51
|
Adler S, Basketter D, Creton S, Pelkonen O, van Benthem J, Zuang V, Andersen KE, Angers-Loustau A, Aptula A, Bal-Price A, Benfenati E, Bernauer U, Bessems J, Bois FY, Boobis A, Brandon E, Bremer S, Broschard T, Casati S, Coecke S, Corvi R, Cronin M, Daston G, Dekant W, Felter S, Grignard E, Gundert-Remy U, Heinonen T, Kimber I, Kleinjans J, Komulainen H, Kreiling R, Kreysa J, Leite SB, Loizou G, Maxwell G, Mazzatorta P, Munn S, Pfuhler S, Phrakonkham P, Piersma A, Poth A, Prieto P, Repetto G, Rogiers V, Schoeters G, Schwarz M, Serafimova R, Tähti H, Testai E, van Delft J, van Loveren H, Vinken M, Worth A, Zaldivar JM. Alternative (non-animal) methods for cosmetics testing: current status and future prospects-2010. Arch Toxicol 2011; 85:367-485. [PMID: 21533817 DOI: 10.1007/s00204-011-0693-2] [Citation(s) in RCA: 358] [Impact Index Per Article: 27.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/21/2011] [Accepted: 03/03/2011] [Indexed: 01/09/2023]
Abstract
The 7th amendment to the EU Cosmetics Directive prohibits to put animal-tested cosmetics on the market in Europe after 2013. In that context, the European Commission invited stakeholder bodies (industry, non-governmental organisations, EU Member States, and the Commission's Scientific Committee on Consumer Safety) to identify scientific experts in five toxicological areas, i.e. toxicokinetics, repeated dose toxicity, carcinogenicity, skin sensitisation, and reproductive toxicity for which the Directive foresees that the 2013 deadline could be further extended in case alternative and validated methods would not be available in time. The selected experts were asked to analyse the status and prospects of alternative methods and to provide a scientifically sound estimate of the time necessary to achieve full replacement of animal testing. In summary, the experts confirmed that it will take at least another 7-9 years for the replacement of the current in vivo animal tests used for the safety assessment of cosmetic ingredients for skin sensitisation. However, the experts were also of the opinion that alternative methods may be able to give hazard information, i.e. to differentiate between sensitisers and non-sensitisers, ahead of 2017. This would, however, not provide the complete picture of what is a safe exposure because the relative potency of a sensitiser would not be known. For toxicokinetics, the timeframe was 5-7 years to develop the models still lacking to predict lung absorption and renal/biliary excretion, and even longer to integrate the methods to fully replace the animal toxicokinetic models. For the systemic toxicological endpoints of repeated dose toxicity, carcinogenicity and reproductive toxicity, the time horizon for full replacement could not be estimated.
Collapse
Affiliation(s)
- Sarah Adler
- Centre for Documentation and Evaluation of Alternatives to Animal Experiments (ZEBET), Federal Institute for Risk Assessment (BfR), Berlin, Germany
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|
52
|
Sofuoglu A, Kiymet N, Kavcar P, Sofuoglu SC. Polycyclic and nitro musks in indoor air: a primary school classroom and a women's sport center. INDOOR AIR 2010; 20:515-22. [PMID: 21070376 DOI: 10.1111/j.1600-0668.2010.00674.x] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/07/2023]
Abstract
UNLABELLED Indoor air gas and particulate-phase samples (PM(2.5) ) were collected from a primary school classroom and a women's sport center because children are one of the sensitive population subgroups and women are frequent users of personal care products in addition to the high level of activity in this specific microenvironment. PM(2.5) was collected with a Harvard impactor, and polyurethane foam was used for the gas phase. Samples were ultrasonically extracted, concentrated, and analyzed with a GC-MS. The mean gas-phase concentrations in the classroom ranged from 0.12 ± 0.2 ng/m(3) for MK to 267 ± 56 ng/m(3) for HHCB, while it was from 0.08 ± 0.10 ng/m(3) for AHMI to 144 ± 61 ng/m(3) for HHCB in the sports center. Particulate-phase average concentrations in the sports center ranged from 0.22 ± 0.11 ng/m(3) for ATII to 1.34 ± 071 ng/m(3) for AHTN, while it ranged from 0.05 ± 0.02 ng/m(3) (musk xylene) to 2.50 ± 0.94 ng/m(3) (HHCB) in the classroom. Exposure-risk assessment showed that inhalation route is most probably far less significant than the dermal route; however, it should be noted that the exposure duration covered in this study was not the larger fraction of the day. PRACTICAL IMPLICATIONS Synthetic musk compounds (SMCs) are found everywhere because their use in household and personal care products (laundry detergents, carpet cleaners, cleaning agents, fabric softener soaps, shampoos, cosmetics, etc.) has been increasing. These compounds are semi-volatiles that may result in direct and indirect exposures through inhalation route. Although SMCs were found to be dominant in the gas phase, exposure via inhalable particles may be important as we found several compounds in the particulate phase (PM(2.5)).
