Harmonisation of read-across methodology for drug substance extractables and leachables (E&Ls).

Health-based exposure limits (HBELs) are derived for leachables from polymeric components that interact with the drug substance which exceed a safety concern threshold (SCT). However, given the nature of leachables, there is not always chemical-specific toxicology data. Read-across methodology specific to extractables and leachables (E&Ls) was developed based on survey data collected from 11 pharmaceutical companies and methodology used in other industries.

Development of Duration-Based Non-Mutagenic Thresholds of Toxicological Concern (TTCs) Relevant to Parenteral Extractables and Leachables (E&Ls).

The threshold of toxicological concern (TTC), i.e., the dose of a compound lacking sufficient experimental toxicity data that is unlikely to result in an adverse health effect in humans, is important for evaluating extractables and leachables (E&Ls) as it guides analytical testing and minimizes the use of animal studies.

Considerations when deriving compound-specific limits for extractables and leachables from pharmaceutical products: Four case studies.

Leachables from pharmaceutical container closure systems are a subset of impurities that present in drug products and may pose a risk to patients or compromise product quality. Extractable studies can identify potential leachables, and extractables and leachables (E&Ls) should be evaluated during development of the impurity control strategy. Currently, there is a lack of specific regulatory guidance on how to risk assess E&Ls; this may lead to inconsistency across the industry.

In chemico, in vitro and in vivo comparison of the skin sensitizing potential of eight unsaturated and one saturated lipid compounds.

The applicability of the Direct Peptide Reactivity Assay (DPRA), the KeratinoSens™ assay and the human cell line activation test (OECD Test Guidelines 442C, 442D, 442E) in predicting the skin sensitising potential of nine lipid (bio)chemicals was investigated. The results from the three assays were integrated using a published prediction model (PM), by which skin sensitisation is predicted if at least two of the three assays yield positive results. Of the eight test substances that were classified as non-sensitisers using available Guinea Pig Maximisation Test (GPMT) data, only five were correctly predicted as 'negative' in the PM.

Modification of the surface of superparamagnetic iron oxide nanoparticles to enable their safe application in humans.

Combined individually tailored methods for diagnosis and therapy (theragnostics) could be beneficial in destructive diseases, such as rheumatoid arthritis. Nanoparticles are promising candidates for theragnostics due to their excellent biocompatibility. Nanoparticle modifications, such as improved surface coating, are in development to meet various requirements, although safety concerns mean that modified nanoparticles require further review before their use in medical applications is permitted.

Assessing safety of extractables from materials and leachables in pharmaceuticals and biologics - Current challenges and approaches.

Leachables from pharmaceutical container closure systems can present potential safety risks to patients. Extractables studies may be performed as a risk mitigation activity to identify potential leachables for dosage forms with a high degree of concern associated with the route of administration. To address safety concerns, approaches to toxicological safety evaluation of extractables and leachables have been developed and applied by pharmaceutical and biologics manufacturers.

Biotransformation and toxicokinetics of the insect repellent IR3535® in male and female human subjects after dermal exposure.

The absorption and excretion of the insect repellent IR3535(®) was studied in human subjects (five males and five females) after dermal application of approx. 3g of a formulation containing 20% IR3535(®), i.e.

Developmental effects of coumarin and the anticoagulant coumarin derivative warfarin on zebrafish (Danio rerio) embryos.

Coumarin and warfarin, two substances which are intensively metabolized in animals and humans, were tested for teratogenicity and embryo lethality in a 3-day in vitro assay using zebrafish embryos. Warfarin is a coumarin derivative, but in contrast to the mother substance warfarin has anticoagulant properties. Both substances produced teratogenic and lethal effects in zebrafish embryos.

Alternative (non-animal) methods for cosmetics testing: current status and future prospects-2010.

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.

Zebrafish (Danio rerio) embryos as a model for testing proteratogens.

Zebrafish embryos have been shown to be a useful model for the detection of direct acting teratogens. This communication presents a protocol for a 3-day in vitro zebrafish embryo teratogenicity assay and describes results obtained for 10 proteratogens: 2-acetylaminofluorene, benzo[a]pyrene, aflatoxin B(1), carbamazepine, phenytoin, trimethadione, cyclophosphamide, ifosfamide, tegafur and thio-TEPA. The selection of the test substances accounts for differences in structure, origin, metabolism and water solubility.

Zebrafish teratogenicity test with metabolic activation (mDarT): effects of phase I activation of acetaminophen on zebrafish Danio rerio embryos.

The zebrafish Danio rerio embryo test with metabolic activation (mDarT) was developed to assess the teratogenic effects of proteratogens. In this study induced rat liver microsomes (RLM) were used as a mammalian metabolic activation system (MAS), since they contain various cytochrome P450 (CYP) isoforms at high concentrations. Acetaminophen (APAP) is considered not to be teratogenic in vivo, however, in vitro teratogenic effects were observed, e.

Development of a new screening assay to identify proteratogenic substances using zebrafish danio rerio embryo combined with an exogenous mammalian metabolic activation system (mDarT).

The assessment of teratogenic effects of chemicals is generally performed using in vivo teratogenicity assays, for example, in rats or rabbits. We have developed an in vitro teratogenicity assay using the zebrafish Danio rerio embryo combined with an exogenous mammalian metabolic activation system (MAS), able to biotransform proteratogenic compounds. Cyclophosphamide (CPA) and ethanol were used as proteratogens to test the efficiency of this assay.

Kinetics of 3-(4-methylbenzylidene)camphor in rats and humans after dermal application.

The toxicokinetics of 4-MBC after dermal administration were investigated in human subjects and in rats. Humans (3 male and 3 female subjects) were exposed to 4-MBC by topical application of a commercial sunscreen formulation containing 4% 4-MBC (w/w), covering 90% of the body surface and resulting in a mean dermal 4-MBC dose of 22 mg/kg bw. In rats, dermal 4-MBC doses of 400 and 2000 mg/kg bw were applied in a formulation using an occlusive patch for 24 h.

Toxicokinetics and biotransformation of 3-(4-methylbenzylidene)camphor in rats after oral administration.

3-(4-Methylbenzylidene)camphor (4-MBC) is an UV-filter frequently used in sunscreens and cosmetics. Equivocal findings in some screening tests for hormonal activity initiated a discussion on a possible weak estrogenicity of 4-MBC. In this study, the toxicokinetics and biotransformation of 4-MBC were characterized in rats after oral administration.

Activation of estrogen receptor alpha and ERbeta by 4-methylbenzylidene-camphor in human and rat cells: comparison with phyto- and xenoestrogens.

4-Methylbenzylidene-camphor (4-MBC) is an organic sunscreen that protects against UV radiation and may therefore help in the prevention of skin cancer. Recent results on the estrogenicity of 4-MBC have raised concerns about a potential of 4-MBC to act as an endocrine disruptor. Here, we investigated the direct interaction of 4-MBC with estrogen receptor (ER) alpha and ERbeta in a series of studies including receptor binding, ER transactivation and functional tests in human and rat cells.