ETRLab

Electro Therapy Research Laboratory for Tissue Growth & Repair

Jae Hyoung Lee Wonkwang Health Science College

[email protected]

http://etgr.wkhc.ac.kr

ETRLab

SECTION . IONTOPHORESIS

학습목표

1.

이온도입치료를 정의한다

. 2.

이온도입의 물리화학적 특성을 설명한다

. 3.

이온도입의 생리학적 특성을 설명한다

. 4.

약물의 물리화학적 특성을 설명한다

. 5.

약물의 극성을 열거한다

. 6.

약물의 종류에 따른 효과와 치료효과를 설명한다

. 7.

약물의 종류에 따른 적응증을 설명한다

. 8.

약물의 종류에 따른 부작용과 금기증을 설명한다

. 9.

이온도입치료의 금기증을 설명한다

. ETRLab

이온도입치료

(iontophoresis, ion transfer)

1. Definition

Iontophoresis is a process which allows for enhanced transdermal drug delivery by use of an applied current through the skin.

Iontophoresis is of great interest because it provides a safe, economical and convenient way to administer charged or neutral drugs in a controlled manner through the skin. Iontophoresis uses mild DC electrical current (maximum = 4.0

milliamps) to transport the positively or negatively charged ions from the drug solution into the patient's tissue.

전류

(

직류

,

고전압맥동전류

,

교류

)

를 이용해서 약물 이온을 피부 또는 점막을 통해 신체의 안으로 침투시키는 치료방법

*

전류의 흐르는 방향과 크기가 변하지 않는 전류

이온도입치료

(iontophoresis, ion transfer)

Ion transfer -

전류에 의해 이온이 이동하는 것

Iontophoresis cataphoresis -

약물이온을 피부 또는 점막을 통해 조직으로 침투시키는 것 전리되지 않는 콜로이드 분자를 음극쪽으로 이동시키는 것

Another name for electrophoresis Phonophoresis -

초음파를 이용하여 약물을 피하조직으로 침투시키는 것

Electrophoresis – the motion of charged particles in a colloid under the influence of an applied electric field ion (to go, from Gk. Ienai) + top/o (place, from Latin topos) + phor/o (to bear, from Gk. Phoros) + -esis (noun suffix) Giovanni Francesco Pavati (1748, 1749, 1750) Stephane Leduc (1908)

약물전달체계

(Drug Delivery System, DDS)

DDS

는 약물의 방출속도 제어

,

특정 신체 부위로의 표적화

,

생체내 신호 감지에 따른 약물 방출 등을 통해 치료효과의 극대화

(

efficacy

),

부작 용의 최소화

(

safety

),

및 환자의 복약 편의성

(

patient compliance

)

을 향상시킨 새로운 약물 투여 체계이다

.

약물은 적용에 편리하고 효과가 최적으로 발현될 수 있는 체계로 만들어 진 후 경구

,

흡입

,

주사

,

경점막

,

경피 등 여러 경로로 생체에 투여된다

. 1960s 1970s – 1980s -

좌약 비강 및 구강투여

1990s -

주사 및 주입 피부

,

폐 및 구강 전달 방법 선호

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DDS

의 종류

1)

(1) (2) (3) (4)

(5)

흡수촉진형 약물전달체계

흡수촉진제 이용

: enhancer

이용 복합체 이용

이온도입

:

복합체

(complex)

(iontophoresis)

나 전구물질 생체 필수물질의 수송계 새로운 투여경로

(

구강

, (transporter)

안구

,

질

,

직장

,

이용 피부

, (prodrug)

폐 등

)

전기천공

(electroperporation)

초음파영동

(phonophoresis)

사용

2)

약효지속형 약물전달체계

3)

표적지향적 약물전달체계

리포좀

,

에멀젼

,

(targeting DDS)

마이크로스피어 등 미립자 운반체 이용

4)

인공지능 약물전달체계

(intelligent DDS)

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3.

경피약물전달체계

(transdermal drug delivery system, TDDS) 1)

경피약물전달체계의 종류

(1) (2) (3) (4) (5) (6)

플라스터체계

(plaster system)

막제어체계

(membrane controlled system)

점착분산막체계

(adhesive dispersion-type system)

경사 점착분산막체계

(gradient adhesive dispersion-type system)

기질확산조절체계

(matrix diffusion controlled system)

미세저류조절체계

(microreservoir dissolution controlled system) ETRLab

Advantages of Transdermal Drug Delivery

1)

간 초회통과효과

(first-pass effect)

를 받지 않는다

.

따라서 생체이용율

(bioavailability)

을 높일 수 있다

.

2)

위장관 분해

(gastrointestinal degradation)

과정을 거치지 않는다

.

