Route of Administration Transdermal Oral

Location

Dose Site

Untreated skin

Untreated skin

Time after administration (h)

168

192

312

168

192

312

168

192

312

                                            Animal Identification

6003

6004

6007

6003

6004

6007

3003

3004

3007

Skin layer / Compartment g

 

 

 

 

 

 

 

 

 

Epidermis

 

 

 

 

 

 

 

 

 

Pigmented hair shaft 10

 

 

 

 

 

 

 

 

 

                                     Silver grain density score

3

2

2

2

2

0

1

1

0

Keratin

 

 

 

 

 

 

 

 

 

                                     Silver grain density score

3

0

0

0

0

0

0

0

0

Upper and Mid‑Dermis

 

 

 

 

 

 

 

 

 

Collagen

 

 

 

 

 

 

 

 

 

                                     Silver grain density score

3

2

2

2

1

1

2

2

2

Deep Dermis

 

 

 

 

 

 

 

 

 

Collagen

 

 

 

 

 

 

 

 

 

                                   Silver grain density score

2

2

2

2

1

1

1

2

1

Hair bulb

 

 

 

 

 

 

 

 

 

                                   Silver grain density score

3

2

1

2

1

1

1

2

1

Blood vessel lumen

 

 

 

 

 

 

 

 

 

                                   Silver grain density score

2

2

2

2

1

0

1

0

2

Subcutis

 

 

 

 

 

 

 

 

 

Collagen

 

 

 

 

 

 

 

 

 

                                   Silver grain density score

2

1

2

1

1

11

1

1

1

Blood vessel lumen

 

 

 

 

 

 

 

 

 

                                   Silver grain density score

1

1

1

1

1

11

1

1

0

9Autoradiography scored on a 5-level scale for silver grain density
10Refers to silver grains observed within and/or adjacent to hair shafts
11Subcutis not present on section

Table 4: Microautoradiographic Analysis of Skin Structures after 14C-donepezil Administration to Long-Evans Rats.