No abstract

: Medicinal plants produce secondary metabolites with special biological activities, which may be used as new therapeutic alternatives. For instance, tea tree essential oil (TTO) was shown to exert antimicrobial, antifungal, anthelmintic, antiviral, anti-tumor and anti-inflammatory activities. Due to their thermal instability, active principles can be easily degraded by physicochemical processes; therefore, they must be protected to increase their time of action and improve their controlled release. The aim of this review is to report formulations making use of encapsulated TTO as the active ingredient. Micro and nanoencapsulated systems proved to be more thermostable than TTO and to exert better antimicrobial, antifungal, antiparasitic and larvicidal effects. Nanoencapsulation also reduced the oil toxicity. Emulsified and hybrid systems developed by various methods proved to be promising for the pharmaceutical industry, because they showed improved repellent, antibacterial, antifungal and anti-inflammatory activities. Liposomal formulations produced by hydration of lipid films exhibited constant rate of terpineol-4 release. In addition, their incorporation into biomaterials, such as sponges, nanofibers and films, showed great potential for treating infections. Mainly due to the advantages of their incorporation into new drug delivery systems over conventional formulations, there is interest in the development of systems containing TTO as a pharmaceutical ingredient of plant origin.

This study aimed to develop films of chitosan (CSF) associated with pentoxifylline (PTX) for healing cutaneous wounds. These films were prepared at two concentrations, F1 (2.0 mg/mL) and F2 (4.0 mg/mL), and the interactions between the materials, structural characteristics, in vitro release, and morphometric aspects of skin wounds in vivo were evaluated. The formation of the CSF film with acetic acid modifies the polymeric structure, and the PTX demonstrates interaction with the CSF, in a semi-crystalline structure, for all concentrations. The release for all films was proportional to the concentration, with two phases: a fast one of ≤2 h and a slow one of >2 h, releasing 82.72 and 88.46% of the drug after 72 h, being governed by the Fickian diffusion mechanism. The wounds of the mice demonstrate a reduction of up to 60% in the area on day 2 for F2 when compared to CSF, F1, and positive control, and this characteristic of faster healing speed for F2 continues until the ninth day with wound reduction of 85%, 82%, and 90% for CSF, F1, and F2, respectively. Therefore, the combination of CSF and PTX is effective in their formation and incorporation, demonstrating that a higher concentration of PTX accelerates skin-wound reduction.