Levofloxacin (LV) is a hydrophilic broad-spectrum antibiotic commonly used in pulmonary treatment against recurrent infections of Pseudomonas aeruginosa, and particularly in cystic fibrosis (CF) disease. In order to study feasible carriers for LV, solid lipid nanoparticles (SLN) of myristyl myristate were prepared by the ultrasonication method in the presence of Pluronic(®)F68 under different experimental conditions and characterized by dynamic light scattering, optical, transmission and scanning electron microscopy for size and morphology. Alternatively, nanostructured lipid carriers (NLCs) were developed to improve LV encapsulation and storage. SLN showed 20.1±1.4% LV encapsulation efficiency, while the NLCs encapsulated 55.9±1.6% LV. NLC formulation exhibited a more controlled release profile than SLN formulation, but both showed a biphasic drug release pattern with burst release at the first 5h and prolonged release afterwards, demonstrated by in vitro tests. The hydrodynamic average diameter and zeta potential of NLC were 182.6±3.2nm and -10.2±0.2mV, respectively, and were stable for at least 3 months. Additionally, DNase type I was incorporated into the formulations as a "smart" component, since the enzyme could help to decrease the viscoelasticity found in the lungs of CF patients and improves the antibiotic diffusion. FTIR, XRD, DSC, TGA and nitrogen adsorption isotherms of the nanoparticles indicate the presence of the loads in a noncrystalline state. The developed formulation showed an active antimicrobial activity against P. aeruginosa and even against other opportunistic pathogens such as Staphylococcus aureus. The presence of LV-loaded NLCs reduced the formation of a bacterial biofilm, which highlighted the significance of the nanodevice as a new alternative for CF treatment.

In this work, microfiber meshes containing embelin, a poorly water-soluble bioactive agent, were prepared by solubilizing embelin in a biodegradable and biocompatible polymer matrix of poly(e-caprolactone) (PCL). Plain or drug-loaded, highly porous, fibrous membranes with a high area-to-volume ratio were obtained by electrospinning. Non-woven microfibrous meshes were formed by uniform bead-free fibers with a mean diameter of 1.2 lm. Non-porous films were obtained by solution casting, and were used for comparison. The drug-loading content of the prepared systems was appropriate for topical applications. The thermal properties revealed that the crystallinity of embelin significantly decreased, the drug having almost completely dissolved in the PCL fibers. The in situ bioavailability of embelin, an antimycotic agent, is an important aspect to consider in topical drug applications. The drug-loaded systems presented different contact areas with the biological environment. When comparing the ability to expose embelin with the biological environment of the prepared systems, drug-loaded fibrous scaffolds showed a higher bioavailability of the bioactive agent because of an increase by 86% in the area-to-volume ratio, providing an effective area per unit mass that was 5.8-fold higher than that of the film. For the meshes, 90% embelin release was observed after 12 h of exposure to phosphate-buffered saline, whereas for the films a comparable level of release occurred only after 72 h.

EHDA technology was used to encapsulate the water-soluble antiretroviral ddI within PCL particles and stabilize it in the gastric medium where it undergoes fast degradation.

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Drug-loaded nanofibrous scaffolds containing hydrophilic or hydrophobic drugs presented encapsulation efficiency, distribution and release dependent on copolymer composition.

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The main strategies against Triatoma infestans (primary vector responsible for the Chagas disease transmission) are the elimination or reduction of its abundance in homes through the application of insecticides or repellents with residual power, and environmental management through the improvement of housing. The use of plant-derived compounds as a source of therapeutic agents (i.e., essential oils from aromatic plants and their components) is a valuable alternative to conventional insecticides and repellents. Essential oil-based insect repellents are environmentally friendly and provide reliable personal protection against the bites of mosquitoes and other blood-sucking insects. This study investigates, for the first time to our knowledge, the potential repellent activity of Zuccagnia punctata essential oil (ZEO) and poly(ε-caprolactone) matrices loaded with ZEO (ZEOP) prepared by solvent casting. The analysis of its essential oil from aerial parts by GC–FID and GC-MS, MS allowed the identification of 25 constituents representing 99.5% of the composition. The main components of the oil were identified as (−)-5,6-dehydrocamphor (62.4%), alpha-pinene (9.1%), thuja-2, 4 (10)-diene (4.6%) and dihydroeugenol (4.5%). ZEOP matrices were homogeneous and opaque, with thickness of 800 ± 140 µm and encapsulation efficiency values above 98%. ZEO and ZEOP at the lowest dose (0.5% wt./wt., 96 h) showed a repellency of 33 and 73% respectively, while at the highest dose (1% wt./wt., 96 h) exhibited a repellent activity of 40 and 66 %, respectively. On the other hand, until 72 h, ZEO showed a strong repellent activity against T. infestans (88% repellency average; Class V) to both concentrations, compared with positive control N-N diethyl-3-methylbenzamide (DEET). The essential oils from the Andean flora have shown an excellent repellent activity, highlighting the repellent activity of Zuccagnia punctata. The effectiveness of ZEO was extended by its incorporation in polymeric systems and could have a potential home or peridomiciliary use, which might help prevent, or at least reduce, Chagas’ disease transmission.