3)

투여속도를 조절할 수 있어 일정속도로 장시간 지속적으로 약물을 투 여할 수 있다

.

4)

환자의 복약 편의성

(patient compliance)

이 좋다

.

5)

약물 투여횟수를 줄일 수 있다

.

6)

약물 투여 중 투여를 중단할 수 있다

.

7)

주사 및 경구 투여의 단점을 보완하고 부작용을 감소시키고 치료효과 를 증진한다

.

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SECTION II. ELECTROPHYSIOLOGY

1. Percutaneous Absorption - rate of penetration proportional to lipophilicity.

• Stratum corneum: THE MAJOR BARRIER Penetration by passive diffusion Polar (hydrophilic) substances diffuse through the outer surface of protein filaments of the hydrated stratum corneum (H 2 0 content permeability to polar substances) Nonpolar (lipophilic) substances diffuse through the nonaqueous lipid matrix of the cells & extracellular space. Exposure to highly lipophilic substances can increase penetrability of co-exposed hydrophilic substances.

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SECTION II. ELECTROPHYSIOLOGY

1. Percutaneous Absorption • Viable epidermis & dermis : Much more easily penetrated. Toxicants reach vasculature & lymphatics in dermis.

1) Through epidermal appendages (ex. hair follicles, sweat glands) occurs, but it's relatively minor due to relative surface area (i.e. 0.1% of total body surface).

2) Through cuts & abrasions relative to degree of exposure of the broken surfaces. (Can play a major role if exposed to some pathogens - i.e. herpes, AIDS).

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SECTION II. ELECTROPHYSIOLOGY

1. Percutaneous Absorption • Factors affecting absorption: Skin: applied dose time of exposure surface area of exposure efficiency of absorption (relative to concentration of applied substance) physical integrity of stratum corneum regional variation (scrotum thinnest  soles of feet, palm are thickest) degree of hydration temperature (for lipophilic compounds) sweat (can dissolve toxicants from solids, making them bioavailable)

ETRLab

SECTION II. ELECTROPHYSIOLOGY

1. Percutaneous Absorption • Factors affecting absorption: Vehicle: lipophilicity may affect pH (affecting ionization) may damage skin presence of ionic surfactants permeability Substance: water permeability relatively low ditto simple polar substances methylene groups permeability (=CH 2 ) lipophilicity damaging substances effects/permeability (actually may lipid content of skin) TRUE GASES penetrate skin well Vapor phase substances - penetration varies w/nature of substance, still may penetrate due to lipophilicity, etc.

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SECTION II. ELECTROPHYSIOLOGY Table. Regional Variation in Water Permeability at 30℃ Water Stratum Corneum Permeation Rate Thickness Diffusivity Time Lag Skin Region (mg/

㎠

/h) (

㎝

x10 4 ) (

㎠

//sec x 10 10 ) (min) Abdomen 0.34 15.0 6.0 11 Forearm, Volar 0.31 16.0 5.9 12 Back 0.29 10.5 3.5 9 Forehead 0.85 13.0 12.9 4 Scrotum 1.70 5.0 7.4 1 Hand, Dorsum 0.56 49.0 32.3 22 Palm 1.14 400 535.0 83 Sole 3.90 600 930 106 Water Permeation Rate (J), Stratum Corneum Thickness (ℓ), Diffusivity (D) are relayed through Frick’s Law of Diffusion as follow: DΔC J = ΔC is concentration difference of wateracross the stratum corneum.

ℓ

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4. Stratum corneum 3. stratum granulosum, 2. Stratum spinosum 1. basal cell layer Fig. Photomicrograph (x2000) and transmission electron micrograph (x3000) of human epidermis. 1. basal cell layer, 2. Stratum spinosum, 3, stratum granulosum, 4. Stratum corneum. M is melanocyte, L is Langerhan’s cell.

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Fig. An electron micrograph of the full thickness of stratum corneum from human forearm. The lower most cell shows some of changes associated with transitional cell. The uppermost cell is only loosely attached to the underlying cell. Note desmosome (O) and relatively dense cytoplasm of the stratum corneum cells. The light spaces between the cell are artifacts of extraction of intercelluler materials. (x12,000) ETRLab

Structure and Composition of Skin Table. Thickness and Number of Cell Layers in Stratum Corneum Thickness (

㎛

) Number of Cell Layers Mean Range Mean Ranges Abdomen 8.2 6.9 - 9.8 18 15 - 20.9

Forearm Flexor 12.9 8.1 - 16.2 21.6 16.7 - 30 Thigh 10.9 7.7 - 15.3 19.3 14.3 - 22.7

Back 9.4 8.2 - 11.3 15.8 14 - 21.1

Holbrook and Odland (1974). Epidermis : 30-1000

㎛

Thin skin : 75- 150

㎛

(0.03-1 mm) (0.075-0.15 mm) Thick skin : 400-600

㎛

(0.4-0.6 mm) One new cell migrate from the basal layer per day 15-30 corneocytes in the tissue, SC is completely replaced every 15-30 days ETRLab

Physical Barrier of Skin Brick & Mortar Model Brick : Corneocyte envelope (CE) Motar : Lipid (lamellar sheet)

Epidermis : 0.03-1 mm Thin skin : 0.075-0.15 mm Thick skin : 0.4-0.6 mm

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Fig. Stratum corneum from the posterior inferior iliac region of a human. (x4050).