Collapse
Affiliation(s)
- A Sofuoglu
- Department of Chemical Engineering, Izmir Institute of Technology, Gülbahçe, Izmir, Turkey.
| | | | | | | |
Collapse
|
53
|
Friedmann PS, Pickard C. Quantifying human susceptibility to contact sensitization; risk assessments now and in the future. Contact Dermatitis 2010; 63:237-47. [DOI: 10.1111/j.1600-0536.2010.01801.x] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
|
54
|
|
55
|
Api AM, Belsito D, Bickers D, Bruze M, Calow P, Greim H, Hanifin JM, McNamee PM, Rogers AE, Saurat JH, Sipes GI, Tagami H. Quantitative Risk Assessment of Contact Sensitization: Clinical Data to Assess Utility of the Model. Dermatitis 2010. [DOI: 10.2310/6620.2010.10032] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
|
56
|
Heratizadeh A, Killig C, Worm M, Soost S, Simon D, Bauer A, Mahler V, Schuster C, Szliska C, Frambach Y, Eben R, Werfel T, Uter W, Schnuch A. Quantitative repeated open application testing with a rinse-off product in methyldibromo glutaronitrile-sensitive patients: results of the IVDK. Contact Dermatitis 2010; 62:330-7. [DOI: 10.1111/j.1600-0536.2010.01726.x] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
|
57
|
Kern PS, Gerberick FG, Ryan CA, Kimber I, Aptula A, Basketter DA. Local Lymph Node Data for the Evaluation of Skin Sensitization Alternatives: A Second Compilation. Dermatitis 2010. [DOI: 10.2310/6620.2009.09038] [Citation(s) in RCA: 147] [Impact Index Per Article: 10.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
|
58
|
Basketter DA. Methyldibromoglutaronitrile: skin sensitization and quantitative risk assessment. Cutan Ocul Toxicol 2009; 29:4-9. [DOI: 10.3109/15569520903351151] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
|
59
|
Loveless SE, Api AM, Crevel RWR, Debruyne E, Gamer A, Jowsey IR, Kern P, Kimber I, Lea L, Lloyd P, Mehmood Z, Steiling W, Veenstra G, Woolhiser M, Hennes C. Potency values from the local lymph node assay: application to classification, labelling and risk assessment. Regul Toxicol Pharmacol 2009; 56:54-66. [PMID: 19733604 DOI: 10.1016/j.yrtph.2009.08.016] [Citation(s) in RCA: 51] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/03/2009] [Revised: 08/31/2009] [Accepted: 08/31/2009] [Indexed: 11/17/2022]
Abstract
Hundreds of chemicals are contact allergens but there remains a need to identify and characterise accurately skin sensitising hazards. The purpose of this review was fourfold. First, when using the local lymph node assay (LLNA), consider whether an exposure concentration (EC3 value) lower than 100% can be defined and used as a threshold criterion for classification and labelling. Second, is there any reason to revise the recommendation of a previous ECETOC Task Force regarding specific EC3 values used for sub-categorisation of substances based upon potency? Third, what recommendations can be made regarding classification and labelling of preparations under GHS? Finally, consider how to integrate LLNA data into risk assessment and provide a rationale for using concentration responses and corresponding no-effect concentrations. Although skin sensitising chemicals having high EC3 values may represent only relatively low risks to humans, it is not possible currently to define an EC3 value below 100% that would serve as an appropriate threshold for classification and labelling. The conclusion drawn from reviewing the use of distinct categories for characterising contact allergens was that the most appropriate, science-based classification of contact allergens according to potency is one in which four sub-categories are identified: 'extreme', 'strong', 'moderate' and 'weak'. Since draining lymph node cell proliferation is related causally and quantitatively to potency, LLNA EC3 values are recommended for determination of a no expected sensitisation induction level that represents the first step in quantitative risk assessment.
Collapse
Affiliation(s)
- S E Loveless
- DuPont Haskell Global Centers for Health and Environmental Sciences, Newark, DE, USA.
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|
60
|
Feasibility study to support a threshold of sensitization concern concept in risk assessment based on human data. Arch Toxicol 2009; 83:1049-60. [DOI: 10.1007/s00204-009-0460-9] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/08/2009] [Accepted: 07/27/2009] [Indexed: 10/20/2022]
|
61
|
|
62
|
Safety evaluation of superabsorbent baby diapers. Regul Toxicol Pharmacol 2009; 53:81-9. [DOI: 10.1016/j.yrtph.2008.10.005] [Citation(s) in RCA: 150] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/09/2008] [Accepted: 10/16/2008] [Indexed: 11/20/2022]
|
63
|
Kwon S, Holland D, Kern P. Skin safety evaluation of laundry detergent products. JOURNAL OF TOXICOLOGY AND ENVIRONMENTAL HEALTH. PART A 2009; 72:1369-1379. [PMID: 20077208 DOI: 10.1080/15287390903212675] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/28/2023]
Abstract
The conduct of a scientifically sound safety assessment of new ingredients and finished products is essential prior to their introduction into the marketplace. Such assessments are based on a risk assessment paradigm established by the National Academy of Science (NAS, 1983) that consists of a four-step process: hazard identification, dose-response assessment, exposure assessment, and risk characterization. This risk assessment paradigm has been (1) used as a framework for estimating an adverse health risk posed by environmental chemicals, and (2) applied to systemic toxicological endpoints. The general principles of risk assessment may be applied to skin safety evaluation of consumer products, considering that dermal toxicity is also a threshold phenomenon. This study describes a risk assessment-based approach for skin safety evaluation of laundry detergent products.
Collapse
Affiliation(s)
- Seok Kwon
- Kobe Technical Center, Procter & Gamble Innovation Godo Kaisha, Kobe, Japan.
| | | | | |
Collapse
|
64
|
Lapczynski A, Bhatia S, Letizia C, Api A. Fragrance material review on rhodinol. Food Chem Toxicol 2008; 46 Suppl 11:S259-62. [DOI: 10.1016/j.fct.2008.06.072] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
|
65
|
Lapczynski A, Bhatia S, Letizia C, Api A. Fragrance material review on l-citronellol. Food Chem Toxicol 2008; 46 Suppl 11:S110-3. [DOI: 10.1016/j.fct.2008.06.056] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
|
66
|
Ryan CA, Chaney JG, Gerberick GF, Kern PS, Dearman RJ, Kimber I, Basketter DA. Extrapolating Local Lymph Node Assay EC3 Values To Estimate Relative Sensitizing Potency. Cutan Ocul Toxicol 2008; 26:135-45. [PMID: 17612980 DOI: 10.1080/15569520701212258] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
Abstract
The assessment of the potency of a skin sensitizing chemical is a key starting point for its subsequent risk assessment/management. The Local Lymph Node Assay can provide information on the relative skin sensitizing potency of contact allergens by interpolation from the dose response curve the concentration of a chemical required to elicit a threshold positive response (EC3 value). However, interpolation requires that the dose response curve have at least one stimulation index (SI) value above and one SI value below the threshold value of 3. For instances where all test concentrations result in SI values above 3, there was a need to develop a method that would permit estimation of EC3 values. This has been achieved by log-linear extrapolation using the two lowest test concentrations from the dose response curve. Before applying this approach, it is important that data quality is assessed. The dose response must include concentrations on the linear portion of the curve and, ideally, the SI induced by the lowest dose should approach 3. Judicious use of this approach for extrapolating EC3 values can provide information on a likely potency classification for use in risk assessment and may avoid the need for repeat animal testing.
