jonathan hadgraft majella lane
TRANSCRIPT
Jonathan Hadgraft&
Majella Lane
The School of Pharmacy, University of London
Spectrum on skin
λ 3km 3m 30cm 3mm 0.03mm 300nm 3nm 3pm
radiofrequency mic
row
ave
far i
nfra
red
uv x rays γ rayslog ν / Hz 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20
λ 3km 3m 30cm 3mm 0.03mm 300nm 3nm 3pm
radiofrequency mic
row
ave
far i
nfra
red
uv x rays γ rayslog ν / Hz 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20
NMR ESR IR neutrons
λ 3km 3m 30cm 3mm 0.03mm 300nm 3nm 3pm
radiofrequency mic
row
ave
far i
nfra
red
uv x rays γ rayslog ν / Hz 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20
Skin structure
transcellular intercellular
follicular eccrine
Major barrier is in stratum corneum (15 μm thick)
Role of lipids
Corneodesmosomes
Composition & structure of intercellular channels
ceramides (50%) cholesteryl sulphate (5%)cholesterol (25%) free fatty acids (15%)
Michaels et al. 1975
Albery & Hadgraft
Elias
Boddé
Potts & Francoeur
Talreja et al.
Boddé H. et al Int. J. Pharm. 53 (1989) 13-24
Lars Norlen
Cryo-sectioning and cryo-TEM
Freezing 20 ms
-180C
50 – 100 nm thick vitreous section
No cryoprotectants
Hydrogen bonding with ceramides
NO
NH
O
HO
HO
O
HO
HO
HO
NH
HO
NH
O
HOHO
HO
O
HO
HO
HO
ON
O
O
NH -0.41
-0.41-0.42
Hadgraft, J. et al. Int. J. Pharm. (1997) 141, 17-25Gay, C.L. et al. (1989) Int J. Pharm. 49, 39-45
esr
neutron scattering& monolayers
Biophysical techniques
• Infra red• Diffusion studies• Imaging• Diagnosis
• NMR• OTTER• TEWL• MS
Fourier Transform Infra Red
from
ir
sour
ce
to detector
Zn Se crystalmembrane
saturated solution
Diffusion studies
40030020010000
1
2
3
4
5
controlAzone
time (mins)
peak
are
a
120080040000
10
20
30Transcutol: water (50:50)control
time (mins)
peak
are
a
Harrison, J. et al. Pharm. Res. (1996) 13, 542-546
ATR FTIR benzoic acid – octanol:silicone membrane
0
4
8
12
0 1 2 3 4 5 6 7Time (hours)
C=O
pea
k ar
ea pre-treatmentno pre-treatment
Dias, Hadgraft, Raghavan & Tetteh. J. Pharm. Sci. 93 (2004) 186-196
Something for nothing:
InSight
chemometrics
Dias, Hadgraft, Raghavan & Tetteh. J. Pharm. Sci. 93 (2004) 186-196
Russeau
Octanol
Water vapour
Silicone membrane
Benzoic acid
0
4
8
12
0 1 2 3 4 5 6 7Time (hours)
C=O
pea
k ar
ea pre-treatmentno pre-treatment
Software enables separation of methyl and ethyl paraben
-0.5
1.5
3.5
5.5
7.5
9.5
0 100 200 300 400 500 600
Time (min)
CN
Abs
orba
nce
CNP in water
CNP in 5050 Pgwater
CNP in wet PGL
McAuley, Lane
0
0.5
1
1.5
2
0 5 10 15 20 25 30Time (mins)
CN p
eak
abso
rban
ce (A
U) Propylene glycolPEG 400IPMIPIS
Silicone membrane: pools?
Kazarian, McAuley, Lad, Lane
ipm
ipm21 h
pg
Profiles analysed using Scientist and solutions to Fick’s Laws, modelling
Infra red imaging: chemometrics
Kazarian
50 x 50 µm
Sampling the skin: tape stripping
Determination of drug concentration in the stratum corneum (SC) by sequential removal of thin layers of SC at the same site with adhesive tape.
Guy et al.
Industrial – University collaboration
Distribution profile of active across the stratum corneum (SC)
Cx
x/H
AUC
Measure drug concentration profile as a function of position in the SCRequired: (i) amount on each strip, (ii) penetration depth into SC
Evaluation of the rate and extent of active penetration into the stratum corneum - the rate-determining barrier to skin permeation.
How much?
How fast?
Howfar?
Guy et al.
