ABSTRACT
The Franz cells permeation assay has been performed for over 25 years. However, the advent of nanotechnology created a whole new world, especially with regard to topical products. In this new global scenario an increasing number of nanostructure-based delivery systems (NDSs) have emerged and a global warning relating to the safety of these NDSs is arising. This work studied the efficacy of the Franz cells assay, comparing it with the radiolabeling biodistribution test. For this purpose a formulation of sunscreen based on an NDS was developed and characterized. The results demonstrated both that the NDS did not present in vitro cytotoxicity and that the radiolabeling biodistribution test is more precise for the evaluation of NDS cosmetics than the Franz cells assay, since it detected the permeation of the NDS at a picogram order. Due to this fact, and considering all the concerns related to NDSs and nanoparticles in general, more precise methods must be used in order to guarantee the safe use of these new classes of products.
Subject(s)
Drug Carriers/chemistry , Nanoparticles/chemistry , Skin Absorption , Sunscreening Agents/administration & dosage , Sunscreening Agents/pharmacokinetics , Animals , Cell Line , Drug Carriers/toxicity , Emulsions/chemistry , Emulsions/toxicity , Haplorhini , Mice , Nanoparticles/toxicity , Rats, Wistar , Skin/metabolism , Sunscreening Agents/toxicity , Tissue DistributionABSTRACT
O objetivo deste estudo foi comparar a liberação do p-metoxicinamato de octila (MCO) a partir de três formulações em gel. A primeira contendo o MCO livre, a segunda contendo o MCO incluso em Beta-ciclodextrina (Beta-CD/MCO) e a terceira contendo o MCO incluso em lipossoma (lipossoma/MCO). O estudo de liberação foi realizado em células de difusão do tipo Franzusando membrana artificial de acetato de celulose. A concentração de MCO liberada foi determinada por cromatografia líquida de alta eficiência (CLAE). Os perfis de liberação in vitro mostraram que a inclusão do MCO nesses sistemas de liberação reduziu a liberação do MCO para a solução receptora comparando coma formulação de MCO livre. Entre as formulações de Beta-CD/MCO e lipossoma/MCO, a que liberou menor concentração de MCO para a solução receptora foi a formulação de lipossoma/MCO, mostrando os melhores resultados.
Subject(s)
Cyclodextrins , Liposomes , Sunscreening AgentsABSTRACT
The aim of this work was to investigate whether a 1,3-diacylglycerol moiety can act as enhancer of the photoprotecting action of a new sunscreen of the cinnamate class, owing to its affinity with skin constituents and lower susceptibility to hydrolysis at C-2. The sun protection factors (SPF) for 1,2,3-propanetriol 1,3-dipalmitate-2-p-methoxycinnamate and 1,2,3-propanetriol 1,3-dioctanoate-2-p-methoxy-cinnamate (2.0, 4.5 and 7.5%) were determined. The sunscreen preparations presented SPF values between 4.7 and 16. The results show that although glyceridic esters present higher lipophilicity and are more stable towards enzymatic hydrolysis in vitro, the synthesized triacylglycerols and the standard sunscreen 2-ethylhexyl p-methoxycinnamoyl (EHPM) showed equivalent SPF values for both methods.
ABSTRACT
The aim of this work was to evaluate the correlation between in vitro and in vivo determinations of sun protection factors (SPF) of sunscreen lotions containing the synthetic sunscreen octyl methoxycinnamate. Three sunscreen lotions containing either 2, 4.5 or 7.5% octyl methoxycinnamate were prepared. The in vitro SPFs of these sunscreen lotions were determined according to the spectrophotometric method of Mansur et al. The in vivo SPF values were determined according to the Food and Drug Administration (FDA) method. The results indicate that there was a good correlation between the in vitro and in vivo determinations for the sunscreen lotions examined.