Collapse
Affiliation(s)
- Cindy A Ryan
- The Procter & Gamble Company. Cincinnati, Ohio, USA.
| | | | | | | | | | | | | |
Collapse
|
67
|
McNamee PM, Api AM, Basketter DA, Frank Gerberick G, Gilpin DA, Hall BM, Jowsey I, Robinson MK. A review of critical factors in the conduct and interpretation of the human repeat insult patch test. Regul Toxicol Pharmacol 2008; 52:24-34. [DOI: 10.1016/j.yrtph.2007.10.019] [Citation(s) in RCA: 50] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2007] [Revised: 10/18/2007] [Accepted: 10/22/2007] [Indexed: 11/30/2022]
|
68
|
Lalko J, Api AM. Citral: Identifying a threshold for induction of dermal sensitization. Regul Toxicol Pharmacol 2008; 52:62-73. [DOI: 10.1016/j.yrtph.2008.01.006] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/17/2007] [Revised: 12/22/2007] [Accepted: 01/09/2008] [Indexed: 10/22/2022]
|
69
|
Axilla surface area for males and females: Measured distribution. Regul Toxicol Pharmacol 2008; 52:46-52. [DOI: 10.1016/j.yrtph.2007.12.006] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/08/2007] [Revised: 11/30/2007] [Accepted: 12/07/2007] [Indexed: 11/19/2022]
|
70
|
Dose metrics in the acquisition of skin sensitization: Thresholds and importance of dose per unit area. Regul Toxicol Pharmacol 2008; 52:39-45. [DOI: 10.1016/j.yrtph.2008.01.010] [Citation(s) in RCA: 60] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/17/2007] [Revised: 01/10/2008] [Accepted: 01/14/2008] [Indexed: 11/21/2022]
|
71
|
Jowsey IR, Clapp CJ, Safford B, Gibbons BT, Basketter DA. The impact of vehicle on the relative potency of skin-sensitizing chemicals in the local lymph node assay. Cutan Ocul Toxicol 2008; 27:67-75. [PMID: 18568891 DOI: 10.1080/15569520801904655] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
Abstract
The identification and characterization of chemicals that possess skin-sensitizing potential are typically performed using predictive tests. However, human exposure to skin-sensitizing chemicals often occurs via a matrix (vehicle) that differs from that used in these tests. It is thus important to account for the potential impact of vehicle differences when undertaking quantitative risk assessment for skin sensitization. This is achieved through the application of a specific sensitization assessment factor (SAF), scaled between 1 and 10, when identifying an acceptable exposure level. The objective of the analysis described herein is to determine the impact of vehicle differences on local lymph node assay (LLNA) EC3 values (concentrations of test chemical required to provoke a 3-fold increase in lymph node cell proliferation). Initially, the inherent variability of the LLNA was investigated by examining the reproducibility of EC3 values for 14 chemicals that have been tested more than once in the same vehicle (4:1 acetone:olive oil, AOO). This analysis reveals that the variability in EC3 value for these chemicals following multiple assessments is <5-fold. Next, data from the literature and previously unpublished studies were compiled for 18 chemicals that had been assessed in the LLNA using at least 2 of 15 different vehicles. These data demonstrate that often the variability in EC3 values observed for a given chemical in different vehicles is no greater than the 5-fold inherent variability observed when assessing a chemical in the same vehicle on multiple occasions. However, there are examples where EC3 values for a chemical differ by a factor of more than 10 between different vehicles. These observations were often associated with an apparent underestimation of potency (higher EC3 values) with predominantly aqueous vehicles or propylene glycol. These data underscore the need to consider vehicle effects in the context of skin-sensitization risk assessments.
Collapse
Affiliation(s)
- Ian R Jowsey
- Unilever Safety and Environmental Assurance Centre, Colworth Park, Sharnbrook, Bedfordshire, UK.
| | | | | | | | | |
Collapse
|
72
|
Abstract
Allergic contact dermatitis (ACD) is to a considerable extent a preventable disease. Limitation can be achieved by correct identification of skin sensitizers, characterization of their potency, understanding human skin exposure and application of good risk assessment/management strategies. Various methods exist which are accurate for the predictive identification of chemicals that possess skin-sensitizing properties. These are enshrined in regulations that aim to provide a harmonized approach to hazard identification. One of the methods, the local lymph node assay, also delivers information on the relative potency of sensitizers. Efforts are continuing in the European Union and at the Organization for Economic Cooperation and Development to use elements of this information for regulatory categorization of skin sensitizers. However, greater use can be made of this potency information in the application of quantitative risk assessments. Such assessments depend also on the availability of accurate data on human skin exposure, one aspect where legislation has little role to play. Management of risks by restriction of skin exposure is, in contrast, a key point where legislation can play an important role, helping to establish a level playing field for industry and setting good standards based on the legislator's ability to access all data. Ultimately, the combination of accurate hazard identification, potency measurement, risk assessment and management, underpinned by enabling legislation, will lead to reduction of ACD. For individuals who do still develop contact allergy, avoidance of ACD should continue to be a goal, based on raising awareness of skin protection, allergen labelling and other skincare strategies.
