The consumer exposure to the vast majority of cosmetic products is limited to dermal contact. Even spray applications tend to be topically exposed to skin or hair. Besides this skin contact, spray products require additional considerations in regard to potential inhalation for building a robust and reliable safety assessment. Over the years, cosmetic industry developed prediction models for the best estimate of inhalation exposure combining data from computer simulation programs available in the market, individual real measured data and last but not least the experience from the market. Such attempt is driven by the toxicological profile of individual used ingredients. The focus of this review is on the determination of inhalation exposure, and the derivation of safe exposure levels for cosmetic spray products. Many of the methods employed to ensure product safety of cosmetic sprays in accordance with the general requirements of the EC Cosmetics Directive are based on industry experience which are not necessarily consistent across companies. This paper presents an approach to compile common principles for risk assessment and thus contribute to standardisation of safety assessment methodologies utilized for spray product evaluation without interfering with the flexibility of the individual safety assessor. It is based on the experience within the author's companies and may be useful as a support document as well for SME (Small and Medium Enterprises) companies safety assessors. In this respect it can be seen as one fundamental step in a tiered approach of cosmetic spray safety evaluation.
Mineral oils and waxes used in cosmetic products, also referred to as "personal care products" outside the European Union, are mixtures of predominantly saturated hydrocarbons consisting of straight-chain, branched and ring structures with carbon chain lengths greater than C16. They are used in skin and lip care cosmetic products due to their excellent skin tolerance as well as their high protecting and cleansing performance and broad viscosity options. Recently, concerns have been raised regarding potential adverse health effects of mineral oils and waxes from dermal application of cosmetics. In order to be able to assess the risk for the consumer the dermal penetration potential of these ingredients has to be evaluated. The scope and objective of this review are to identify and summarize publicly available literature on the dermal penetration of mineral oils and waxes as used in cosmetic products. For this purpose, a comprehensive literature search was conducted. A total of 13 in vivo (human, animal) and in vitro studies investigating the dermal penetration of mineral oils and waxes has been identified and analysed. The majority of the substances were dermally adsorbed to the stratum corneum and only a minor fraction reached deeper skin layers. Overall, there is no evidence from the various studies that mineral oils and waxes are percutaneously absorbed and become systemically available. Thus, given the absence of dermal uptake, mineral oils and waxes as used in cosmetic products do not present a risk to the health of the consumer.
Using perethylated P-cyclodextrin as a chiral stationary phase the alcohols 2-methyl-1-butanol (l), -pentanol (2), -hexanol (3) and 2-ethyl-1-hexanol (4), the free carboxylic acids 2-methyl-butanoic (S), -pentanoic (6), -hexanoic (7) and 2-ethylhexanoic (8) as well as the esters methyl and ethyl 2-methylbutanote (9, 10) are resolved into their mirror images without derivatization. Chiral capillary gas chromatography was used to determine the enantiomeric distribution of the 2-methylbutanoates 9 and 10 in pineapples and 15 apple varieties, using extractive and dynamic headspace methods, respectively.
Racemic 2-alkylbranched acids are transformed to diastereomeric derivatives with (S)-2-hydroxy-3-phenylpropionic acid-N-methylamide or (S)-(-)-l-phenylethylamine and separated by liquid chromatography to pure diastereoisomers, which are subsequently hydrolyzed to yield optically pure acids. Enantiomeric alcohols are generated by LiAlH 4 -reduction of the corresponding acids, esters are synthesized by different methods. The odour impression of the enantiomeric compounds is investigated.2-Alkylalkanoic acids, esters and alcohols are well appreciated aroma compounds of fruits and other foodstuffs 1). In particuliar 2-methylbutanoic acid and its esters are known to be important compounds of fruits like apples 2) and pineapples 3). Until now odour quality only was investigated with racemic substances of this type, although it is generally known that enantiomers may exhibit rather different odour sensations 4 ). 2-Alkylbranched acids and alcohols are important for pheromone synthesis and liquid crystal investigations, too. Recently, investigations on lipase-catalyzed enantioselective esterification of 2-methylalkanoic acids have been reported by EngeI 5 ).This paper now describes the generation of optically pure 2-methylbutanoic acid (1), 2-methylpentanoic acid (2) 2-methylhexanoic acid (3), 2-ethylhexanoic acid (4), the corresponding alcohols 2-methyl-butan-l-01 (5), 2-methyl-pentan-I-ol (6), 2-methyl-hexan-I-ol (7), 2-ethyl-hexan-l-ol (8) and the esters etlJyl-2-methylbutanoate (9) and prenyl-2-methylpentanoate (10).In order to determine their absolute configurations racemic acids 1-4 were converted to diastereomeric amides with (S)-(-)-l-phenylethylamine (SPEA) and chromatographically (LC) separated into optically pure diastereoisomers. Diastereomeric amides were prepared either by a way earlier described by Kaneda 6 ) with equimolar ratio of free acid and free amide by catalysis of N,N'-Dicylclohexylcarbodiimide (DCC) in dry tetrahydrofurane (THF) or by an other way versus acid chloride and free amine under catalysis of 4-Dimethylaminopyridine (DMAP). Absolute configurations of the 2-alkylalkanoic acids moieties were eludicated by comparison with easily available (S)-2-methylbutanoic acid la and by IH-NMR data of tlJeir diastereomeric (S)-1-phenylethylamides 7 ) (Helmchen's model), by chromatographic behaviour of tlJese 965
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