Comprehensive outlook of in vitro tests for assessing skin irritancy as alternatives to Draize tests

Eun, Hee Chul; Suh, Dae Hun

doi:10.1016/s0923-1811(00)00093-1

Cited by 25 publications

(20 citation statements)

References 67 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…In addition, these studies also show that IR spectroscopic analysis of protein conformation in the SC can be used to predict the irritation response. Such methods provide a superior alternative to cell culture or animal-based methods that are resource-intensive, expensive, and exhibit higher variability (28)(29)(30).…”

Section: Discussionmentioning

confidence: 99%

Design principles of chemical penetration enhancers for transdermal drug delivery

Karande

Jain

Ergun

et al. 2005

Proc. Natl. Acad. Sci. U.S.A.

334

250

View full text Add to dashboard Cite

Chemical penetration enhancers (CPEs) are present in a large number of transdermal, dermatological, and cosmetic products to aid dermal absorption of curatives and aesthetics. This wide spectrum of use is based on only a handful of molecules, the majority of which belong to three to four typical chemical functionalities, sporadically introduced as CPEs in the last 50 years. Using >100 CPEs representing several chemical functionalities, we report on the fundamental mechanisms that determine the barrier disruption potential of CPEs and skin safety in their presence. Fourier transform infrared spectroscopy studies revealed that regardless of their chemical make-up, CPEs perturb the skin barrier via extraction or fluidization of lipid bilayers. Irritation response of CPEs, on the other hand, correlated with the denaturation of stratum corneum proteins, making it feasible to use protein conformation changes to map CPE safety in vitro. Most interestingly, the understanding of underlying molecular forces responsible for CPE safety and potency reveals inherent constraints that limit CPE performance. Reengineering this knowledge back into molecular structure, we designed >300 potential CPEs. These molecules were screened in silico and subsequently tested in vitro for molecular delivery. These molecules significantly broaden the repertoire of CPEs that can aid the design of optimized transdermal, dermatological, and cosmetic formulations in the future. stratum corneum ͉ spectroscopy ͉ skin irritation ͉ lipid C urrently, hypodermic needles are the only available mode for systemic delivery of macromolecular drugs into humans. Transdermal delivery offers an attractive alternative to needlebased drug administration. However, evolved to impede the flux of exogenous molecules, stratum corneum (SC), the topmost layer of the skin, provides a strong barrier to molecular delivery. This is especially problematic for relatively large drugs (molecular mass Ͼ 500 Da), which represent a large majority of active agents for therapeutic applications (1). Over 350 molecules, termed chemical penetration enhancers (CPEs), have been identified to perturb the SC barrier to facilitate molecular delivery. However, incorporation of CPEs into products has been mitigated by safety concerns related to the health of the skin membrane (2-4). Accordingly, overcoming the skin barrier in a safe and effective way still remains the bottleneck of transdermal and topical therapies.Identification of chemicals to increase skin permeability has been an area of high activity in the last three decades (5-7). After an initial rise in the number of CPEs in the 1980s, the active pool of CPEs has reached a plateau in the last decade. In an era where new chemical entities are being discovered at an exponential rate (as indicated by the entries in the Chemical Abstract Service), the plateau in the number of CPE molecules is rather surprising (only 1 in 100,000 known molecules represents a CPE). This anomaly originates from the slow rates of syntheses of CPEs when compar...

show abstract

Section: Discussionmentioning

confidence: 99%

Design principles of chemical penetration enhancers for transdermal drug delivery

Karande

Jain

Ergun

et al. 2005

Proc. Natl. Acad. Sci. U.S.A.