Collapse
Affiliation(s)
- D A Basketter
- St John's Institute of Dermatology, St Thomas' Hospital, London, UK.
| |
Collapse
|
73
|
Basketter DA, Clapp CJ, Safford BJ, Jowsey IR, McNamee P, Ryan CA, Gerberick FG. Preservatives and Skin Sensitization Quantitative Risk Assessment. Dermatitis 2008. [DOI: 10.2310/6620.2008.07018] [Citation(s) in RCA: 42] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
|
74
|
|
75
|
Lalko J, Lapczynski A, McGinty D, Bhatia S, Letizia CS, Api AM. Fragrance material review on gamma-damascone. Food Chem Toxicol 2007; 45 Suppl 1:S216-20. [PMID: 18031909 DOI: 10.1016/j.fct.2007.09.064] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
A toxicologic and dermatologic review of gamma-damascone when used as a fragrance ingredient is presented.
Collapse
Affiliation(s)
- J Lalko
- Research Institute for Fragrance Materials, Inc., 50 Tice Boulevard, Woodcliff Lake, NJ 07677, USA
| | | | | | | | | | | |
Collapse
|
76
|
Lalko J, Lapczynski A, McGinty D, Bhatia S, Letizia CS, Api AM. Fragrance material review on delta-damascone. Food Chem Toxicol 2007; 45 Suppl 1:S205-10. [PMID: 18031903 DOI: 10.1016/j.fct.2007.09.058] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
A toxicologic and dermatologic review of delta-damascone when used as a fragrance ingredient is presented.
Collapse
Affiliation(s)
- J Lalko
- Research Institute for Fragrance Materials, Inc. 50 Tice Boulevard, Woodcliff Lake, NJ 07677, USA
| | | | | | | | | | | |
Collapse
|
77
|
Lapczynski A, Lalko J, McGinty D, Bhatia S, Letizia CS, Api AM. Fragrance material review on methyl-alpha-ionone. Food Chem Toxicol 2007; 45 Suppl 1:S276-9. [PMID: 18022306 DOI: 10.1016/j.fct.2007.09.020] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
A toxicologic and dermatologic review of methyl-alpha-ionone when used as a fragrance ingredient is presented.
Collapse
Affiliation(s)
- A Lapczynski
- Research Institute for Fragrance Materials, Inc., 50 Tice Boulevard, Woodcliff Lake, NJ 07677, USA.
| | | | | | | | | | | |
Collapse
|
78
|
Wang TF, Kasting GB, Nitsche JM. A multiphase microscopic diffusion model for stratum corneum permeability. II. estimation of physicochemical parameters, and application to a large permeability database. J Pharm Sci 2007; 96:3024-51. [PMID: 17876780 DOI: 10.1002/jps.20883] [Citation(s) in RCA: 93] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
The full parameterization for the stratum corneum biphasic microtransport model presented previously in this Journal [95:620-648 (2006)] is developed through a combination of fundamental transport theory and calibration with existing data. Of the five microscopic transport properties, four (D(cor), K(cor/w), D(lip), K(lip/w)) are developed from sources independent of the existing steady-state permeability database. The fifth parameter, k(trans) (the mass transfer coefficient for transbilayer hopping), is derived from a fit of the model to the permeability data according to a modified free surface area function of the form log(10) k(trans) = A-B x (MW)(1/3). Examination of the experimental data in terms of the two dimensionless groups, R and sigma, arising from the analysis leads to the conclusion that SC permeation for most compounds is dominated by the transcellular pathway regardless of their lipophilicity, a striking departure from recent skin permeability models. Overall fit of the developed model(s) to the permeability data is somewhat better than for the Potts-Guy equation and variants thereof; however, marked improvement is seen in the estimation of lag times and the related potential for predicting skin hydration effects and transient skin permeation profiles. Simple approximations to the full numerical solution are presented that allow the developed model(s) to be implemented on a spreadsheet.
Collapse
Affiliation(s)
- Tsuo-Feng Wang
- Department of Chemical and Biological Engineering, University at Buffalo, State University of New York, Buffalo, New York 14260-4200, USA
| | | | | |
Collapse
|
79
|
Dermal sensitization quantitative risk assessment (QRA) for fragrance ingredients. Regul Toxicol Pharmacol 2007; 52:3-23. [PMID: 18406028 DOI: 10.1016/j.yrtph.2007.10.008] [Citation(s) in RCA: 204] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/16/2007] [Accepted: 10/04/2007] [Indexed: 11/20/2022]
Abstract
Based on chemical, cellular, and molecular understanding of dermal sensitization, an exposure-based quantitative risk assessment (QRA) can be conducted to determine safe use levels of fragrance ingredients in different consumer product types. The key steps are: (1) determination of benchmarks (no expected sensitization induction level (NESIL)); (2) application of sensitization assessment factors (SAF); and (3) consumer exposure (CEL) calculation through product use. Using these parameters, an acceptable exposure level (AEL) can be calculated and compared with the CEL. The ratio of AEL to CEL must be favorable to support safe use of the potential skin sensitizer. This ratio must be calculated for the fragrance ingredient in each product type. Based on the Research Institute for Fragrance Materials, Inc. (RIFM) Expert Panel's recommendation, RIFM and the International Fragrance Association (IFRA) have adopted the dermal sensitization QRA approach described in this review for fragrance ingredients identified as potential dermal sensitizers. This now forms the fragrance industry's core strategy for primary prevention of dermal sensitization to these materials in consumer products. This methodology is used to determine global fragrance industry product management practices (IFRA Standards) for fragrance ingredients that are potential dermal sensitizers. This paper describes the principles of the recommended approach, provides detailed review of all the information used in the dermal sensitization QRA approach for fragrance ingredients and presents key conclusions for its use now and refinement in the future.
