Increased permeability for polyethylene glycols through skin compromised by sodium lauryl sulphate

Abstract

In this in vivo human study we assessed the influence of skin damage by sodium lauryl sulphate (SLS) on percutaneous penetration of polyethylene glycols (PEGs) of different molecular weights (MW). Percutaneous penetration of PEGs was determined using tape stripping of the stratum corneum (SC). The forearm skin of volunteers was pretreated with 5% w/w SLS for 4 h, and 24 h later patches with PEGs were applied for 6 h. The penetration parameters were deduced by data regression to Fick's law for unsteady-state diffusion. The trans-epidermal water loss (TEWL) increased after SLS treatment from 6.3 +/- 2.1 to 17.9 +/- 8.7 g/m(2)/h. The diffusion coefficient for all PEGs was increased in the SLS-damaged skin. The increase was smaller for higher MW. In addition, the partition coefficient of PEGs between SC and water was larger in the SLS-compromised skin and showed a tendency to increase with MW. The permeability coefficient decreased gradually with increasing MW of PEGs in both control and SLS-compromised skin. SLS caused a threefold increase in the permeability coefficient for all MWs ranging in control skin from 0.34 to 0.70 x 10(-5) cm/h and in the SLS-compromised skin from 1.20 to 2.09 x 10(-5) cm/h for MW of 590-282 Da. The results of this study show the deleterious effect of SLS on the skin barrier for hydrophilic PEGs. A defective skin barrier will facilitate absorption of other chemicals and local skin effects.

Enhancement of optical skin clearing efficacy using a microneedle roller

“…Such methods include tape stripping, ultrasound, microneedles, iontophoresis, electroporation, microdermabrasion, laser ablation, needle-free injection guns, and photomechanical and chemical waves. [12][13][14][15][16][17][18][19][20] We propose a new physical method to enhance the efficacy of optical skin clearing by an OCA, glycerol. The method uses a microneedle roller that is ISO 9001:2000 approved and widely and safely used in dermatology.…”

An in vitro Skin Penetration Model for Compromised Skin: Estimating Penetration of Polyethylene Glycol [¹⁴C]-PEG-7 Phosphate

“…For small-MW PEGs (282-590 Da) Jakasa et al [12] demonstrated a threefold increase in the permeability coefficient in SLS-treated skin [5% sodium lauryl sulfate for 4 h (forearm skin), and 24 h later patched with PEGs for 6 h] compared to untreated skin. The permeability coefficient for all MWs in untreated skin ranged from 0.34 to 0.70 × 10 -5 cm/h and in sodium lauryl sulfate-damaged skin ranged from 1.20 to 2.09 × 10 -5 cm/h for MW of 590-282 Da [12]. Thus, even compounds having a high MW can have a potentially higher bioavailability when exposed to compromised versus intact skin.…”

“…Further, increased penetration was demonstrated for autopsy premature skin when compared to adult and full-term infant (38-40 weeks gestation) skin samples [23]. The degree of impact of damaged skin on dermal penetration rate is chemical-specific, with some chemicals having an increased and others having a comparable skin penetration to that of intact skin [11,12,22]. Substances with MW >500 Da are generally accepted to penetrate slowly through intact skin with negligible penetration for molecules with a MW >1,000 Da in intact adult skin [5].…”

“…The total amount penetrated was approximately 1% of the applied dose for the high-MW oligomer (MW 1,074 Da; TEWL: 30-40 g/m 2 /h) and approximately 7% for the smallest PEG (MW 238 Da; TEWL: 30-40 g/m 2 /h) used in the test [11]. For small-MW PEGs (282-590 Da) Jakasa et al [12] demonstrated a threefold increase in the permeability coefficient in SLS-treated skin [5% sodium lauryl sulfate for 4 h (forearm skin), and 24 h later patched with PEGs for 6 h] compared to untreated skin. The permeability coefficient for all MWs in untreated skin ranged from 0.34 to 0.70 × 10 -5 cm/h and in sodium lauryl sulfate-damaged skin ranged from 1.20 to 2.09 × 10 -5 cm/h for MW of 590-282 Da [12].…”

“…TEWL measures the steady-state water flux that passes through the epidermal layer to the surrounding atmosphere via diffusion and evaporation [9,10]. TEWL has been used as an indicator of skin integrity deficiencies, like damage from chemical or physical irritants or changes under occlusive conditions [11,12,13,14]. …”