Safety Assessment of Nano-Hydroxyapatite as an Oral Care Ingredient according to the EU Cosmetics Regulation
by
Joana M. Ramis 1,2,*
, Catarina C. Coelho 3,4,5,6, Alba Córdoba 1,7, Paulo A. Quadros 6 and Marta Monjo 1,2,*
Joana M. Ramis 1,2,*, Catarina C. Coelho 3,4,5,6, Alba Córdoba 1,7, Paulo A. Quadros 6 and Marta Monjo 1,2,*
1
Cell Therapy and Tissue Engineering Group, Research Institute on Health Sciences (IUNICS), University of the Balearic Islands, 07122 Palma, Spain
2
Department of Fundamental Biology and Health Sciences, University of the Balearic Islands, 07122 Palma, Spain
3
i3S–Instituto de Investigação e Inovação em Saúde, Universidade do Porto, 4200-135 Porto, Portugal
4
INEB—Instituto de Engenharia Biomédica, Universidade do Porto, 4200-135 Porto, Portugal
5
Faculdade de Engenharia da Universidade do Porto, Universidade do Porto, 4200-465 Porto, Portugal
6
FLUIDINOVA, S.A., 4470-605 Maia, Portugal
7
Balearic Islands Health Research Institute (IdISBa), 07010 Palma, Spain
*
Authors to whom correspondence should be addressed.
Cosmetics 2018, 5(3), 53; https://doi.org/10.3390/cosmetics5030053
Received: 26 July 2018 / Revised: 5 September 2018 / Accepted: 6 September 2018 / Published: 11 September 2018
(This article belongs to the Special Issue Cosmetic Formulation Strategy: From Raw Materials to Packaging by Nanotechnology and Nanobiotechnology's Processes)
Hydroxyapatite nanoparticles (HAP-NP) are incorporated in oral care products such as toothpastes and mouthwashes to treat dental sensitivity or to promote enamel remineralisation. Despite the good performance of HAP-NP in this application, it is important to ensure its safety for consumers. For that reason, the Scientific Committee on Consumer Safety (SCCS) evaluated the safety of HAP-NP as an oral care ingredient, but the issued opinion was not completely conclusive and the SCCS recommended that additional tests should be performed. Here, we used a commercially available human gingival epithelium (HGE) as a non-animal alternative and MTT cell viability, LDH activity, and IL-1alpha production were evaluated after 3.1% HAP-NP treatment for 10 min, 1 h, and 3 h. Moreover, the absorption of HAP-NP in the gingival tissue was assessed by transmission electron microscopy (TEM) analysis. Finally, the dissolution behaviour of HAP-NP in simulated gastric fluid was also investigated. No deleterious effect was observed for HGE tissues incubated with HAP-NP for all time-points and parameters evaluated. Moreover, a complete dissolution of 3.1% HAP-NP in simulated gastric fluid was observed after 7.5 min at 37 °C. In conclusion, our results evidence the safety of HAP-NP for oral care products with the use of an in vitro replacement alternative for human gingival epithelium and a simulated gastric fluid assay.
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Keywords:
hydroxyapatite nanoparticles; human gingival epithelium; oral care; EU cosmetics regulation; safety evaluation; in vitro biocompatibility; dissolution in simulated gastric fluid
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MDPI and ACS Style
Ramis, J.M.; Coelho, C.C.; Córdoba, A.; Quadros, P.A.; Monjo, M. Safety Assessment of Nano-Hydroxyapatite as an Oral Care Ingredient according to the EU Cosmetics Regulation. Cosmetics 2018, 5, 53.
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