIC was set to 0.20 h–1in vitro and in vivo; for SA, the corresponding values were 0.19 and 0 h–1.
b
RI extraction into chloride/pH 7.4 buffer (n = 6 for SA; n = 8 for NIC).
c
RI extraction into gluconate/pH 6.0 buffer (n = 6 for NIC).
d
Not determined.
e
n = 5 for SA; n = 6 for NIC.
f
Application times are 8 h in vitro and 4 h in vivo.