Collapse
|
80
|
Api AM, Bredbenner A, McGowen M, Niemiera D, Parker L, Renskers K, Selim S, Sgaramella R, Signorelli R, Tedrow S, Troy W. Skin contact transfer of three fragrance residues from candles to human hands. Regul Toxicol Pharmacol 2007; 48:279-83. [PMID: 17560701 DOI: 10.1016/j.yrtph.2007.03.008] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/06/2006] [Indexed: 11/29/2022]
Abstract
The dermal hand transfer of three fragrance materials (cinnamic aldehyde, d-limonene and eugenol) from scented candles was determined in 10 subjects (i.e., 20 hands) after grasping scented candles for 5 consecutive 20s exposures/grasps. The fragrance materials from each subject's hands were recovered by isopropyl alcohol wipes and subsequent extractions. Removal efficiencies for both cinnamic aldehyde and eugenol placed directly on the hands were not concentration dependent and ranged from 103% to 106%. The removal efficiency of d-limonene showed an inverse relation with 74.3% removed at the low concentration of 50 microg and 63.8% removed at the high concentration of 500 microg. The residue/transfer of d-limonene from the candles to the hands was below the limit of detection of 50 microg. The residue/transfer of cinnamic aldehyde and eugenol to each subject's hands was consistent between subjects as well as between each exposure/grasp. The total mean residues of cinnamic aldehyde and eugenol transferred per grasp from the candles to the hands were 0.255 microg/cm(2) and 0.279 microg/cm(2), respectively.
Collapse
Affiliation(s)
- Anne Marie Api
- Research Institute for Fragrance Materials Inc., 50 Tice Boulevard, Woodcliff Lake, NJ 07677, USA.
| | | | | | | | | | | | | | | | | | | | | |
Collapse
|
81
|
Basketter DA, Gerberick F, Kimber I. The local lymph node assay and the assessment of relative potency: status of validation. Contact Dermatitis 2007; 57:70-5. [PMID: 17627643 DOI: 10.1111/j.1600-0536.2007.01141.x] [Citation(s) in RCA: 89] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
For the prediction of skin sensitization potential, the local lymph node assay (LLNA) is a fully validated alternative to guinea-pig tests. More recently, information from LLNA dose-response analyses has been used to assess the relative potency of skin sensitizing chemicals. These data are then deployed for risk assessment and risk management. In this commentary, the utility and validity of these relative potency measurements are reviewed. It is concluded that the LLNA does provide a valuable assessment of relative sensitizing potency in the form of the estimated concentration of a chemical required to produce a threefold stimulation of draining lymph node cell proliferation compared with concurrent controls (EC3 value) and that all reasonable validation requirements have been addressed successfully. EC3 measurements are reproducible in both intra- and interlaboratory evaluations and are stable over time. It has been shown also, by several independent groups, that EC3 values correlate closely with data on relative human skin sensitization potency. Consequently, the recommendation made here is that LLNA EC3 measurements should now be regarded as a validated method for the determination of the relative potency of skin sensitizing chemicals, a conclusion that has already been reached by a number of independent expert groups.
Collapse
Affiliation(s)
- David A Basketter
- Unilever Safety and Environmental Assurance Centre, Colworth Park, Sharnbrook, Bedfordshire, UK.
| | | | | |
Collapse
|
82
|
Schnuch A, Uter W, Geier J, Lessmann H, Frosch PJ. Sensitization to 26 fragrances to be labelled according to current European regulation. Contact Dermatitis 2007; 57:1-10. [PMID: 17577350 DOI: 10.1111/j.1600-0536.2007.01088.x] [Citation(s) in RCA: 165] [Impact Index Per Article: 9.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Abstract
To study the frequency of sensitization to 26 fragrances to be labelled according to current European regulation. During 4 periods of 6 months, from 1 January 2003 to 31 December 2004, 26 fragrances were patch tested additionally to the standard series in a total of 21 325 patients; the number of patients tested with each of the fragrances ranged from 1658 to 4238. Hydroxymethylpentylcyclohexene carboxaldehyde (HMPCC) was tested throughout all periods. The following frequencies of sensitization (rates in %, standardized for sex and age) were observed: tree moss (2.4%), HMPCC (2.3), oak moss (2.0), hydroxycitronellal (1.3), isoeugenol (1.1), cinnamic aldehyde (1.0), farnesol (0.9), cinnamic alcohol (0.6), citral (0.6), citronellol (0.5), geraniol (0.4), eugenol (0.4), coumarin (0.4), lilial (0.3), amyl-cinnamic alcohol (0.3), benzyl cinnamate (0.3), benzyl alcohol (0.3), linalool (0.2), methylheptin carbonate (0.2), amyl-cinnamic aldehyde (0.1), hexyl-cinnamic aldehyde (0.1), limonene (0.1), benzyl salicylate (0.1), gamma-methylionon (0.1), benzyl benzoate (0.0), anisyl alcohol (0.0). 1) Substances with higher sensitization frequencies were characterized by a considerable number of '++/+++' reactions. 2) Substances with low sensitization frequencies were characterized by a high number of doubtful/irritant and a low number of stronger (++/+++) reactions. 3) There are obviously fragrances among the 26 which are, with regard to contact allergy, of great, others of minor, and some of no importance at all.