Intercellular lipid is clearly distinguishable from the intercellular material. The lipid bilayers , which cement the structure together into a coherent membrane, consist of triglycerides, free fatty acids, free sterols, and ceramides .

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Lipid components rearrangement in the lipid bilayers between stratum corneum.

Acts as a permeability barrier.

Fig. Diagram summarizing concepts of intercellular lipid bilayer from the lamellar granule (lamellar body). (J. Invst. Dermatol. 73:333-348, 1979) ETRLab

Formation of the epidermal lipids The precursors of the epidermal lipids are formed in the Golgi apparatus

②

of the keratinocytes in the upper layers of stratum spinosum . Then the lipids in microscopically small granules are slacked membrane-enclosed vacuoles ( Odland bodies

①

).

In the upper layer of the stratum granulosum

④

into the intercellular space by exocytosis

③

.

the Odland bodies

①

emptied the lipids The epidermal lipids form the cement that holds the corneocyte

⑤

together ( (brick and mortar model).

Fig. Schematic procedures of formation of the epidermal lipids. ETRLab

Fig. Scanning electron microscope image of a freeze-dried section of the stratum corneum.

1. Corneocytes, 2. Intercellular space, partially filled with epidermal lipids.

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Composition of the epidermal lipids * Epidermal lipids consists : mainly of phospolipids. During differentiation (cornification) of the keratinocytes they are degraded. Composition of the Barrier Lipids highly organised, multilamellar bilayers.

Ceramides, Cholesterol and Free fatty acids predominate in the stratum corneum.

Fig. Normal skin barrier. 1. Ceramides, 2. Cholesterol, 3. Free fatty acid.

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SECTION II. ELECTROPHYSIOLOGY Table. Chemical Composition of Some Purified Membranes (Wt/%) Membrane Lipid Protein Carbohydrate Myelin 79 18 3 Human erythrocyte 43 49 8 Mouse liver 52 44 4 Ameba 42 54 4 Mitochondrial inner 24 76 0 membrane Guidoti G, Ann Rev Biochem 41:731, 1972.

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SECTION II. ELECTROPHYSIOLOGY Permeability of Human Skin Table. Variation in Lipid Composition during Epidermal Differentiation and Cornification (Wt/%) Strata Fraction Stratum Basale/Spinosum Strata Granolusum Stratum Corneum Polar lipids 44.5

±

3.4

25.3

±

2.6 4.9

±

1.6

Cholesterol sulfate 2.6

±

3.4 5.5

±

1.3 1.5

±

0.2

Neutral lipids 44.7

±

4.5

58.5

±

2.8 74.8

±

5.6

Free steroid 11.2

±

2.7 11.5

±

1.1 14.0

±

1.1

Free fatty acids 7.0

±

2.1 9.2

±

1.5 19.3

±

3.7

Triglycerides 12.4

±

2.9 24.7

±

4.0 25.2

±

4.6

Sterol/wax esters 5.3

±

1.3 4.7

±

0.7 5.4

±

0.9

Squalene 4.9

±

1.1 4.6

±

1.0 4.8

±

2.0

n-Alkanes 3.9

±

0.3 3.8

±

0.8 6.1

±

2.6

Sphingolipids 7.3

±

1.0

11.7

±

2.7 18.1

±

2.8

Glucosylceramides 3.5

±

0.3 5.3

±

0.2 Trace Ceramides 3.8

±

0.2 6.4

±

0.3 18.1

±

0.4 Total 99.1 101.0 99.3

Elias (1983). SB/S; n=5, SG; n=7, SC; n=4.

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Desmosome and Tight Junction

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Fig. Desmosomes. Thin section is from bovine tongue. Linear array of desmosomes along the junction of a pair of cells. Keratin Fs appear to attach to intracellular side of the desmosomes. (x40000). ETRLab

Tight Junction

Fig. 4. Immunofluorescence staining of occludin (A) and schematic structure of tight junction and TJ-related structures (B).

Occludin was expressed in the granular layer. The lamellated junction (LJ) and sandwich junction (SJ) are located between the keratinocyte in the granular layer (St.G), and connecting the two bilayer membrane of keratinocytes between the demosom (D).

