Hidroxiapatite de origem marinha com ferro utilizada na constituição de um protetor solar

Abstract

INTRODUCTION: This study aimed at the valorisation of a by-product, to make it as an effective protector for the UV radiation, and to incorporate it in a creamy base formulation. We used the cod fish bones considering their local availability as by-product of the food industry. Hydroxyapatite (HAp), the main component of codfish bones, is a biocompatible calcium phosphate that could be used for the formulation of a sunscreen. For this material becoming effective in ultraviolet absorption, iron has to be incorporated in its structure. Therefore, the objective of the present work was the improvement of the UV light absorbing properties of the hydroxyapatite, to obtain a material which was both biocompatible and UV filtering. METHODS: To incorporate the iron in the calcium phosphate structure, bones were places in contact with the solutions containing the iron ion; contact times of for 3 and 5 hours were tested. Different sources of iron - FeCl2, C6H10FeO6 and Fe (NO₀) ₀ - were used, to see which of these had most effective incorporation rate. Subsequently, the bones were calcined and crushed manually. To optimize the particle size of the powders, to be incorporated into a cosmetic product, the samples underwent two kind of treatment - high energy ball milling and ultrasound. Creams with different powder concentrations and/or treatment were formulated, to study what the ideal combination. The best creams were tested to determine the SPF - Sun Protection Factor – the UVA / UVB ratio and color under ambient conditions and temperature of 60º C. RESULTS: The best conditions were obtained with a 3hour treatment in FeCl2 solution. Between the two treatment methods of the powder described above, the high energy ball milling gave better results. Gathered all these conditions, then followed by the development of a protective cream. The protective cream had a reddish color (color coordinates: L = 53.55, a = 16.93 and b = 16.98 at room temperature and L = 31.49, a = 15.00 and b = 12.11 at 60 o C), a SPF value around of 3.5; the UVA / UVB ratio it was equal to 1. CONCLUSIONS: This work it was shown the feasibility of producing this type of cosmetic product, derived from food by-product. It should be noted that the protection factor is lower than that of commercial formulations - using TiO2 - however, the prepared product has a UVA / UVB ratio equal to 1, a factor that is better than that of the commercial products.

Date of Award	14 Jan 2016
Original language	Portuguese
Awarding Institution	Universidade Católica Portuguesa
Supervisor	Clara Piccirillo (Supervisor)