Solid lipid nanoparticles: encapsulation of tretinoin to topical application

Author(s)

Daniela Missiani Ridolfi

• Document type: Master's Dissertation
• Press: Campinas, SP.
• Institution: Universidade Estadual de Campinas (UNICAMP). Instituto de Química
• Defense date: 2011-02-18

Examining board members

Nelson Eduardo Duran Caballero; Lucimara Gaziola de la Torre; Renato Atilio Jorge

• Advisor: Nelson Eduardo Duran Caballero

Abstract

Tretinoin (all-trans retinoic acid) is employed in the topical treatment of various skin diseases, however, its uses is strongly limited by their side effects and high chemical instability. In this work tretinoin was encapsulated in solid lipid nanoparticles (SLN-TRE) and SLN coated with chitosan (SLN-Chitosan-TRE). Both particles exhibited high entrapment efficiency, high physical stability and spherical morphology. The SLN-chitosan-TRE presented lower crystallinity compared to SLN without chitosan. The loading capacity of nanoparticles was limited by the low solubilization rate of tretinoin in the melted lipid at the preparation's conditions. The addition of ethanol in the nanoparticles preparation increased the loading capacity, however the dispersion stability was altered (the SLN without chitosan remained stable by only one month and the SLN with chitosan destabilized after preparation). Both particles were not cytotoxic to either fibroblasts or keratinocytes cells. The tretinoin encapsulation in SLN decreased significantly its phototoxicity, which shows a protector effect by the lipid matrix. The SLN-Chitosan-TRE exhibited high antibacterial activity against the main bacteria involved in the acne (S. epidermidis and P. acnes) and against the S. aureus which is involved in skin infections. The results obtained in this work allows us to conclude that the SLN, with and without coating with chitosan, have a great potential for encapsulation of tretinoin in dermal application. The coating with chitosan can improve the SLN properties as carrier for tretinoin because the SLN-Chitosan-TRE exhibited antibacterial activity against bacteria involved in skin infections and therefore can improve the therapeutic efficacy in the topical treatment of acne and other skin diseases (AU)

• FAPESP's process: 09/02210-7 - Solid Lipid Nanoparticles: encapsulation of tretinoin in topical applications.
• Grantee: Daniela Missiani Ridolfi
• Support Opportunities: Scholarships in Brazil - Master