Penetrate through human skin

N. Leveque, S. Makki, J. Hadgraft, and P. Humbert. Comparison of Franz cells and microdialysis for assessing salicylic acid penetration through human skin. Int. J. Pharm. 269 323-328 (2004). 

Aungst, B.J., N.J. Rogers, and E. Shefter. 1986. Enhancement of naloxone penetration through human skin in vitro using fatty acids, fatty alcohols, surfactants, sulfoxides and amides. Int J Pharm 33 2256. 

Chilcott et al. reported the in vitro measurements of S-labelled SM penetration through human skin (heat-separated epidermal membranes and full thickness skin) using Franz type static diffusion cells at 30-32 °C. The measurements were made after exposing the skin surface to pure SM liquid (finite, 10 pi, and infinite, 20 pi, doses) under occluded and unoccluded conditions and after exposure to saturated SM vapour. 

The penetration of 1,4-dioxane through human skin is poor. In-vitro studies show... 

Many studies have employed phospholipids as liposomes (vesicles) to transport drugs into and through human skin. However, a few investigations have also employed phospholipids in a nonvesicular form as penetration enhancers. For example, 1% phosphatidylcholine in PG, a concentration at which liposomes would not form, enhanced theophylline penetration through hairless mouse skin [64]. Similarly, indomethacin flux was enhanced through rat skin by the same phospholipid and hydrogenated soybean phospholipids increased diclofenac permeation through rat skin in vivo. 

Cal, K., S. Janicki, and M. Sznitowska. 2001. In vitro studies on penetration of terpenes from matrix-type transdermal systems through human skin. Int J Pharm 224 81. 

Blank IH, McAuliffe DJ. 1985. Penetration of benzene through human skin. J Invest Dermatol 85 522-526. 

Barry, B. W. and Bennett, S. L. Effect of penetration enhancers on the permeation of mannitol, hydrocortisone and progesterone through human skin. Journal of Pharmacy and Pharmacology 39(7) 535-546, 1987. 

Uranium can enter the human body through inhalation, ingestion, or penetration through the skin. Measurement of the quantifies of uranium in the body can be performed by two primary methods, in vivo measurements and in vitro measurements. These types of measurements are called bioassays. In vivo techniques measure the quantifies of internally deposited uranium directly using a whole body counter while in vitro techniques permit estimation of internally deposited uranium by analysis of body fluids, excreta, or (in rare instances) tissues obtained through biopsy or postmortem tissue sectioning (NCRP 1987) (USUTR 1999). Some of these analytical methods are summarized in Table 6-1. 

Franz, T.J. Lehman, P.A. Franz, S.F. North-Root, H. Demetrulias, J.L. Kelling, C.K. Moloney, S.J. Gettings, S.D. Percutaneous penetration of V-nitroso-diethanolamine through human skin (in vitro) comparison of finite and infinite dose apphcation from cosmetic vehicles. Fundam. Appl. Toxicol. 1993, 21, 213-221. 

Walters, K.A. Brain, K.R. Howes, D. James, V.J. Kraus, A.L. Teetsel, N.M. Toulon, M. Watkinson, A.C. Gettings, S.D. Percutaneous penetration of octyl salicylate from representative sunscreen formulations through human skin in vitro. Fd. Chem. Toxicol. 1997, 35, 1219-1225. 

Figure 9.22 Drug penetration-time profile for an idealised drug diffusing through human skin once steady-state diffusion occurs Q, can be obtained using equation (9.14) where t= (time elapsed - r).

White spirit, a mixture of mostly aliphatic (lipophilic) hydrocarbons, enhanced the penetration of the pesticide lindane through human skin. 14 ... 

Before launching wound study, the ability of ATP-vesicles to penetrate the tissue was tested in skin penetration. The rat skin, which is known to have similar permeability characteristics as those of humans (19), was mounted in the FDC-6 Franz Diffusion Cells (26-28). ATP-vesicles or free ATP solution was placed in the donor dome and the receiving chamber was filled with neutral buffer. ATP, ADP, AMP and their metabolites were measured by HPLC using a modified technique described previously (29-31) in the two chambers at 2, 4, and 24 h and the contents were compared to obtain the permeability ratio. The result indicated that the ATP-vesicles dramatically increased nucleotide penetration through the skin (dermis and epidermis) by 10-20-fold (N=9, Fig. 5). 

There are few published data on the percutaneous absorption of sunscreens through human skin (239,242-248). Most of the information came from in vitro penetration studies or by estimation from the amount recovered in the stratum corneum after tape stripping. The rationale for using the latter method (often referred to as the "reservoir technique") is based on the finding by Treffel and Gabard (248)that a linear relationship exists between the drug concentration in the stratum corneum and its in vivo percutaneous absorption. 

Strontium can enter the human body through inhalation, ingestion, or penetration through the skin. Measurement of the quantities of radiostrontium in the body can be performed by two primary methods, in vivo measurements and in vitro measurements. These types of measurements are called bioassays. 

Figure 14.6 Influence of the penetration enhancers SEPA and Azone on the permeation of indomethacin through human skin in vitro. The permeant and enhancers were applied in a hydroalcoholic solution (data courtesy of Dr C. M. Samour).

Walters, K. A., K. R. Brain, W. E. Dressier, D. M. Green, D. Howes, V. J. James, C. K. Kelling, A. C. Watkinson, and S. D. Gettings. 1997b. Percutaneous penetration of N-nitroso-N-methyldodecylamine through human skin in vitro Application from cosmetic vehicles. Food Chem. Toxicol. 35 705-712. 

Nakai. J. S., and Chu, 1. (1997). Effect of environmemal condi-tioas on the penetration of benzene through human. skin. J Toxicol. Environ. Health 51, 447- 62. 

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