Publication date: Available online 29 June 2017
Source:Photodiagnosis and Photodynamic Therapy
Author(s): Fernanda Belincanta Borghi-Pangoni, Mariana Volpato Junqueira, Sabrina Barbosa de Souza Ferreira, Larissa Lachi Silva, Bruno Ribeiro Rabello, Lidiane Vizioli de Castro, Mauro Luciano Baesso, Andréa Diniz, Wilker Caetano, Marcos Luciano Bruschi
Hypericin (Hyp) is a natural photoactive pigment utilized in the treatment of different types of cancer and antimicrobial inactivation using photodynamic therapy (PDT). Hyp is poorly soluble in water conducing to problems of administration, getting closeness contact with the site, and availability. Therefore, this study aimed to develop bioadhesive thermoresponsive system containing Hyp for local PDT. I this sense, carbomer 934P, poloxamer 407, and Hyp were used to prepare the thermoresponsive bioadhesive formulations. They were characterized as sol-gel transition temperature, mechanical, mucoadhesive, rheological (continuous flow and oscillatory) and dielectric properties, syringeability, in vitro Hyp release kinetics, ex vivo permeability, and photodynamic activity. The formulations displayed suitable gelation temperature and rheological characteristics. The compressional, mechanical and mucoadhesive properties, as well the syringeability showed the easiness of administration and the permanence of the system adhered to the mucosa or skin. The dielectric analysis helped to understand the Hyp availability, and its release presented an anomalous behavior. The system did not permeate the pig skin nor rat intestine and showed good biological photodynamic activity. Therefore, data obtained from the bioadhesive system indicate a potentially useful role as a platform for local hypericin delivery in PDT, suggesting it is worthy of in vivo evaluation.