15. The Correlation Between Transepidermal Water Loss and Percutaneous Absorption: An Overview
16. Role of Calcium in the Regulation of Skin Barrier Homeostasis
17. Percutaneous Penetration Enhancers: An Overview
18. Tests for Skin Protection: Barrier Effect
19. Electron Paramagnetic Resonance Studies of Skin Lipid Structure
20. Human Skin Buffering Capacity: An Overview
21. Skin pH and Skin Flora
15. The Correlation Between Transepidermal Water Loss and Percutaneous Absorption: An Overview
p 182 , Introduction
Transepidermal water loss TEWL – outward diffusion water ผ่าน skin
– วัด gauge skin’s water barrier fn
– increase TEWL – บอกถึง impair water barrier
– วัดโดยดู allow parametric evaluation – effect of barrier creams against irritants and characterization of skin fn – ใน clinical dermatitis , irritant , allergic patch reaction
evaporimeter – determine TEWL – วัด pressure gradient of boundary layer – จาก water gradient ระหว่าง skin surface – ambient air
– effect anatomical site – sweating , skin surface temp , inter- and intraindividual variation ,
– air convection , ambient air temp , humidity , instrument-related variable
ถือว่า evaporimeter เป็น reproducible ทั้งใน vitro and vivo
Percutaneous Absorption
rate absorption topically applied chemical ผ่าน skin
compound’s absorption rate – ส. ในการประเมิน effectiveness and/or potential toxicity of topically applied compound
topical formulation ถูกใช้กับ disease skin หลายๆอย่าง , ส่วน integrity of permeability barrier ยังสงสัย
– dose absorb into body – vary
rate of absorption in vivo ผ่าน SC(stratum corneum) – ไม่สามารถ described by – zero-ro first-order mathematical rate equation
– เพราะ SC เป็นcomplex system variable ใน penetration properties
percutaneous absorption rate variation 3 category – namely , methodology (รวม effect of application time , method of measurement , physicochemical properties of topical compound)
– interindividual variation – รวมถึง effect of skin condition , age individual ,blood flow
16. Role of Calcium in the Regulation of Skin Barrier Homeostasis
17. Percutaneous Penetration Enhancers: An Overview
18. Tests for Skin Protection: Barrier Effect
19. Electron Paramagnetic Resonance Studies of Skin Lipid Structure
20. Human Skin Buffering Capacity: An Overview
21. Skin pH and Skin Flora