Collapse
Affiliation(s)
- Axel Schnuch
- Zentrale des IVDK, Institut an der Universität Göttingen, Germany.
| | | | | | | | | |
Collapse
|
83
|
Jowsey IR. Proactive surveillance of contact allergies: an important component of the risk management strategy for skin sensitizers. Contact Dermatitis 2007; 56:305-10. [PMID: 17577370 DOI: 10.1111/j.1600-0536.2006.01082.x] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
Risk assessment serves to ensure that dermal exposure to skin sensitizers does not result in the acquisition of allergic skin disease. Traditionally, the approach adopted was one of comparative analysis, involving benchmarking against other allergens of known potency. More recently, efforts have been made to embrace a quantitative risk assessment (QRA) approach. However, the accuracy of any risk assessment is reflected in the extent to which it meets the fundamental objective stated above. Thus, clinical experience is of key importance. There exists the possibility for the originators of risk assessments relating to chemicals that possess skin-sensitizing potential to work directly with the clinical community to proactively obtain this experience through specific surveillance programmes. This forms the focus of this review article. The current status of the QRA approach is considered initially. A recently published example of one such surveillance programme that was undertaken as a collaborative initiative between industry and the clinical community is then reviewed. Finally, a possible strategy for the future is presented, in which it is suggested that surveillance strategies might be deployed in certain situations as an adjunct to the initial risk assessment. It is hoped that such a framework might further improve the efficacy of future approaches to skin sensitization risk assessment.
Collapse
Affiliation(s)
- Ian R Jowsey
- Unilever Safety and Environmental Assurance Centre, Colworth Park, Sharnbrook, Bedfordshire MK44 1LQ, UK.
| |
Collapse
|
84
|
Jowsey IR, Kligman AM, White IR, Goossens A, Basketter DA. Evidence that two alkyl ester quaternary ammonium compounds lack substantial human skin-sensitizing potential. Dermatitis 2007; 18:32-9. [PMID: 17303042 DOI: 10.2310/6620.2007.06036] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
BACKGROUND Alkyl ester quaternary ammonium compounds (ester quats) are used extensively in fabric rinse conditioners. It is important to document in the literature the outcome of historical studies that were performed to assess the risk of adverse skin effects associated with their use. OBJECTIVES (1) To document the outcomes of historical studies performed to evaluate the skin sensitizing potential of two ester quats (the di-[hardened tallow fatty acid] ester of 2,3-dihydroxypropyl-trimethyl ammonium chloride [HEQ] and the dialkyl ester of triethanol ammonium methyl sulfate [TEA-Quat]) and (2) to demonstrate that these ester quats lack marked skin-sensitizing potential in humans, such that they do not present a risk of contact allergy for consumers who use fabric rinse conditioners. METHODS Each material was assessed in the human maximization test in a panel of 25 volunteers. Diagnostic patch testing was also performed with each material in a population of 239 patients undergoing routine patch testing for suspected allergic contact dermatitis. These data are also considered in the context of an exposure-based quantitative risk assessment. RESULTS Neither HEQ nor TEA-Quat was found to cause skin sensitization under the conditions of the human maximization test. No evidence of contact allergy to the materials was found among the relatively small population assessed by diagnostic patch testing. CONCLUSIONS This study provides evidence that HEQ and TEA-Quat lack substantial skin-sensitizing potential in humans. Taken together with similar data for other ester quats, it suggests that compounds in this class are unlikely to be significant human contact allergens.
Collapse
Affiliation(s)
- Ian R Jowsey
- Unilever Safety and Environmental Assurance Centre, Colworth Park, Sharnbrook, Bedforshire, UK.
| | | | | | | | | |
Collapse
|
85
|
Basketter DA, Sanders D, Jowsey IR. The skin sensitization potential of resorcinol: experience with the local lymph node assay. Contact Dermatitis 2007; 56:196-200. [PMID: 17343618 DOI: 10.1111/j.1600-0536.2006.01008.x] [Citation(s) in RCA: 37] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Resorcinol is a simple aromatic chemical (1,3-benzenediol) that has found widespread use, particularly as a coupler in hair dyes. Clinical experience clearly shows that resorcinol is a (albeit uncommon) skin sensitizer. By contrast, predictive methods, both animal and human, have previously failed to identify resorcinol as such. Here, we describe the outcome of a recent local lymph node assay performed in accordance with Organisation for Economic Co-operation and Development guideline 429, which correctly identified resorcinol as a skin sensitizer. Clear evidence of a dose response was apparent, and an EC3 value of approximately 6% was calculated. This suggests that the skin-sensitizing potency of resorcinol is approximately 2 orders of magnitude lower than that of p-phenylenediamine but similar to that of hexyl cinnamic aldehyde. These data show the importance of adherence to test guidelines and aligns the clinical experience with resorcinol with that obtained in predictive animal methods.
Collapse
Affiliation(s)
- David A Basketter
- Safety and Environmental Assurance Centre, Unilever, Colworth Park, Sharnbrook, Bedfordshire MK44 1LQ, UK.
| | | | | |
Collapse
|
86
|
|
87
|
|
88
|
Lapczynski A, Lalko J, McGinty D, Bhatia S, Letizia C, Api A. Fragrance material review on cis-α-damascone. Food Chem Toxicol 2007; 45 Suppl 1:S188-91. [DOI: 10.1016/j.fct.2007.09.054] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022]
|
89
|
Lalko J, Lapczynski A, McGinty D, Bhatia S, Letizia C, Api A. Fragrance material review on isodamascone. Food Chem Toxicol 2007; 45 Suppl 1:S258-62. [DOI: 10.1016/j.fct.2007.09.069] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
|
90
|
|
91
|
|
92
|
Basketter DA, Jefferies D, Safford BJ, Gilmour NJ, Jowsey IR, McFadden J, Chansinghakul W, Duangdeeden I, Kullavanijaya P. The impact of exposure variables on the induction of skin sensitization. Contact Dermatitis 2006; 55:178-85. [PMID: 16918618 DOI: 10.1111/j.1600-0536.2006.00906.x] [Citation(s) in RCA: 51] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Whereas many investigations of the variables associated with the elicitation of allergic contact dermatitis have been undertaken, to the point where we can begin to predict the likelihood of elicitation occurring in a given situation, the same is not true for the induction of skin sensitization. Studies have demonstrated that increasing dose has an impact; in an experimental setting, a number of variables received attention some decades ago. However, in the work reported here, the relative importance of the frequency and the duration of exposure is highlighted. In an investigation using a human repeated insult patch test, it was demonstrated that reduction of the exposure duration from 48 hr to 5 min decreased the rate of sensitization to 1% p-phenylenediamine (PPD) from 54% to 3%. However, in an extended clinical study, it was observed that infrequent but longer duration and higher concentration exposure to PPD was significantly less likely to induce sensitization compared to more frequent, short duration, and lower concentration exposure. Detailed statistical analysis of the results indicated that the most important factor driving the induction of skin sensitization was the number of exposures.
