Publications by authors named "Vania Rodrigues Leite-Silva"

3 Publications

  • Page 1 of 1

Is Vitamin D Transdermal Formulation Feasible? An Ex Vivo Skin Retention and Permeation.

AAPS PharmSciTech 2018 Jul 4;19(5):2418-2425. Epub 2018 Jun 4.

Department of Pharmacy, University of São Paulo (USP), Sao Paulo, Brazil.

Vitamin D supplementation is important to prevent and treat hypovitaminosis that is a worldwide public health issue. Most types of supplementation are by oral route or fortification foods. The alternative route must be investigated, as transdermal route, for people with fat malabsorption or other diseases that impair the absorption of vitamin D. This study focused on verifying the feasibleness of vitamin D skin retention and permeation with the presence of chemical penetration enhancers (soybean lecithin, isopropyl palmitate, propylene glycol, ethoxydiglycol, and cereal alcohol) at different pharmaceutical forms (gel and cream) through a human skin. The integrity of skin was evaluated by transepidermal water loss (TEWL) during the skin retention and permeation test. The combination of chemical penetration enhancers presented in cream did not compromise the skin, different from the gel that association of cereal alcohol and propylene glycol compromised the skin in 24 h. Gel formulation showed vitamin D detection at stratum corneum in 4 h and at epidermis and dermis in 24 h. Vitamin D demonstrated an affinity with the vehicle in the cream formulation and was detected at the skin surface. No active was found at receptor fluid for both formulations. In conclusion, the vitamin D did not indicate feasibleness for transdermal use probably due to its physical-chemical characteristics such as high lipophilicity since it was not permeated through a human skin. Nevertheless, the transdermal route should be continuously investigated with less lipophilic derivates of vitamin D and with different combination of penetration enhancers.
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http://dx.doi.org/10.1208/s12249-018-1065-5DOI Listing
July 2018

Alternative Methods to Animal Studies for the Evaluation of Topical/ Transdermal Drug Delivery Systems.

Curr Top Med Chem 2018 ;18(4):287-299

Instituto de Ciencias Ambientais Quimicas e Farmaceuticas, Universidade Federal de Sao Paulo, Diadema SP, Brazil.

It is critical to develop an effective understanding of the interaction between the drug, delivery system and skin in order to predict and assess skin penetration and permeation. Experimental models for the assessment of topical and transdermal delivery systems must permit evaluation of these complex interactions. Whilst in the past, animal models were commonly used, recent regulatory guidelines, based on 3R principles (refinement, reduction, replacement), encourage the rational use of animals. Alternative methods have been proposed for use in the development of topical and transdermal delivery systems which are often used in combination. We will review the current state of the art in alternative methods for topical and transdermal delivery systems development, including technologies that can assist in the characterization of skin penetration/permeation studies.
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http://dx.doi.org/10.2174/1568026618666180412153214DOI Listing
June 2018

Development and Evaluation of Lipid Nanoparticles Containing Natural Botanical Oil for Sun Protection: Characterization and in vitro and in vivo Human Skin Permeation and Toxicity.

Skin Pharmacol Physiol 2018 4;31(1):1-9. Epub 2017 Nov 4.

Instituto de Ciências Ambientais, Químicas e Farmacêuticas, Departamento de Ciências Farmacêuticas, Universidade Federal de São Paulo, UNIFESP-Diadema, São Paulo, Brazil.

The use of sunscreen products is widely promoted by schools, government agencies, and health-related organizations to minimize sunburn and skin damage. In this study, we developed stable solid lipid nanoparticles (SLNs) containing the chemical UV filter octyl methoxycinnamate (OMC). In parallel, we produced similar stable SLNs in which 20% of the OMC content was replaced by the botanical urucum oil. When these SLNs were applied to the skin of human volunteers, no changes in fluorescence lifetimes or redox ratios of the endogenous skin fluorophores were seen, suggesting that the formulations did not induce toxic responses in the skin. Ex vivo (skin diffusion) tests showed no significant penetration. In vitro studies showed that when 20% of the OMC was replaced by urucum oil, there was no reduction in skin protection factor (SPF), suggesting that a decrease in the amount of chemical filter may be a viable alternative for an effective sunscreen, in combination with an antioxidant-rich vegetable oil, such as urucum. There is a strong trend towards increasing safety of sun protection products through reduction in the use of chemical UV filters. This work supports this approach by producing formulations with lower concentrations of OMC, while maintaining the SPF. Further investigations of SPF in vivo are needed to assess the suitability of these formulations for human use.
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http://dx.doi.org/10.1159/000481691DOI Listing
August 2018