The main objective of this work was to develop a nanoemulsion based on linseed oil and betulinic acid, stabilized with Pluronic F127 and polyglycerol polyricinoleate, for anticancer applications. The nanoemulsions were synthesized by ultrasound and evaluated for in vitro cytotoxicity, particle size, polydispersity index, zeta potential, morphology, encapsulation efficiency, storage stability, rheology and in vitro release kinetics. In vitro cytotoxicity assays were performed by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay (72 h) against HCT-116 (colorectal carcinoma), SNB-19 (glioblastoma), NCI-H460 (lung carcinoma) and L-929 (normal fibroblasts) cells. The determination of 50% inhibitory concentration (IC50) showed an increased selectivity for the emulsified betulinic acid when compared to its free form for the HCT-116 cells. The IC50 values for the synthesized nanoemulsions showed a range from 3.2 to 3.7 µM (HCT-116), 5.6 and 11.5 µM (NCI-H460), 5.8 and 7.3 µM (SNB-19) and > 16.5 µM for normal fibroblasts. In the 48 h in vitro release assays, it presented controlled release explained by the Korsmeyer-Peppas model, releasing 572.25 and 619.95 µg of betulinic acid in a controlled way, generating promising perspectives for the prolonged release of betulinic acid in anticancer applications.

Plant phenolic extracts are widely recognized as an important source of natural antioxidant substances and potential compounds for cosmetic formulations. This study aimed to evaluate the chemical profile, photoprotective and antioxidant activities of stem bark extract of Spondias purpurea L. (ciriguela) and its application in photoprotective formulations. Thirty phenolic constituents were annotated by ultra-performance liquid chromatography coupled with an electrospray ionization quadrupole time-of-flight mass spectrometry in mode negative (UPLC-QTOF-MS2). The stem bark extract antioxidant and chelation potential, expressed in half maximal inhibitory concentration (IC50), showed 6.25 and 352.22 µg mL−1, respectively. The phenolic extract was used as an active ingredient in six sunscreen formulations, with concentrations ranging from 0.2 to 10%. The ultraviolet (UV) protection properties of the formulations were evaluated by sun protection factor (SPF) values obtained in 0.2 mg mL−1 (0.495 to 2.27) and 2.0 mg mL−1 (2.29 to 15.87). The SPF value for the extract (14.37 and 26.16) was high, but there was a reduction in the base formulation. However, these results suggested that the bioactive extracted of stem bark of Spondias purpurea L. has interesting potential to reduce the damage caused by UV radiation and may be utilized as an active ingredient in a sunscreen formulation.

Improving the development of modified release matrix systems strictly depends on selecting an appropriate agent capable of controlling the drug's release. In this study, Adenanthera pavonina galactomannan was investigated as a potential basis for developing a controlled release of rutin. This galactomannan was extracted, purified and characterized by GPC, NMR and FT-IR spectroscopy. The mannose/galactose ratio (M/G) of 1.46 was calculated by the relative area from signals of the anomeric region of 1H-NMR spectrum. The main chain of this galactomannan consists of β(1®4)-D-mannose and α(1®6)-D-galactose linked units (1H-decoupled 13C NMR, 13C DEPT 135º NMR and HSQC spectra). The sustained-release tablets containing rutin and galactomannan were compared with the extensively investigated hydrophilic matrix HPMC. Drug release analysis revealed similar release mechanism for both matrices. A new formulation for controlled drug delivery from water-swellable matrix systems is proposed.

In this work, the allantoin was encapsulated with galactomannan extruded from Delonyx regia, by the spray drying technique. The microparticles obtained were structurally characterized by infrared spectroscopy (IR), thermal analysis, scanning electron microscopy (SEM) and the controlled release profile was evaluated. The results of IR suggested the formation of the polymeric wall of the microcapsules and SEM revealed spherical particles with an average size range of 2.84 ± 0.41 µm. X-ray diffraction showed the loss of crystallinity of the active after encapsulation and differential explanatory calorimetry exhibited the loss of its peak melt. The encapsulation efficiency for the microparticles was approximately 84% for the different environmental conditions. The coating of allantoin with the biopolymer promoted a gradual release of the drug over a period of 6 hours and these results are in accordance with the Brazilian Pharmacopoeia. The set of results obtained in this work is relevant and accredits the system developed as a possible alternative for the formation of encapsulated natural drugs destined to possible treatments of cutaneous cellular regeneration.

This work describes the development and characterization of triglyceride-based magnetic nanocomposites for application in magnetic hyperthermia and controlled drug delivery. The magnetic solid lipid nanocomposites (MSLN) constituted by mixtures of trilaurin-tricaprylin and trilaurin-tricaprin have been successfully obtained by emulsification-solvent evaporation method. The developed MSLNs were subjected to an external oscillating magnetic field and showed significant hyperthermia. The samples were exposed to frequencies of 688 and 869 kHz causing, respectively, a temperature increase of 15.5 and 22.7 °C (trilaurin-tricaprylin) and 17.3 and 26.1 °C (trilaurin-tricaprin). Also, in vitro assays in the absence of magnetic field showed that the triglyceride-based formulations were able first to encapsulate and then to sustained release an antitumoural hydrophobic drug. After 72 h of assay trilaurin-tricaprylin and trilaurin-tricaprin released 73 and 55% of their cargo, respectively. In addition, MSLN exhibited low in vitro cytotoxic activity against human neutrophils.

The binary mixtures of Brij® surfactant and Pluronic® F127 were studied as carriers of griseofulvin. The F127 systems and Brij® 78 (C18H37E20), Brij® 98 (C18H35E20) and Brij® 700 (C18H37E100) were prepared in the proportions 10/90, 30/70, 50/50 and 70/30, respectively. The characterizations were carried out by tube inversion, rheology, particle size, and theoretical cmcs. The griseofulvin solubilization tests were performed at 25 and 37 ºC in micellar solutions of 1 wt. % and quantified by UV/Vis. According to the rheological data, the presence of F127 make the F127/Brij 78 70/30 and F127/Brij 98 70/30 mixtures thermoresponsive at concentrations of 30 and 35 wt.%, with transition fluid/gel in the range of 28-30 ºC, ideal for topical use. All of the F127 / Brij 700 mixtures showed moderate distribution polydisperse (PDI < 0.4), as well as mixtures of F127 / Brij 98, with the exception of the mixture with ratio 30/70. Mixtures of F127 / Brij 78 had wide polydisperse distribution (PDI > 0.4). The optimal mixing for oral application would be of F127/Brij 78 because it exhibits greater solubilizing capacity (Scp) of griseofulvin at temperatures of 25 to 37 ºC when compared to F127 alone.