Collapse
Affiliation(s)
- David A Basketter
- Safety and Environmental Assurance Centre, Unilever Colworth, Sharnbrook, Bedfordshire MK44 1PR, UK.
| | | | | | | | | | | | | | | | | |
Collapse
|
93
|
Zachariae C, Lerbaek A, McNamee PM, Gray JE, Wooder M, Menné T. An evaluation of dose/unit area and time as key factors influencing the elicitation capacity of methylchloroisothiazolinone/methylisothiazolinone (MCI/MI) in MCI/MI-allergic patients. Contact Dermatitis 2006; 55:160-6. [PMID: 16918615 DOI: 10.1111/j.1600-0536.2006.00895.x] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Methylchloroisothiazolinone and methylisothiazolinone (MCI/MI) contact allergy affects 1-3% of patch-tested patients in European centres. The aim of the present study was to evaluate the importance of the factors--time and concentration (dose/per unit area)--in the elicitation capacity by means of a repeated open application test (ROAT) experimental design. The study was designed as a double-blind, placebo-controlled, dose-response ROAT preceded by a diagnostic patch testing. 25 subjects with confirmed MCI/MI allergy and 10 healthy, non-MCI/MI allergic control subjects were exposed to 0.025 microg/cm2 (2 p.p.m.) of MCI/MI/unit area of the skin for 4 weeks. After a wash-out period of at least 4 weeks, the subjects were exposed to 0.094 microg/cm2 (7.5 p.p.m.) of MCI/MI/unit area of the skin for 4 weeks. The study showed the importance of both time and exposure in the elicitation process. It demonstrated that the elicitation threshold for MCI/MI is expected to be in the proximity of 0.025 microg/cm2 although it was not possible to establish a definitive elicitation threshold for MCI/MI in this study.
Collapse
Affiliation(s)
- Claus Zachariae
- Department of Dermatology, Gentofte Hospital, University of Copenhagen, 2900 Hellerup, Denmark.
| | | | | | | | | | | |
Collapse
|
94
|
Bramante M. Genital Hygiene. THE VULVA 2006:183-216. [DOI: 10.1201/9781420005318-13] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 09/02/2023]
|
95
|
Corea NV, Basketter DA, Clapp C, Van Asten A, Marty JP, Pons-Guiraud A, Laverdet C. Fragrance allergy: assessing the risk from washed fabrics. Contact Dermatitis 2006; 55:48-53. [PMID: 16842555 DOI: 10.1111/j.0105-1873.2006.00872.x] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/01/2022]
Abstract
The prevalence of contact allergy to fragrance ingredients increased during the last part of the 20th century with the consequence that a substantial number of individuals are at risk of experiencing allergic contact dermatitis (ACD) if they have a sufficient degree of skin exposure to the chemical to which they have become sensitized. Such exposure does not necessarily have to arise from the type of source that originally induced the sensitization. A number of sources of exposure are clearly associated with risk of elicitation of ACD, but the role of fragrance deposited on fabrics, for example as a result of laundry processes, also can be questioned. In this article, firstly, the risk of the induction of fragrance-related ACD from exposure to fragrance via fabric is considered. Using a quantitative risk-assessment approach, the risk appears to be extremely low. The possibility that fragrance residues on laundered fabrics might elicit reactions in those already sensitized by a different route is also discussed. Clinically, clothing pattern dermatitis associated with fragrance allergy is almost never observed, although this could be investigated clinically by exposing sensitized individuals to the relevant fragrance allergen.
Collapse
Affiliation(s)
- Namali V Corea
- Safety and Environmental Assurance Centre, Unilever Colworth, Sharnbrook, Bedfordshire MK44 1LQ, UK.
| | | | | | | | | | | | | |
Collapse
|
96
|
Wang TF, Kasting GB, Nitsche JM. A multiphase microscopic diffusion model for stratum corneum permeability. I. Formulation, solution, and illustrative results for representative compounds. J Pharm Sci 2006; 95:620-48. [PMID: 16447176 DOI: 10.1002/jps.20509] [Citation(s) in RCA: 113] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
A two-dimensional microscopic transport model of the stratum corneum (SC) incorporating corneocytes of varying hydration and permeability embedded in an anisotropic lipid matrix is presented. Results are expressed in terms of a dimensionless permeability (P(SC/w)(comp), which is a function of two dimensionless parameters, R and sigma. R is a ratio of transbilayer to lateral molecular flows within a lipid bilayer and sigma is the ratio of (lateral) permeability in the lipid phase, D(lip)K(lip/w), to that in the corneocyte phase, D(cor)K(cor/w.) The shape of the dimensionless permeability surface is also governed by the arrangement of the SC lipids, where Model 1 represents the extreme in which lipid-phase transport can occur with no transbilayer transport, whereas Model 2 entails maximum transbilayer transport. Model calculations are exemplified by characterizing the skin permeability of four representative permeants: water, ethanol, nicotinamide, and testosterone. A comparison with experimental steady state permeability and partition data supports that the transport properties of the SC lipids are highly anisotropic, with lateral diffusivities several orders of magnitude higher than the equivalent diffusivity calculated from transbilayer hopping. Nevertheless, the calculations suggest that corneocyte-phase transport plays a major role for all four permeants. These results confirm our previous calculations on water permeability and present a marked contrast to the commonly stated doctrine that the SC transport pathway is primarily intercellular.