From Morita and Miyachi, 2003.

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Tight Junction ETRLab

Figure 1 Medium-magnification transmission electron micrographs of the cytoplasmic space at the midportion of the viable part of human epidermis (A,B). (A) Cryo-electron micrograph of vitreous sections. (B) Conventional electron micrograph of resin-embedded sections. In the vitreous cryo-fixed epidermis (A), cellular as well as intercellular space appears densely packed with organic material, while in the conventionally fixed epidermis (B), the distribution of biomaterial is characteristically inhomogeneous. Loss of biomaterial appears to have taken place in (B). In (B), the loose tonofilament (TF) networks omnipresent in (A) are aggregated into distinct bundles. Furthermore, the rich variety of interfilament membrane structures, organelles (black asterisk) and 'polyribosome-like complexes' (open white arrows) present in (A), are, for the major part, absent in (B). Open white arrows (A): 'polyribosome-like complexes' (strongly folded rough endoplasmatic reticulum (cubic like?) with a small ( 25 nm) lattice parameter?); black asterisk (A): different 'organelles'; D: desmosome (A); black asterisk (B): artefactual 'empty cytoplasmic space'; white asterisk (B): organelle remnants. Section thickness 100 nm (A). Scale bars 100 nm (A,B). ETRLab

Figure 2 High-magnification electron micrographs of 'amorphous' keratin intermediate filaments (IF) at the midportion of the cornified part of human epidermis. (A) Cryo-electron micrograph of vitreous section. (B) Conventional electron micrograph of resin-embedded section. In (B), keratin IFs appear as 7-8 nm wide electron-lucent spots embedded in an electron-dense matrix, while in (A), they appear as 7.8 nm wide electron-dense structures with an interfilament distance of 16 nm, embedded in a comparatively electron lucent matrix. The subfilamentous molecular architecture cannot be distinguished in (B), while in (A), it appears as groups of electron-dense spots surrounding a central dense dot. Moreover, in the dehydrated embedded sample (B), the IFs are clustered together, with consequent diminished interfilamentous distances, when compared to the fully hydrated native sample (A). In (A), the complete tissue is homogeneously preserved. Section thickness 50 nm (A). Scale bars 50 nm (A,B). (B) Reprinted from [95], with permission from the Academic Press Inc., New York.

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Figure 3. High-resolution transmission electron micrographs of multilamellar membrane structures in the intercellular space of the cornified part of human epidermis. (A) Cryo-electron micrograph of vitreous section. (B,C) Conventional electron micrographs of resin-embedded sections. The cell plasma membranes are not visible in (B,C) while they appear as 3.8 nm wide bilayers in (A) (open white arrow). A 16-nm broad zone of electron-dense material, the cornified cell envelope (white asterisk), is directly apposed to the cytoplasmic side of the bilayer plasma membranes in the native sample (A) (open white arrow). Scale bar 50 nm (A). Scale bars 25 nm (B,C) adapted from measures given in Swartzendruber et al.[29]. (B,C) Reprinted from Swartzendruber et al.[29], with permission from Blackwell Science Publications.

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Figure

4.

Medium-magnification electron micrographs of the straum granulosum/stratum corneum interface. (A) Cryo electron micrograph of vitreous section. (B) Conventional electron micrograph of resin-embedded section. A new 'organelle or branched tubular structure' (A, open white arrows), corresponding to 'lamellar bodies' of classical chemical fixation electron micrographs (B, MG), and a new 'ribosome complex-like structure' (A, open black arrows; cf. Fig. 1, open white arrows), not preserved in classical electron micrographs (B), were both omnipresent at apparent active sites of skin barrier formation (A). Further, conventional chemical fixation electron micrographs of the stratum granulosum/stratum corneum interface characteristically shows large artefactual 'empty' areas (black asterisk) and artefactual aggregation of tonofilament structures (TF) into distinct bundles (B). T: transition cell; SC1: lowermost cornified cell; black and white asterisk: multifolded or multivesicular membrane complex; TF: tonofilaments; MG: lamellar body within stratum granulosum cell (B); EMG: lamellar body in the intercellular space (B); CE: cornified envelope. Scale bar 200 nm (A). (A) Adapted from Norlén

et al.

[16] with permission from Blackwell Science Publications. (B) Adapted from Stenn [96, p. 577] with permission from the Macmillan Press Ltd.

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Fig. Photomicrograph of alkali-swollen human stratum corneum showing orderly stacking and interdigitation of cornified cell (x500).

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SECTION II. ELECTROPHYSIOLOGY Cell Membrane (Plasma Membrane, Plasmalemma) Lipid Bilayer Integral Protein ETRLab

Cell and Cell Membrane @ Stratum Corneum Brick and Mortar model.

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