334

250

View full text Add to dashboard Cite

show abstract

“…Testing for skin corrosion or irritation has traditionally been conducted in animals, particularly in rabbits via the Draize test method (4). However, due to increasing concern over animal experimentation and its potential prohibition in the near future (5), alongside the obvious ethical implications of the use of human subjects, in vitro alternatives must now be developed.…”

Section: Introductionmentioning

confidence: 99%

Assessment of the Potential Skin Irritation of Lysine-Derivative Anionic Surfactants Using Mouse Fibroblasts and Human Keratinocytes as An Alternative to Animal Testing

et al. 2004

View full text Add to dashboard Cite

Purpose. The aim of this study was to identify new surfactants with low skin irritant properties for use in pharmaceutical and cosmetic formulations, employing cell culture as an alternative method to in vivo testing. In addition, we sought to establish whether potential cytotoxic properties were related to the size of the counterions bound to the surfactants.Methods. Cytotoxicity was assessed in the mouse fibroblast cell line 3T6, and the human keratinocyte cell line NCTC 2544, using the MTT assay and uptake of the vital dye neutral red 24 h after dosing (NRU).Results. Lysine-derivative surfactants showed higher IC 50 s than did commercial anionic irritant compounds such as sodium dodecyl sulphate, proving to be no more harmful than amphoteric betaines. The aggressiveness of the surfactants depended upon the size of their constituent counterions: surfactants associated with lighter counterions showed a proportionally higher aggressivity than those with heavier ones.Conclusions Synthetic lysine-derivative anionic surfactants are less irritant than commercial surfactants such as sodium dodecyl sulphate and Hexadecyltrimethylammonium bromide and are similar to Betaines. These surfactants may offer promising applications in pharmaceutical and cosmetic preparations, representing a potential alternative to commercial anionic surfactants as a result of their low irritancy potential.

show abstract

“…The monolayer culture is a relatively simple method to use, and there are many reports of this method for evaluating irritancy, including the validation of human or ani- C Human deepidermized dermis (containing basement membrane components) [23] D Substrates containing matrix components Fibroblast-populated collagen gel [24] Fibroblasts grown in a nylon mesh [25] Lyophilized collagen-glycosaminoglycan membranes crosslinked by chemical agents [26] mal tests, which have already been well reviewed [5]. Keratinocytes, which constitute the first level of defense against the environment, are the most widely used cells for skin irritancy tests, and many trials are being done using these cells [6][7][8][9][10].…”

Section: Monolayer Culturementioning

confidence: 99%

“…Observing the morphology of the skin by histology including immunohistochemistry is one of the basic methods. However, measuring cytotoxicity and inflammatory mediators is a more commonly used method as shown in table 1 [5] and table 2 [11][12][13]. Both of these procedures are also applicable to the measurement of skin irritancy using skin explant and threedimensional cultures, which are further mentioned below.…”

Section: Monolayer Culturementioning

confidence: 99%

Alternative Methods for Evaluating Skin Irritation Using Three-Dimensional Cultures

Eun

Nam

2003

Exog Dermatol

Self Cite

View full text Add to dashboard Cite

The Draize test has long been used as a method to evaluate skin irritancy. However, alternative methods have since been developed, in response to pressure from the ever-increasing movement of animal protectionists. Cell culture represents the most promising alternative method, and many trials of various kinds are under way, for example the monolayer culture, skin explant culture and three-dimensional skin equivalent culture. It is quite likely that better-qualified three-dimensional culture systems constitute the final goal in the search for alternative methods to evaluate skin irritancy. However, its effective validation will require not only further large-scale studies, but also the development of superior artificial skin models, with properties more closely resembling those of normal skin. In this review, we focus mainly on the skin equivalent culture method for measuring skin irritancy. Its superiority to other models as well as its problems and limitations are discussed.

show abstract

Comprehensive outlook of in vitro tests for assessing skin irritancy as alternatives to Draize tests

Cited by 25 publications

References 67 publications

Design principles of chemical penetration enhancers for transdermal drug delivery

Design principles of chemical penetration enhancers for transdermal drug delivery

Assessment of the Potential Skin Irritation of Lysine-Derivative Anionic Surfactants Using Mouse Fibroblasts and Human Keratinocytes as An Alternative to Animal Testing

Alternative Methods for Evaluating Skin Irritation Using Three-Dimensional Cultures

Contact Info

Product

Resources

About