Collapse
Affiliation(s)
- Tsuo-Feng Wang
- Department of Chemical and Biological Engineering, University at Buffalo, State University of New York, Buffalo, 14260-4200, USA
| | | | | |
Collapse
|
97
|
Lalko J, Api AM. Investigation of the dermal sensitization potential of various essential oils in the local lymph node assay. Food Chem Toxicol 2006; 44:739-46. [PMID: 16324777 DOI: 10.1016/j.fct.2005.10.006] [Citation(s) in RCA: 60] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/06/2005] [Revised: 09/30/2005] [Accepted: 10/13/2005] [Indexed: 11/16/2022]
Abstract
Essential oils are commonly used fragrance ingredients. The oils themselves are complex mixtures, which may contain naturally occurring contact sensitizers. The local lymph node assay was used to evaluate the dermal sensitization potential of basil, citronella, clove leaf, geranium, litsea cubeba, lemongrass, and palmarosa oils. Three of the major components--citral, eugenol, and geraniol--were included to investigate any difference in sensitization potential arising from their exposure in a mixture. Each fragrance material was tested at five concentration ranging from 2.5% to 50% w/v in 1:3 ethanol:diethyl phthalate. The stimulation index (SI) values were calculated for each dose level, an SI > or = 3 was considered a positive response. The estimated concentration (EC3) required to elicit a positive was calculated and taken as a measure of relative potency. The EC3 values and potency classification for basil, clove leaf, litsea cubeba, lemongrass and palmarosa oils were calculated to be <2.5% (> or = moderate), 7.1% (weak), 8.4% (weak), 6.5% (weak) and 9.6% (weak), respectively. Citronella and geranium oils were negative. The individual components citral, eugenol and geraniol resulted in EC3 values of 6.3%, 5.4% and 11.4%, respectively. In general, the potency of each essential oil did not differ significantly from that observed for its main individual component.
Collapse
Affiliation(s)
- J Lalko
- Research Institute for Fragrance Materials, Inc., 50 Tice Boulevard, Woodcliff Lake, NJ 07677, USA.
| | | |
Collapse
|
98
|
|
99
|
Mahony C, Felter SP, McMillan DA. An exposure-based risk assessment approach to confirm the safety of hydrogen peroxide for use in home tooth bleaching. Regul Toxicol Pharmacol 2006; 44:75-82. [PMID: 16289279 DOI: 10.1016/j.yrtph.2005.09.003] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/06/2005] [Indexed: 10/25/2022]
Abstract
Hydrogen peroxide has a long history of safe use in a wide variety of medical and consumer products, including oral care products. The use of hydrogen peroxide in tooth bleaching has been extended to home use. Because this represents a new use, questions have been raised regarding safety, particularly the potential for peroxide tooth-whitening products to increase the risk of oral cancer in high-risk individuals (e.g., smokers and drinkers). These concerns are based on limited experimental data in animals that hydrogen peroxide has extremely weak tumor promoting activity and a lack of publicly available data on exposure to peroxides from the home use of tooth-whitening products. This paper provides a weight-of-evidence cancer hazard characterization for hydrogen peroxide and presents a quantitative risk assessment that confirms a favorable human safety profile risk associated with low levels of exposure to hydrogen peroxide from the use of tooth-whitening products. This includes a lack of tumor promotion risk which is important because tooth-whitening products are often used by chronic smokers and drinkers, who may represent a susceptible subpopulation because of their exposure to other known carcinogens.
Collapse
Affiliation(s)
- C Mahony
- The Procter & Gamble Co., Rusham Park Technical Centre, Egham, Surrey, UK.
| | | | | |
Collapse
|
100
|
Nitsche JM, Wang TF, Kasting GB. A Two-Phase Analysis of Solute Partitioning into the Stratum Corneum. J Pharm Sci 2006; 95:649-66. [PMID: 16432875 DOI: 10.1002/jps.20549] [Citation(s) in RCA: 84] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
An analysis is presented of partition coefficients K(SC/w) describing solute distribution into fully hydrated stratum corneum (SC) from dilute aqueous solution (w). A comprehensive database is compiled from the experimental literature covering more than eight decades in the octanol/water partition coefficient K(o/w). It is analyzed according to a two-phase model following that of Anderson, Raykar, and coworkers (1988, 1989), which accounts for uptake by intercellular lipid and corneocyte (keratin plus water) phases having inherently different lipophilicities, as characterized by an SC lipid/water partition coefficient K(lip/w) and a partition coefficient PC(pro/w) quantifying cornoeocyte-phase binding. Regression of 72 data points yields useful best-fit recalibrations of power laws (or linear free energy relationships) giving K(lip/w) and PC(pro/w) as functions of K(o/w). The specific conclusions of the analysis are as follows: (i) The two-phase model offers substantial improvements over previously proposed analytical representations of K(SC/w), yielding an rms error in log(10)K(SC/w) of 0.30 limited by the scatter in the data. (ii) The best-fit description of the lipid phase is given by the power law K(lip/w) = 0.43 (K(o/w))(0.81), suggesting about half the absolute value of K(lip/w) relative to previous estimates. (iii) The best-fit description of corneocyte-phase binding differs negligibly from the correlation found by Anderson, Raykar, and coworkers for the more limited set of compounds studied by them. Explicit consideration of the two-phase nature of the SC also furnishes a rational basis for predicting the effects of varying hydration state upon K(SC/w).
Collapse
Affiliation(s)
- Johannes M Nitsche
- Department of Chemical and Biological Engineering, University at Buffalo, State University of New York, 14260-4200, USA
| | | | | |
Collapse
|