Study of the dye penetration for topical formulation

MAIRA GASPAR TOSATO; DALILA ORALLO; SANDRA CHURIO; AIRTON A. MARTIN; LELIA DICELIO

Córdoba

Encuentro; XI Encuentro Latinoamericano de Fotoquímica y Fotobiología; 2012

Mycosporine like amino acids (MAA) were isolated from a marine red alga and were identified as porphyra-334 and shinorine. MAA are photoprotector molecules and antioxidants [1], suggesting potential application in prevention and therapeutic treatment of diseases related to the production of free radicals and UV irradiation of the skin which acts as a natural barrier to topical products. We investigated the effects of polymers gels (Poloxamer 407 and Pluronic ® F-127) as in vitro delivery systems [2] of MAA in pig skin. These triblock copolymers are biocompatible, have low toxicity and may be used as carriers for medical and pharmaceutical drug delivery [3-5]. The polymers gels were prepared according to the method described by Schmolka [6]. Appropriate amounts of PL-127 and PO 407 to yield 20, 27 and 30% (w/w) gels were slowly added to cold Milli-Q water (4 - 5º C) with constant stirring during 40 min. Dispersions were left overnight to ensure complete dissolution and clear solutions formed. Rheological measurements dependent on the temperature of the gels were carried out to determine the viscosity at different shear rates. In vitro release studies of the MAA were carried out using pig skin by confocal Raman spectroscopy. Raman spectra were obtained by with a 785 nm laser excitation in different depths for the low (900-1800 cm-1) frequencies showing alterations in lipids and protein peaks. The skin was used without the topical formulations as a reference.