Wavenumbers (cm-1)
0.05
0.10
0.15
0.20
0.25
0.30
0.35
0.40
0.45
Abs
orba
nce
1000 2000 3000 4000
Amide II
Amide I
C=O
C-H stretching symmetric
C-H stretching asymmetric
O-H bending
Lipid extraction – lipid disorderPeak height (area) Peak shift
Dias, Guy, Hadgraft. Lane
Lipid extraction (peak area)
• Both D-octanol and D-hexanol extract the lipids after 55 min of exposure
• D-decanol does not extract the SC lipids
55 min
TS
0
0.2
0.4
0.6
0.8
1
1.2
-2 0 2 4 6 8
norm
alis
ed C
-H p
eak
area
d-decanolcontrold-octanold-hexanol
initial
30 min Stratum corneum depth (μm)
Dias, Guy, Hadgraft. Lane
Lipid disorder (peak shift)
All vehicles produce a blue shift after 30 min of exposureD-decanol disordering effect is maintained for 55 min and in ~2 μm of the SC.
initial
30 min55 min
TS
Stratum corneum depth (μm)
-8
-6
-4
-2
0
2
4
6
8
10
-2 0 2 4 6 8
C-H
pea
k fre
quen
cy s
hift
(cm
-1) control
d-hexanold-decanold-octanol
Dias, Guy, Hadgraft. Lane
-8-6-4-202468
10
0 0.2 0.4 0.6 0.8 1 1.2solvent uptake
C-H
2 asy
mm
etric
str
etch
ing
freq
uenc
y sh
ift (c
m-1
)
volunteer 1
volunteer 2
volunteer 3
volunteer 4
volunteer 5
volunteer 6
volunteer 7
volunteer 8
Solvent uptake (peak area) and lipid disorder (peak shift)
Relationship between the solvent uptake (normalised C-D peak area) and the frequency shift for each volunteer, after exposure to D-decanol for 30 min, 55 min and tape stripping.
Dias, Guy, Hadgraft. Lane
Diagnostics?Psoriasis UVA treatment
Pre-treatmentPeak areas
• C-H asymmetric = 0.07• C-H symmetric = 0.03
Post-treatmentPeak areas
• C-H asymmetric = 0.18• C-H symmetric = 0.07
0.06
0.08
0.10
0.12
0.14
0.16
0.18
0.20
0.22
0.24
0.26
0.28
0.30
0.32
0.34
0.36
0.38
0.40
Abs
orba
nce
1000 1500 2000 2500 3000 3500 Wavenumbers (cm-1)
0.06
0.08
0.10
0.12
0.14
0.16
0.18
0.20
0.22
0.24
0.26
0.28
0.30
0.32
0.34
Abs
orba
nce
1000 1500 2000 2500 3000 3500 Wavenumbers (cm-1)
Watkinson & Burgess 2002.
Clinical dosing: 2 mg/cm2
dynamic
Skin lipids 20% volume: limited solubility capacity
20 μm
In vitro experiments difficult to mimic dose
*
What does solvent deposited solid chemical look like on skin surface?
10 μ g/cm2 4-cyanophenol in acetone
200 μm
*
Environmental Scanning ElectronMicrographs (ESEM)
No deposited chemicalBunge
contact no contact
no contact
Bunge
Particle size and contact with intercellular channels
Permeation of propylene glycol and drug: effect of the amount of gel applied
0
200
400
600
800
1000
1200
1400
0 2 4 6 8 10 12 14 16 18 20 22 24
Time (hours)
Flux
(ng/
cm2/
hr)
0
50
100
150
200
250
300
350
400
Flux
PG
(µg/
cm2/
hr)
Drug: 10mg/cm2 Drug: 40mg/cm2 PG: 10mg/cm2 PG: 40mg/cm2
Trottet et al. Int. J. Pharm. 274 (2004) 213-219
Mass spectroscopy
Royal Society fellow Dr Simona FranceseMalcolm Clench SHU
GARField - a magnet for planar samples
P. M. Glover, P. S. Aptaker, J. R. Bowler, E. Ciampi, P. J. McDonald J. Magn. Reson. (1996) 139, 90.
MagnetPole
Skin
RF Sensor CoilGlass slide
B0
Gy B1
Marker tape
Bo : Magnetic field (0.7 T)
Gy : Field Gradient (17 T/m)
B1 : Radio Frequency field
Fourier Transform gives 1D
projection
0
100000
200000
300000
400000
500000
600000
350 400 450 500
Position (μm)
Am
plitu
de
17 min51 min136 min238 min340 min493 min
sensorGlass Slide
Profile directionSkin
Skin dehydration – in vitro
M Dias, J Hadgraft, P M Glover and P J McDonald, J. Phys. D: Appl. Phys. (2003) 36 364
Comparison with imaging studies
Chan & Kazarian
Time course of kinetics similar
In vivo –lower arm & hand
OTTER
Imhof, London South Bank University
Air
Sample
Pulsed laser excitation
Infra red emission signal
Opto Thermal Transient Emitted Radiation
Glycerol Concentration
0
2
4
6
8
10
12
14
16
18
20
0 2 4 6 8 10 12 14
Depth [um]
Con
cent
ratio
n [a
.u.]
Control5min8min10min
Permeation into nails in vivo
Nail hydration profile
0
5
10
15
20
25
0 5 10 15
Depth [um]C
once
ntra
tion
[a.u
.]
Left ThumbNailRight ThumbNail
Hirata, Imhof, Xiao, Zheng, McAuley, Lane
Hydration profiles in vivo laser confocal Raman
Cork, Matts et al.
Skin structure
transcellular intercellular
follicular eccrine
Major barrier is in stratum corneum (15 μm thick)
Role of lipids
Corneodesmosomes