title: Evaluating the ready biodegradability of two poorly water-soluble substances: comparative approach of bioavailability improvement methods (BIMs).
abstract: Difficulties encountered in estimating the biodegradation of poorly water-soluble substances are often linked to their limited bioavailability to microorganisms. Many original bioavailability improvement methods (BIMs) have been described, but no global approach was proposed for a standardized comparison of these. The latter would be a valuable tool as part of a wider strategy for evaluating poorly water-soluble substances. The purpose of this study was to define an evaluation strategy following the assessment of different BIMs adapted to poorly water-soluble substances with ready biodegradability tests. The study was performed with two poorly water-soluble chemicals-a solid, anthraquinone, and a liquid, isodecyl neopentanoate-and five BIMs were compared to the direct addition method (reference method), i.e., (i) ultrasonic dispersion, (ii) adsorption onto silica gel, (iii) dispersion using an emulsifier, (iv) dispersion with silicone oil, and (v) dispersion with emulsifier and silicone oil. A two-phase evaluation strategy of solid and liquid chemicals was developed involving the selection of the most relevant BIMs for enhancing the biodegradability of tested substances. A description is given of a BIM classification ratio (R BIM), which enables a comparison to be made between the different test chemical sample preparation methods used in the various tests. Thereby, using this comparison, the BIMs giving rise to the greatest biodegradability were ultrasonic dispersion and dispersion with silicone oil or with silicone oil and emulsifier for the tested solid chemical, adsorption onto silica gel, and ultrasonic dispersion for the liquid one.
authors.affiliation: L'Oréal Research & Innovation, Environmental Research Department, 93600, Aulnay-sous-Bois, France. csweetlove@rd.loreal.com.|UMR CNRS 6144 GEPEA CBAC Lab, University of Nantes, 85035, La Roche-sur-Yon, France. csweetlove@rd.loreal.com.
authors.forename: Cyril
authors.initials: C
authors.lastname: Sweetlove
authors.affiliation: L'Oréal Research & Innovation, Environmental Research Department, 93600, Aulnay-sous-Bois, France.
authors.forename: Jean-Charles
authors.initials: JC
authors.lastname: Chenèble
authors.affiliation: Eurofins Expertises Environnementales, Ecotoxicology Lab, 54521, Maxéville, France.
authors.forename: Yves
authors.initials: Y
authors.lastname: Barthel
authors.affiliation: Eurofins Expertises Environnementales, Ecotoxicology Lab, 54521, Maxéville, France.
authors.forename: Marc
authors.initials: M
authors.lastname: Boualam
authors.affiliation: L'Oréal Research & Innovation, Environmental Research Department, 93600, Aulnay-sous-Bois, France.
authors.forename: Jacques
authors.initials: J
authors.lastname: L'Haridon
authors.affiliation: Eurofins Expertises Environnementales, Ecotoxicology Lab, 54521, Maxéville, France.
authors.forename: Gérald
authors.initials: G
authors.lastname: Thouand
mesh_terms: D001673:Biodegradation, Environmental; D001682:Biological Availability; D012995:Solubility; D014867:Water / Q000737:chemistry / Q000378:metabolism*
chemical_list: D014867:Water
keywords: Bioavailability improvement method; Biodegradability; Evaluation strategy; Poorly water-soluble substances; Ready biodegradability test; Silica gel; Silicon oil